The Best of AFN IV

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Edited by Jack & Dorothy Drewes

A m e r i c a n F i r e w o r k s N e w sAFN


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THE BEST OF AFN IVEdited by Jack & Dorothy Drewes

Copyright 2000 byRex E. & S.P., Inc.

Published by

American Fireworks NewsHC67 - Box 30Dingmans Ferry, PA 18328-9506

All rights reserved.

ISBN 0-929931-15-7

Printed in

The United States of America

Warning: This publication contains descriptionsand pictures of fireworks. The informationcontained herein is based on the authors'experiences using specific tools and ingredientsunder specific conditions not necessarilydescribed in the articles. No warranties are made,or implied. Readers are cautioned that they mustform their own opinion as to the application of anyinformation contained herein.

Notice: Concerning any offer found in this publicationto sell or transfer products or information that aresubject to governmental regulation, such sales ortransfers of the product or information will be madein accord with Federal, State or local laws applicableto the buyer or transferee, as determined by suchregulation.

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CONTENTSStarting Out 7

Ordering 9

STARS & SMALL DEVICES

Cut Sta rs 11Method of Production of Micro Stars 12Bargains in Odd Places 12An Interes ting Cut Star Method 13Cap Crap 13Pill Box Stars 13Making Comets 15Further to My Quest for Good Comets 15Cushioning Comets 15

Latex Gloves Reduce Static Hazard 15Blue & Orange Go Getters Without Magne-sium 16Testing Sta rs 19Kitchen Pyro at Vulcan' s Forge 19Brilliant Illuminating Silver Electric Non-Sizzling Red Comet Shower Stars 20

Sift Those Chemicals 21Priming Comet Shell s 22Water Bottle Salute 23New Formulas for Colored Sparklers 24Colored Sparkler Update 25Super Silver Fou nta ins 25

Lightning Bolts 26Paper Plugs 26Safety Issues Cloud Kitchen Utensil Use.. 27Politically Correct Pyro Tool 27Cones Revisited 28Black Powder Burn Rates 29Black Powder Doesn't Need Machinery .... 30Tissue Paper Tip 31Perfect Paper Tape Tubes 32Silk Screened Fireworks 32Simpson's Spark Spinner 33Mini Founta ins/Sp arklers 34Smoking Cap Stix 35Easy Firecracker Mortar 36Katydids - Repeating Firecrackers 37Triangle Pyro Cases 38

LARGER DEVICES & NOVELTY ITEMS

Yours, Mine & Ours 39The Construction, Care & Feeding of theCajun Pyrotechnical Sawed-Off ShotgunMine 42

Gold Lampblack Sta r Mines 46Don't Mix It 46

A Heretic's Guide to Roman Candles 47Keep the Kids Happy With This One 50

My First Girandola 51

Glittering Sun se t 52Glittering Thu nde r Aerolites 54Making Plugs the Hard Way 57Aerial Flashlight Salute Candles 58Niagara Falls - A 4th of Ju ly Favorite 62The Poor Man's Waterfall 66Frogs 68Paper Freebies 70Tennis Ball Gas Cannon 71Dress Up Those Spinning Wheels 72Wild About Wheels 73Steel Wool Redux 73Driver Basics 74

The Tourbillion Revisited 76Pyros Beware the Month of Ju ne 77

ROCKETS

Easy to Make Fuse for Better RocketIgnition 77

Priming Give Positive Ignition 78Sure Method of Parachute Ejection for

Rockets 79Chain Fusing Visco 79Sticky, Sticky 79Experiments with Miniature Rockets 80

Visco Ignition Transfer 81Hobby Electric Launcher 82Two-Stage Whistle Rockets 84Parachu te Rockets 86Hints & Tips 88The Spoolette Rocket 89Sky Rocket Performance Characteristics. 90Rocket Nozzles 92Ground Testing Rocket Motors 93Bottle Rocket Launcher 94

AERIALS

Poly-Lube Coating 95Product Warning-Nitrocellulose Products 95Easy Made Shell Time Fuse 96Crossmatching Shells the Easy Way 96Make Your Own Mortars 97Small Aerial Ins ert s.. ., 98The How-Do-You-Do-That Multi-Break

Shell 100Another Method of Making Round Shell

Paper Casings 101Easily Made 3" Paper Ball Shell Molds ... 102More on Making Round Paper Shell

Casings 103Hint of the Month 103

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Uncle Tom's Fluffy Rice Hulls 103A Couple of Formulas for Meal Coated

Rice Hulls 104Pyrotechnics by Microscope 105Rolling Bowls 105Converted Cement Mixers 106Hints &Tips 107

CHEMICALS & OTHER INGREDIENTS

Chemical Risks 108Pyro Roulet te - Safety Issues 110Caution About Using Non-Proven

Oxidizers 112Make Your Own Potas sium Nitrate 113More on Potassium Nitrate/Fer tilizer 115

Potassium Nitrate/Fert ilizer Update 116Making Better Charcoal 117Effects of Water on Compositions 117Purifying Chemicals by Recrystallization 118Mining the Pyro Tailings Heap 120Coax Cable for Lancework 120Spherical Titanium Offers Reduced

Sensitivity 121Inexpensive Mills 121

BLACK MATCH & MISC. MACHINERY

Simple Ram Modification Ensures

Improved Comet Ignition 122A Pressing Concern 123Inexpensive Press for Pyro Use 124Installing a Pressure Gauge 125Discussion of Pressing Forces 126Clip-Match 127Cheap & Easy Quickmatch 128Easily Made High Performance Black

Match 129E-Z Formable Black Match 129Another Match Making Machine 130Match Making Machine 132Caution: Very Fas t "Black Match" 133

DISPLAYS, DEVICES & EQUIPMENT

Display Tip of the Month 135My First Board 136Safety & Reliability in Shooting Boxes ... 137

Quick & Easy E-Match Fusing of Visco-Fused Items 138

Fireworks & Electronic Components 138Thoughts on Electric Match 139Testing Electric Matches 140Novel Uses for Sticky Match 142NoMatch Fron t Technique 144Launching Rocket Flights With

NoMatch 146Sticky Match Aids Set Piece

Construction 147NoMatch Delays 148Fun With NoMatch 149Constructing Set Pieces & Other Devices

From Consumer Fireworks 151CD Firing Box From Salvaged Par ts 154

Ball Milling 164Burn Rate of Fireworks Compositions.... 170Peak Shell Accelerations 174Lift Charge Loss 175Dud Shell Hazard Assessment: NFPA 176Dud Shell Hazard Assessment: Mortars . 180Using Salutes in Blasting Operations 184Steel vs Cardboard vs HDPE Mortars 185HDPE Mortars for Multi-Break Shells .... 187More on Mortars 188Non-Sparking Magazine Interiors 190Using HDPE Mortars for Repeat Firing

of Displays 191

Simple Measurements of Aerial ShellPerformance 192

Mortar Separations in Troughs 195Color Coding Mortars 198Shooter' s Personal Checklist 199The Wedding Shoot 200Setting Up & Shooting a Pyromusical

Barge Show 202Hobby Magazine Locks 204

MISCELLANEOUS

The Magic of Professional Pyro Adhesive 204

Better Hydrogen Balloons ThroughChemistry 205

Colored Fire Products Brighten WinterFlames 206

Nitro Millennium Cartoon 208

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TH

PREFACE TO THE 4 VOLUMEIt's hard to believe that five years havepassed since we introduced The Best of AFNIII. It seems like such a brief period, yet thefireworks experimenters and writers whobless American Fireworks News with theirarticles each month have managed to give usenough work to make this the biggest of thethree Bests. And we have enough great arti-cles left over to get started on Best V. Indeed,we do owe it all to those fine people who wantto share their fireworks information with theworld.

Eighty-three (83) pyro writers are representedin these pages. What a cross-section of in-credible fireworks knowledge is found in thatgroup! None of this would be possible withouttheir courage in discovering this fireworksinformation and then deciding to pass italong to other fireworks enthusiasts.

The fireworks scene has changed a great dealsince our first tentative steps with the skinny

Best of AFN (later absorbed into Best II). Thatwas a little over ten years ago but develop-

ments have been so fast that it could havebeen one hundred. We've seen effects such asglitter and strobe emerge from the obscure orsecretive to main line effects that everyonecan achieve. We've seen rapid development inenthusiasts becoming hobbyists and thenbecoming professionals. We've seen techno-logical developments such as displays thatused to be fired with guys running around inthe dark with red fusees to wireless shootingsystems and computer-operated displays.

The Best series is keeping pace with thosedevelopments. Best IV contains some trulyadvanced pyrotechnic information, such asmortar separations, and fusing problems,and other display situations. But we man-aged to keep some basic material availabletoo, and a whole bunch of how-to articles. Weare very pleased with some of these how-toarticles, because they show how easily ob-tained Consumer Fireworks items can beused to make display-quality devices. Andnew developments like StickyMatch ju stmake it so much easier!

It's time to get started with your new book. Ifyou are rather new to all this, I urge you tobegin with the very first two articles,STARTING OUT and ORDERING. They werewritten by the fellow who wrote IntroductoryPractical Pyrotechnics, a book that we highlyrecommend for anyone who wants to dohobby fireworks in a systematic and, well,practical manner. These two articles are afitting beginning ofThe Best of AFN IV.

As you work your way through the book,

please keep in mind that an accident usuallyleads to very dire consequences, both physi-cal and legal. It is healthy to keep remindingyourself that things happen fast in high en-ergy reactions, so careful workmanship andgood housekeeping are essential.

Fireworks clubs offer great opportunities forevery fireworks enthusiast, regardless of hisexperience. We asked Ken Barton, Presidentof the Texas club to tell us about such clubs:

REASONS FOR JOINING AFIREWORKS CLUB

Pyrotechnic Artists of Texas has been in exis-tence only since 1997 but has already cre-ated subtle changes in Texas fireworks, andmore dramatic changes in the lives of itsmembers. Many PAT members have learnedmuch about pyrotechnic safety and at leastfive, possibly ten PAT members have gone onto get their Texas Pyrotechnic Operator's Li-cense as FireAnts.

We in PAT have become more exposed to thefireworks industry and its products, and ourchildren have also experienced more thrillswith fireworks at our events. (The smiles at-test to the happiness.) We have also learnedmore about Texas and federal fireworks laws,and that knowledge keeps us out of difficul-ties we'd rather not experience the hard way.

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STARTING OUTOne of the hard things in any endeavor is get-ting started. There you are at home - you knowyou want to get involved in amateur pyrotech-nics, you may have just recently discoveredthat you are not alone and that there are thou-sands of amateur fireworkers all over the world,but you are still at a loss about how to start. Itseems so daunting - there is so much to learn,you have to gather together materials, and youwant to do it safely. Where to begin?

In my opinion, acquiring knowledge is the firstand most important step. Knowledge is the keyto success and survival. Let's face it - fireworksare dangerous, and the only way to reduce thatdanger is through good working habits andknowledge. If you are going to use flash bags tobreak your shells, then it is important that youknow how to mix and handle flash powder. Ifyou want to begin modifying existing formula-tions then it is important that you know that amixture of a chlorate, a nitrate and finely di-vided aluminum is known as a "Death Mix".Why? Because some books have formulationsthat contain such a mixture, or you may some-day be tempted to use chlorate if you happen torun out of perchlorate. In any case, this chlo-rate/nitrate/ aluminum mixture can occa-sionally suddenly heat up and catch fire or ex-plode, and the inexperienced worker shouldavoid such mixtures. Where do you find thisknowledge? Well, there is very good news -there are numerous sources of that informationnow available, due to the efforts of groups likethe Pyrotechnics Guild International, authorslike Dr. Shimizu, and journals such as AFN. Inmy opinion, you cannot buy too many books,tapes, and magazines. However, buying them

all is expensive, and so you might want to pri-oritize your purchasing order. I would suggestthe following order:

First, I would suggest that you buy my book ataround $40 (shameless plug!). I'm not justsaying this because I wrote the thing, but be-cause I wrote it to fill a gap in the existing lit-erature. It was designed to be a lab manual forthe absolute beginner.[Introductory Practical Py-rotechnics, available from Skylighter.]

Which book to buy next depends a little on yourgoals and inclinations. I personally enjoy read-

ing and rereading Dr. T. Shimizu's book "Fire-works: The Art, Science and Technique". It isprimarily written with an eye towards aerialshells, and it is written by a scientist and dis-cusses some of that aspect, as well as focusingon the techniques. It's a bit pricey at around$70, but I have read my copy ragged. I don'tthink anyone will go wrong buying it. Alterna-tively, one could spend about the same moneyto buy the Best of AFN numbers II and III(Where is Best of AFN I ? Best of AFN II ate it).These are collections of best how-to articles of

AFN, and include technical, craft, scientific andhumorous articles. The articles were mostlywritten by amateurs for amateurs, and dealwith their trials, tribulations, successes andlearning-experiences. Overall these collectionsform a mine of information.

There are other books available, including theRev. Lancaster's book ("Fireworks, Principles &Practice", which is an excellent technical bookon many aspects of fireworks), and the afford-able but somewhat out-of-date books by Davisand Weingart. These latter books are very inter-

esting sources of constructional details, butmany of the formulas are considered outdatedand too dangerous for modern use.

Once one progresses past the stage of rank be-ginner you will want to consider books such asBill Ofca's Technique in Fire series, and thevarious educational books by B. and K.Kosanke, Bleser, Oglesby, etc.

Another excellent source of information ismagazines, newsletters and journals. Appar-ently you already know about AFN. Anothergood source is club newsletters. You willprobably want to join the PGII, and they sendout a bulletin that contains a lot of informationabout PGII events and technical articles aboutthe construction of fireworks. The advertise-ments are also an excellent place to search forsuppliers. Recently I have been very impressedwith the newsletter put out by the Florida Pyro-technic Arts Guild.

Of course, you will want to search out and joinyour local pyrotechnic club (if you are luckyenough to live in an area that has one). The ad-vantages are numerous - most importantly,

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they can give you hands on mentoring. Manyclubs will often host informal classes, and they

can help you gain experience to get yourshooter's certification, and they will know thelocal laws and regulations.

However, not everyone is lucky enough to live inthe area of a pyrotechnics club. There are manyparts of the country without. In some cases youmight be able to find a local mentor. You cantry to find one by advertising in AFN, the PGIIBulletin, or on the Internet (below). You canalso get the next best thing through videos.There are numerous videos available throughAFN and through private individuals. Adver-

tisements for these videos can be found in theback of AFN, the PGI Bulletin, etc. There areboth "convention videos" and "topic videos". Theformer cover talks and classes given at variousconventions, and may have from five to ten dif-ferent short classes or topics. The latter are"purpose made", and cover topics such asmaking cut stars, making single and multi-break shells, shooters safety, etc.

Of course, one of the best learning experiences(short of working with an experienced fire-worker) is to attend a convention, such as the

annual PGI convention, Western Winter Blast,or some of the more local conventions such asFall Florida Fireworks Festival, the SummerFireworks Festival, etc. The larger conventionsnot only have lots of shooting every evening, butthey have full schedules of classes and semi-nars. In fact, they often have to schedule two orthree talks/classes at the same time, and theproblem lies in selecting from this cornucopia ofpossibilities. In addition, the contacts you makecan lead to many learning opportunitiesthroughout the entire year - for example, dur-ing my first convention I met people who freely

said "call me if you have questions".

Then there is the Internet. Beginners shouldapproach the Internet with caution, both pyro-technically and socially. ANYONE can publishanything on the Internet - there is no censor-ship for content or quality. There have beenmany cases where malevolent or ignorant peo-ple have published dangerous information "recipes" which have such high risk factors thatI shudder to think about them. On the otherhand there is a lot of very good information outthere - award winning fireworkers and profes-

sionals also publish on the Internet. One goodplace to start is to browse the world wide web

starting at my web page: www.pyrosafety.comPeople have told me that it's a good page, and ithas a good list of pointers to good information.

Another Internet resource is the Usenet news-group rec.pyrotechnics. Unfortunately,about two-thirds of the postings on rec.pyro are... how do I say this... "ca ca". Few are of anyvalue. How can you tell them apart? Well, firstof all you should "lurk" (just read without writ-ing a lot of stuff). After a few weeks I think itbecomes obvious who are the serious firework-ers... They cite examples, they quote sources

such as Shimizu, they explain the experimentalbasis for their conclusions, and they generallydiscuss issues in a calm and mature fashion(even the most knowledgeable occasionally getangry when faced with a particularly dense anddangerous individual). Rec.pyro also aboundswith "flamers", people who are rude, and whoenjoy ad-hominem as an art form... don't letthem discourage you.

There are also a few semi-hidden mailing lists.Somebody will invite you to join one or more ofthese when you start to get noticed as being a

serious poster on rec.pyro. Yes, I know this is alittle elitist, but the people who manage thesemailing lists have established this policy to tryto keep the signal/noise ratio high. In fact,these mailing lists were pretty much formed asa refuge from the garbage on rec.pyro

Finally, I would like to give you some anti rec-ommendations - books or pamphlets that areSO bad they deserve special mention. High onthis list are The Anarchists Cookbook, RagnarsGuide to the Recreational Use of Explosives,The Big Book of Mischief, The Terrorists Hand-

book, and Phone Phreaking and Kewl Bombz.In fact, anything with typography of the sort"kewl bOmz" is automatically suspect. Thereare a lot of kids who delight in copying and re-editing the same garbage, and passing itaround. For some reason they have developedthe use of alpha-numeric substitution for pho-netic spelling, along with random capitalization(They s33m to thlNK it is k3wl!). Also, many ofthe books from the militia movements are of ex-ceedingly low quality.

Start getting books, and start READING. TIP

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ORDERING

Some of the questions I often get over theInternet is "What should I buy?", "How muchshould I buy?" and "Where do I buy it?".These are all excellent questions. Beginnersdon't want to buy useless chemicals, paper orplastic products, or buy far too much or fartoo little of something. They also don't wantto pay too much, or receive bad material, orhave somebody take their money and not de-liver the promised goods. The good news isthat it is possible to determine what oneneeds by oneself. The bad news - nobody has

a "kit" that one can buy, and so everyone hasto figure it out for themselves.

The key to the first step is planning andvisualization. And the first step of planning isto set goals. One can hardly plan on how toget "somewhere" if one doesn't have a"somewhere" as a goal. Oh, I suppose a per-son could just randomly do things until theydiscover that they have completed a project,but that's inefficient (and generally very dan-gerous in pyro!). So, a beginner would be welladvised to set one or more goals. There is

something to be said for starting with simpleprojects, and working up to more complexgoals. This helps give the person practice inhandling fireworks, and helps build confi-dence as each small project succeeds.

Thus, let us say a person's prime goal was tomake a 3" round shell with color changingstars. This is where the beginner must eitherrely on local tutoring, or where reading,knowledge and visualization are critical. Theperson must read up on the topic until hecan visualize each step. The books I men-

tioned in a previous article are a good placeto start. This reading will help determinewhat materials and tools are needed. For ex-ample, the building of a 3" round shell hasseveral subgoals built into it - the shell con-sists of hemis, and requires a quickmatchleader which contains black match, lift pow-der, time fuse, cross match, burst, and stars(how about the gun to fire it?). This is whereflowcharts come in handy. One can use theseto help plan out projects and to help deter-mine proper sequencing. For example, sincehome-made meal is used in making coated

rice hulls, black match, cross match, andpriming stars, this material should be madeearly so that it is available for every one ofthese processes.

Once the flow chart is made, there will beentries such as "make meal coated rice hulls"and "make stars". Each of those entries willhave sub entries, such as "weigh out chemi-cals", "screen them", etc. (Of course, theseentries can be dropped when one becomesmore experienced and is sure that theequipment is on hand). At this point thetypes and amounts of various pieces ofequipment and chemicals start to becomemore obvious. It can be seen that a balanceis needed, as well as cups or dishes to holdthe chemicals while weighing, screens, bowls,etc. Once those have been identified, it isgenerally the case that the expensive spe-cialty items come in singles (balances, ballmills, etc.), while the multiple items arecheap and relatively commonly available(cups, spoons, mixing bowls, etc.). It is agood idea to order the specialty items early,

since the project will be delayed until theyarrive. The cheap stuff from the supermarketcan be obtained at almost any time. Thatleaves the chemicals. One of the most com-mon questions that I get in e-mail is "Whatchemicals should I buy, how much of each,and from whom?".

The flow chart and the goals can help de-termine this. Let us take as an example aperson who wants to make round shells.They can use a spread-sheet program to helpdetermine what they will need. First, they

need to select a limited number of types ofstars and compositions. There will be BlackPowder for various purposes, as well as somecolor stars. The beginner should choose rela-tively simple stars, avoiding magnesiummetal and chlorates. The beginner shouldalso choose a limited number of stars, suchas red, white, blue, green, yellow, charcoaltail, blond streamer and perhaps one or twomore.

The left most column (called column A) willbe a listing of the names of each type of

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chemical, starting in about row 5 (rows 1through 4 will be used to label the columnsand other things). Then, the percentages forthe first composition chosen can be enteredinto column B. Thus, for Shimizu's Blue #2,the numbers would be 67 for potassium per-chlorate, 10 for red gum, 13 for black copperoxide, etc... Next, column C can be used tocalculate how much of each chemical willactually be needed. To calculate how much ofeach chemical will be needed, one has to es-timate the total amount that will be madebefore the next order. This is entered into cellC2 (column C, row 2). This weight can be

given in pounds, since the chemicals aregenerally ordered in pounds. Then theamount needed for each chemical is calcu-lated using a formula (all formulas are givenin Excel, but other systems are similar). Foreach cell, the formula is =(C2*B/100). Thus, if the potassium perchlo-rate is in row 5, then this formula would read=(C2*B5/100). In this case, if the userwanted to be able to eventually make 5pounds of Shimizu Blue #2, then this wouldcalculate that the user needed 3.35 poundsof potassium perchlorate just for these stars.

This process is repeated for each of the othercompositions - for example, the red stars canbe put in columns D and E, and the greenstars put in columns F and G, etc. Alwayskeep the percentages for potassium perchlo-rate in the same row (for example, row 5).Add new rows as needed for new chemicals.In this example, a new row would be neededfor strontium nitrate for the red stars, andanother one would be needed for bariumsalts for the green stars. However, do notmake new rows for old chemicals. In eachcase the first of the two columns will contain

the percentages, and the second column willcontain the amount needed calculated by aformula similar to the one given above.

When all of these numbers have been en-tered, then the total amount for each chemi-cal can be calculated in the next empty col-umn by summing up the individual needs foreach star type. Thus, if one was only makingblue, red and green (as above) then the for-mula for the total amount of potassium per-chlorate (remember that it is in row 5) wouldbe placed in cell H5, and would be

=C5+E5+G5. Of course, if columns H and Iwere used for yellow stars, then the totalwould be in J5, and so forth. This will givethe minimum necessary amount for eachchemical. Don't forget to round up when or-dering. Also note that most distributors giveprice breaks at 5 pounds and 10 pounds, soit might be cheaper to order one 10 poundpackage rather than a 5 pound and three 1pound packages.

If a person is especially ambitious they canthen utilize the spreadsheet to determinewho would give the lowest price on the entireorder. This entails entering the prices fromeach distributor's catalog, and using somesimple functions to figure out whose price isless. However, there may be a reason to splitthe order - for example, one dealer may bemore expensive on some items, and less ex-pensive on others. An alternative is to usethis to try to dicker - sometimes the dealersmight discount one or two items by a smallamount just to get all of your business and tomake you into a loyal and exclusive cus-tomer. Other times, they may just tell you togo get stuffed. I think it depends on a lot of

factors, including their current bank balance,phase of the moon, and mood of the spouse.The distributors can be found in the classi-fied ads in AFN.

One final hint - don't overlook the benefitsthat can arise from ordering in really largebulk. First of all, it can be the case that a 50pound drum or bag of some chemical mightonly cost about twice as much as a 10 poundpackage. That is because the suppliers don'thave to pay somebody to repackage it, andlabor costs aren't cheap. In addition, some

companies charge a lot of shipping fees, suchas UPS, Hazmat, etc. However, when the or-der gets big enough it may suddenly becomecost effective to ship by surface commoncarrier. While that may cost over a hundreddollars, this can be offset because there areno special box or hazmat fees to consider.And that shipping cost is for hundreds ofpounds, not tens of pounds. I have seen twoor three people pool their resources and buya quarter ton of chemicals, and the overallshipping costs were far below the normalcosts. TIP

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CUT STARSMy procedure for making 3/8" cut stars fol-lows: (All measurements are by weight.)

After star comp is mixed, I put one cup of themixture in a plastic bowl and wet down usinga spray bottle of water. I don't wet it toomuch - a half dozen sprays are all that isneeded. I then mix by hand until a doughyball is made. I know I have used the rightamount of water when the small amounts ofcomp that are stuck to the sides of the bowlstick in a doughy ball when pressed.

I built a star press frame by taking a 8x8x1"square piece of wood and then built a framearound it using 1 x 1/2" str ips of wood. I laythe frame down and put a piece of plastic sa-ran wrap over it, then put my wet ball ofcomp in the middle of the frame on top of theplastic wrap. I then spread out the comp withmy fingers as evenly as possible, then putanother piece of plastic wrap on top of thecomp. I take my 8x8x1" piece of wood andput it on top of the comp in the frame andpress down hard, then remove the block of

wood and the frame; what I'm left with is asolid slab of comp.

I remove the comp-slab from the plastic wrapand dust the comp with meal powder on bothsides. I let it sit for 10 minutes, then cut it

into cubes using a thin, but solid piece ofplastic. Then I separate the cubes, mist themwith water and roll them around in moremeal powder. I let them dry for 7 to 10 days.

USING THE STARS IN SMALL SHELLS

My shells are 2-inch plastic canisters using ahomemade visco time fuse. With black matchbeing difficult to obtain, I just pour my liftcharge down the mortar and install the shellso the reinforced fuse touches the lift charge.

A hole was drilled in the side of the mortarnear the bottom to accept the igniting fuse. Ichristened the skies this year on the 4th ofJuly. My breaks were fair, but my colors weregreat! Upon inspection of what was left of theshells, I found that just the tops were blow-ing off. My bursting charge was a mixture ofmeal powder and 4F. Back to the drawingboard.

All joking aside, I have found this un-dertaking to be one of the most infectious,stimulating and fascinating adventures I

have ever been on. I feel I have learned a lot,but at the same time I know I have justscratched the surface. You will be hearingfrom me again. If the pyro is ever needed,

just look up to th e skies, that 's where I willbe. GD

Potassium perchlorate

Potassium nitrate

Barium nitrate

Strontium nitrate

Shellac

Dextrin

Dechlorane

Black copper oxide

Charcoal - air float

Sodium oxalate

Antimony sulfide

Sulfur, flour

RED

6

6

1

1/2

2

GREEN

6

6

1

1/2

3

2

BLUE

12

1

5

3

2

YELLOW

8

3

2

1

2

1

WHITE

28

1

5

8

GOLDSTREAMER

8

1/2

1/2

4

2

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METHOD OF PRODUCTION OF MICRO STARSMicro stars are used in such items as gerbs,comets with crackling stars, and small bom-bettes. For a long time I have been searchingfor an appropriate production method foramateurs, without success.

I started my first attempt by drilling 3mmholes in Teflon plastic sheets of 3mm thick-ness. Then I placed the drilled sheets on aplain, smooth surface and started to paste aslightly wetted star composition into theholes, using a plastic spatula. I left it to dry

for a few days. I thought that when the starcomposition had dried the cylindrical microstars would be easy to remove. It did notwork at all. Nearly all the micro stars weredamaged when I pushed them out.

Another method I tried was to form a 3 mmlayer of wetted star composition and to cut itinto 3mm cubes, like cut stars. In general, itis difficult to get uniform cubes and, in mostcases, they stick together, especially if youuse nitrocellulose lacquer. Not a method tobe recommended.

For my next attempt I searched for a plasticmatrix, like a grid. Again I pasted my dampedstar composition into the matrix, thinkingthat after drying it would be easy to removemy cubes by bending the plastic, but thatwas just wishful thinking.

After some time, having already buried myidea of easy-to-make micro stars, I saw aplastic cutlery box in our kitchen. It was theshape of the grid-like spaces of the box thatcaught my eye. They had the form of little

quadratic, truncated pyramids with a 4.5mmedge length and 2.5mm height.

Again, using a plastic spatula, I pasted mydamped star composition into the matrix,which was then placed on a smooth plasticsurface. After having left it to dry for a sev-eral days, I bent the plastic matrix a little bitand - what a surprise - the little truncatedpyramids, my micro stars, jumped out. En-thusiastic about my success, I tried an NClacquer bound ("wetted") star composition.

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Even this star composition showed no ten-dency to remain in the matrix after drying,and after a short drying time I got my pyra-mid micro stars.

I hope I am not wrong if I say that the plasticis polyethylene.

This method is not suitable for large scaleproduction, but works very well for amateurmicro star production.

The photocopy above may give you an idea ofmy cutlery box matrix.

If you do take your wife's cutlery box, pleaseremember to buy her a new one! HWW

BARGAINS IN ODD PLACESLet me encourage every pyro to watch theirlocal newspapers for school district surplusequipment auctions. This is because old labequipment seldom attracts a lot of interestedbidders. This weekend I went to such anauction and got some real goodies for cheap!I paid $15 each for 5 lab benches, each 6'long with a thick chemical-resistant top.Each bench has 16 drawers for each individ-

ual student and a central cabinet for jointequipment. I paid $20 for a 6' by 3' rollingchemical demonstration table with a smallhand-pump sink and plastic waste recepta-cle. I also got a box full of ring stands, tri-pods, clamps, and assorted lab hardware for$2. The kitchenware sections provided somereal opportunities as well - stainless steelcounters with sinks, Hobart mixers, etc. Inthe past I have purchased a fume hood for$25(!) and various old balances at bargain-basement prices. TIP


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PILL BOX STARSMaking pill-box stars is really not that hard.Here is a simple way:

Rolling tubes: I use a 3/4" steel rod to roll on.Any type of material could be used, as longas the rod is smooth. I feel that the weight ofthe steel rod makes it easier to roll the tubes.

Paper: 65 or 70 lb. virgin Kraft, three turns.For a 3/4" rod, about 7 1/2" of paper will beneeded for three turns.

Manipulation: The paper is cut 20" wide and7 1/2" long, with the grain runnin g the 7 1/2" di-rection. Paste is applied to two-thirds of thepaper, which is then rolled around the rod,continuing into the pasted area. When com-pletely rolled, the tube is slipped off the rod.Some people paste the entire paper, includ-ing the area that touches the rod. That's ac-ceptable, but the rod can get tacky andwould need to be cleaned.

The composition is moistened with not morethan 8-9% 35/65 alcohol/water.

Match: A piece of flat blackmatch is cut toprot rude 1/2" from each side of the tube.

Assembly: The piece of blackmatch is placedinside the tube, protruding equally from bothends. The tube is then picked up andscooped into the moistened composition,which is then pressed with the finger andthumb on each end of the tube. This is con-

tinued until the tube is pressed full of com-position. The star loading may be finished byplacing the tube on a ramming tool and tap-ping lightly. Too much compression willcause the star to bu rn too long. LP

Drying tubes: The tubes should be allowedto dry slowly, not in the sun or oven as that

could cause them to wrinkle or curve. Whendry they may be cut to the desired length.

Composition: There are specific com-positions for pill-box stars. Many formulaswill burn too long in the tubes.

Pink & Silver Pill-Box Star


Strontium carbonate

Strontium nitrate

Red gum

Aluminum bright

Aluminum flake, small

Aluminum flake, med/lg

Dextrin

68%

14

2

6

4

3

3

+2

RED ILLUMINATING STAR

Strontium nitrate

American Darkaluminum #809German Pyroaluminum

Sulfur

PVC

Red gum or shellac

1

55

-

15

15

10

5

2

4

1

-

1

1/2

1/3

Notes:1) Dampen with alcohol. May be cut orpumped not much larger than 1/2" or pillbox.

2) Prime with hot prime like meal/silicon

JB

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As a side note, these aluminum Go Gettersdo not explode or burn all the way to theground like the ones made with magnesium.

Dave Johnson's book covers the constructionof Go Getter s in great detail so I will coveronly the highlights and differences.

THE TUBE

I use a standard 9/16" i.d. x l 1/2" long spiral-wound, machine-made tube with a 1/16"wall thickness, and standard 9/16" plugs.The end plugs do not need to be glued in asthe parlon, once it sets up, is quite hard and

will not blow the plug until the Go Getter isalmost done burning, if at all. The tubes arethen bundled into a convenient size package(I use bundles of nineteen) with rubber bandsand set on plastic film (Saran Wrap), readyfor filling. While Go Getters made with thesetubes go quite nicely, the tubes are still rela-tively heavy. One variation would be to tryhand-rolling some tubes from Kraft paperwith a thinner wall, to see if they fly better.Go Getters are end burners, so we shouldnot have to worry about blowing out thetube.

THE SOLVENT

A 90:10 mixture of dry acetone:xylene is usedas the solvent. Acetone is hygroscopic so it isimportant to use dry material. Fresh acetoneis best, but material of doubtful quality maybe dried in the following manner. A smallquantity (an ounce or so) of drying agent(calcium chloride or "Damp Rid" in Florida) isplaced in an acetone-proof plastic container,the acetone is added, the container is cappedand shaken to allow the drying agent to ab-

sorb the water. Care must be taken to releasethe pressure in the container by looseningthe cap/lid from time to time. Only a brieftime is needed to absorb the water and thenthe acetone is allowed to settle for a fewminutes. Lastly, the acetone is filtered to re-move any solids by pouring it through adouble layer of coffee filters; then it is storedin an air/moisture proof plastic containerand the drying agent is discarded (it's cheap).It is a good idea to dry only as much acetoneas is needed for the batch of Go Getters being

made. Caution is needed to remember thatacetone evaporates very quickly, the vaporsare heavier than air and extremely flamma-ble. Good ventilation and no sparks are amust.

The acetone/xylene solvent mix is added tothe composition in the squeeze bottle at therate of 33-38% by weight. Some experimen-tation may be necessary to get the properviscosity of the mix. The correct consistencyis somewhere around a slightly thickenedpancake batter (depends on your recipe). Af-ter placing the top on the squeeze bottle,about 25% of the air is squeezed out to allowfor expansion of the acetone vapor. Then agloved finger is held over the spout and thebottle is shaken vigorously for two to threeminutes or until everything is thoroughlyblended. Depending on the size of the batch,the operator may give the bottle a goodshaking every once in a while just to keepeverything in suspension, and the air mustbe squeezed out first. Then the tubes arefilled to the brim, ready for insertion of thefuse. It is a good idea to keep a toothpickhandy to unplug the nozzle, and some paper

towels to wipe the nozzle and the operator'shands.

THE FUSE (THE SECRET)

Black match or any other potassium nitrate-containing fuse cannot be used with alumi-num Go Getters like it can with the magne-sium varieties. This is because of the ammo-nium perchlorate and potassium nitrate re-acting to form the very hygroscopic alumi-num nitrate, which will quickly result in awet interface between the fuse and the com-position (believe me, I tried). The trick is to

use Thermolite. The Thermolite will not reactwith the composition, and it provides a nicehot flame to ignite the Go Getters. The Ther-molite is cut in pieces about an inch long,then as much of the fabric-wound outer layeris removed as possible. Then it is bent into anarrow U shape and inserted into the GoGetters, U end first, about half way, then laidover against the side of the tube. Once theslurry is poured, the Go Getters set upquickly, so the operator must prepare enoughfuses to complete the job. After the fuse is in

17


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serted, the tubes are set aside to dry on apiece of plastic wrap until no acetone odor isdetected, which should be 3 - 4 days. As theGo Getters dry, they will shrink back into thetube a little because one third of the slurry,by weight, evaporates.

By having two ends of the fuse exposed to theexpanding flame front with the shell, ignitionof the Go Getters is improved and more ini-tial thrust is generated due to the two pointsof ignition.

CONSTRUCTION OF A SIX-INCH ROUND

GO GETTER SHELLA round Go Getter shell is constructed muchlike any other ball shell of comparable size,with a few minor differences. The time fuse iscut to allow a delay of about 4% secondsbetween cross matching. A fuse extendermade from three turns of 30 lb. Kraft isrolled on a suitable former and pasted onlyon the last 1/4-inch or so of the trailing edge -

just enough to keep th e tu be from unrolling.The tube is then slipped over the cross-matched end of the time fuse and securelytaped in place (remember that at this time

only the end of the fuse that goes inside theshell is cross-matched). The fuse is glued intothe hemisphere and the fuse extender is cutoff so that it just reaches the center of theshell. The extender tube is filled with 4f andsealed against leakage with either a smallpiece of masking tape or pasted paper.

THE BURST

There are two theories behind the burstcharge for Go Getters shells. The first is touse a relatively hard burst to scatter the

stars and let them swim back toward eachother. Since the stars are placed randomly inthe shell, and they are not smart enough toknow which way to go, the result is a bigboom and Go Getters scattered all over thesky, with the distinct possibility that some ofthem will be driven toward the ground hardenough that they will not burn out beforeimpacting the earth. My preference is to usea soft break, only strong enough to open the

shell and light all the stars. Meal powder onrice hulls works well for this purpose. I use a5:1 ratio of meal to hulls, up to 6-inches, and4:1 for larger shells. Remember, they are self-propelled stars and don't need to be blown allover the place.

PUTTING IT ALL TOGETHER

Two pieces of tissue paper are cut to a sizesufficient to line the hemispheres withenough left over to fold across the top of eachshell half to hold the contents in the halveswhile assembling the shell. A hole is piercedin one piece of tissue and the tissue is in-

serted over the time fuse and smoothed outagainst the inner wall of the hemisphere. Thesecond piece of tissue is placed in the otherhalf in a similar manner except for the holefor the time fuse. The Go Getters are thenplaced against the inner wall of the shellabout half way up the wall. Care must be ex-ercised not to obscure any of the fuses.

Now burst is poured in to fill all of the crev-ices between the Go Getters. At this point,

just enough burst is use d to fill the crevicesand leave a thin layer over the already placed

stars. Stars and burst are added in alternat-ing layers until the hemisphere is full. Burstmust be forced into the crevices between theGo Getters as this is the only way to ensureshell integrity. The extra tissue that has beenhanging over the edge of the shell and gettingin the way is now folded toward the center ofthe shell, secured with a couple of pieces ofmasking tape. The other shell half is finishedin the same manner and the two halves are

joined us ing typical shell glue.

As was discussed earlier, Go Getter shells donot need a hard break. Consequently they donot need to be endlessly pasted with tape orpaper strips. My preference is to use two lay-ers of filament (strapping) tape on the 6-inchplastic shells. Paper hemispheres probablyneed three to five layers of pasted paper. Af-ter taping or pasting, the shell is finished inthe normal manner with the final crossmatch, lift and leader. JWD

18


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TESTINGWe get a small, but constant flow of ques-tions from people who are having variousproblems with stars they are making. Per-haps the most common one is the problem ofstars being "blown blind". That is, when ashell explodes in the air, some or all of thestars are not igniting. I don't want to go intoall of the diagnoses and solutions to thisproblem. They are discussed in detail in BillOfca's book, called "Ignition: Materials,Problems & Solutions".

Over and over I hear from people who are notadequately testing their stars before they areassembled into a fireworks device. Almosteveryone will test burn his or her stars in astatic situation, that is, while the star is sit-ting still. But an amazing number of folksnever test fire their stars out of a star gun tosee how they will perform in the air.

Now a star gun can be just about any make-shift mortar or tube. You can use a simplecardboard tube with just enough clearancefor the star to fall down into it freely. Just

plug one end of the tube, and drill a fuse holeright above the plug. Stick a piece of Viscointo the hole, drop a pinch of black powderinto the tube, and then a star. Light the fuse,get back and watch what happens. If yourstar does light, you will be able to see apretty good approximation of how it will per-form in a shell or a mine.

If your s tar doesn't light, you may have oneor more problems. You may have put toomuch lift powder under your star, propelling

the star so fast that the flame actually blowsout. Test another star with less powder andsee if it ignites. Remember, if the star is aclose fit to the firing tube, then it will onlytake a very small pinch of powder. If the starstill does not light, even with a smalleramount of lift powder, your problem is likelypriming. Either the star is not primed or theprime you are using is not hot enough tolight the star composition. Again, I refer youto Bill Ofca's book for more details on prim-ing solutions.

STARSSimple, cardboard-tube star guns are cheap,but they have the drawbacks that one-size-does-not-fit-all-stars, and that they eventu-ally burn up and come apart so you have tokeep making new ones. At one point in mypyro career I actually had time to make a lotof stars. I had my friend John Smith in Bal-timore make me up a star gun out of steelwith five, different-sized barrels: inside di-ameter s of about 3/8 ", 1/2" 9/16", 3/4" and 1-1/16". He welded the guns in a straight linevertically onto a flat steel plate, drilled Visco

holes in the base of each gun, and even spraypainted the whole thing flat black. Neateststar gun I have ever had. It doesn't wear out.The different inside diameters of the tubes letme shoot any sized star I made using almostno lift powder. In fact, I can shoot them sosilently that my next-door neighbors can'teven hear a thing when it fires. HG

KITCHEN PYRO -AT VULCAN'S FORGE

I had obtained some -100 mesh iron powderto use in making sparkle rs. As a test, Idropped a few iron grains into the flame ofthe kitchen stove.

What occurred was a group of bright orange"slivers" of light - none of the desiredbranched sparks.

On a hunch, I looked up an entry by TakeoShimizu in Lancaster's 1972 Fireworks Prin-cipals & Practice (page 228). He sta tes tha t

pure iron sparks don't branch, but alloyswith up to 7% carbon do.

In a creative mood (especially since my wifewas out and wouldn't see me tossing noxiousmaterials on the stove) I rubbed a littlegraphi te into some iron powder. When someof the mix was put in the flame, bingo: mul-tiples of branched orange sparks.

Unfortunately, graphite did not improve thedull spar ks of ferro-aluminum. FJ

19


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BRILLIANT ILLUMINATING SILVER ELECTRIC NON-SIZZLING

RED COMET SHOWER STARSTraditional red/silver stars have beenmade with potassium perchlorate/stron-tium carbonate/fuel/aluminum, and suchformulations are given by Ron Lancaster(Fireworks Principles & Practice, p.92),among others. I find this kind of star verydisappointing because the amount ofaluminum required for a good show ofsparks invariably harms the color, so thatonly pink is obtained. Ken Kosanke hassugge sted two alternativ es, bo th of whichare markedly superior to the use of alumi-num. One uses coarse atomized magne-sium (Sizzling Colored Comets, AFN No.63)and the other uses coarse titanium (TheUse of Titanium in Pyrotechnics, PGI Bulle-tin No.67). These articles also list equiva-lent formulations for blue and other colors.

The effects of the magnesium and titaniumare substantially different from each other,the latter producing longer lasting sparks

which are slightly yellowish. Thered/titanium formulation has no chlorinedonor and is therefore not truly red, butrather deep pink like the parentKClO4/SrCO3/fuel systems. My own pref-erence is to use a fairly pale pink when Iwant pink, and red when I want red. Thisavoids confusion. Whenever I see a deeppink I am always left wondering whether itwas supposed to be that way or whether itwas intended to be red and didn't quitemake it. The red effect can be obtained byfollowing Joel Baechle's suggestion (Pyro-color Harmony, p.12) of adding 10% tita-nium to Sam Bases' ammonium perchlo-rate red star #15.

I like to have a greater profusion of longlasting sparks than is allowed by thesekinds of compositions, without spoiling thebalance and contrast between the headand the tail. One solution is to use a bril-liant (illuminating) type of star which cantolerate a greater amount of titanium,

while maintaining good color and contrast.Such a solution is given for green by KenKosanke in his titanium article and I offerhere my red, which is formulated alongsimilar lines.

Brilliant Red/Titanium Star

Strontium nitrate

Titanium (10-20 mesh flake or10-40 mesh sponge)Magnesium (granular 40 mesh)Polyvinyl chloride

Polyvinyl acetate


(Dampen with isoamyl acetate)

40

20

1515

5

5

It is not necessary to coat the magnesiumwith linseed oil as the polyvinyl acetatebinder provides adequate protection, andthe stars can be kept for years without anysign of decomposition or decrease of per-formance. The stars are fast burning andcan be fired from the ground, as in Romancandles, etc., as well as aerial effects. Thesame composition is also excellent forhanging cases for waterfall effects. Suchthin-walled cases containing the PVA-bound composition have functioned per-fectly after hanging overnight in the rain. Iprefer to use PVA for binding because Ifind it easier to handle, but parlon devo-tees could no doubt adapt the formulation.

Returning briefly to the blues mentionedearlier: The potassium perchlorate formu-lations given by Ken Kosanke are service-able but not sufficiently deep for my pur-poses. I prefer the approach of Dave Bleser(AFN No.66), adding ferrotitanium to anammonium perchlorate blue star in asimilar way for a long, bright tail, and aslittle as 5% titanium can be highly effectivewhile maintaining excellence of color.Magnesium should not be added to anammonium perchlorate blue compositionbeca use of incompatibilities.

20


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Addendum

A solution of polyvinyl acetate (PVA) in vari-ous solvents is sold as glue, particularly inEurope. Pyrotechnists have told me of theirsuccess in using solvents other than isoamylacetate [banana oil] for PVA binding, but Ihave no experience in this and so refrainfrom comment. What I had in mind in refer-ring to parlon was to replace the combinedPVA and PVC contents with 20% parlon,utilizing its binding properties by means ofacetone, butanone (MEK), or other suitablesolvents. Again, this is speculation to be real-ized by the interested reader.

Many pyrotechnists have a legitimate con-cern over the very high corrosion potential ofmagnesium. The use of PVA or parlon forbinding effectively coats the magnesium par-ticles with plastic, thereby preventing de-composition. An alternative solution, which Ihave recently adopted, is to replace the mag-nesium with a high magnesium contentmagnalium, which allows the use of moreconventional binding techniques withoutcausing corrosion problems.

Here is an alternative formulation:

Brilliant Red/Titanium Star

Strontium nitrateTitanium (e.g., 20-40 mesh)

Magnalium (65:35, atomized 150 mesh)

Polyvinyl chloride

Accroides ResinPotassium perchlorate(Dampen with alcohol)

40

20

15

15

55

Stanbridge (Pyrotechnica XVII, 1997) has

suggested that the designation AccroidesResin as commonly used by pyrotechnistsmay be incorrect. I have no expertise in thismatter and have no reason to doubt Stan-bridge's assertion. The material I favor forbinding here is a medium grade sold bySigma Chemical Co. labeled as "Gum Accroi-des". It gives the appearance of being essen-tially identical to material sold by pyrotechnicsupply companies labeled as "AccroidesResin" [Red gum]. Finer material does notmix as easily, and coarse material generallycontains extraneo us matter. CJ-W

SIFT THOSE CHEMICALSHow many of you pyrophiles just assumethat a 5 lb. lot of chemical XYZ is ready touse when it arrives from your supplier? Iused to, until one day when I noticed a sig-nificant amount of debris was failing to passthrough my 40 mesh star comp sieve. Afterisolating the offending culprit, I decided tosift the material all by itself. I was quiteamazed at the volume of "stuff that was re-moved by this process.

Repeating the procedure on various other

chemicals yielded similar results. Organicresins seem to be particularly prone to thistype of contamination. Following is a list ofchemicals I've experienced this problem with,including the identity of some of the materialremoved:

21

I'm sure there are others which could be in-cluded. The point of this discussion is to alertthe pyrotechnist to a potential source of inef-ficiency in their efforts to perfect their formu-lations. The weights alone of these con-taminants may alter the constituent ratio insome color formulas and hence adversely af-fect the color. Even if this does not occur, Icertainly don't need sticks, leaves, grit, etc.

in my mix when I'm trying to cut or roll stars!

The solution is to sift chemicals individuallybefore storing for future use. This way I knowmy composition percentages are true and willundoubtedly enjoy the pride of improved for-mulations. LC

Red gum: leaves, sticks, sand.

Sulfur: unground crystals.

Charcoal: unground particles, sand.

Aluminum: flakes way out of mesh range.

Parlon/Strontium carbonate: unground

particles out of mesh range.Shellac: sand, unground particles.


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PRIMING COMET SHELLSTo get the best effect from an Italian canister-style comet shell, the diligent pyro strives fora somewhat harder break than the usual cy-lindrical star shell. With fewer effect "units"in the comet shell and each "unit" beinglarger and burning longer, wider separationof the stars results in an enhanced effect.

The ferocity of "brisance" [pronounced bre-z'ance; Ellern definition: ability of an explo-sive to shatter its solid confines or surround-ings] of the overall shell burst is a pressure

phenomenon adjus table on two fronts: 1. de-gree of containment and 2. strength or bri-sance of the burst charge. Observing the dif-ferences between Oriental ball and Italo-American canister break patterns readily il-lustrates the interplay of these two factors.

Fulcanelli1 describes the variation sometimesused for spiking comet shells "...a closerpattern is occasionally used; typically thenumber of side strings employed is increasedto that normally used on the next larger sizeof shell. For example, a 5" comet shell mightbe spiked with 32 side strings (the patternordinarily used for a 6" shell) instead of 24.Circumferential spiking is also closer, tomatch the closer vertical spiking, makingsmall squares on the side walls." This tighterpattern is meant to increase containmentand hence burst pressure and diameter(factor #1). Some builders seek to increaseburst radius by using "hotter" (read faster ormore brisant) break charges. Indeed, "slow"flash powders and their various combina-tions are sometimes employed (factor #2).

Often the successful achievement of a widerburst pattern introduces the frustratingproblem of poor star ignition. In actuality,ignition is enhanced since increased con-tainment and/or more brisant burst compsboth result in higher intrashell pressure andsubsequently higher temperature as perphysical gas laws. The real problem involvescritical wind velocity. Even though the com-ets are lighting well initially, they begin to fallupon shell rupture as they are propelled inopen air at such speed the flame front is

stripped away from the reacting surface.

What good is a horizon-to-horizon break ifmost (or all) of the comets are blown blind?This problem usually occurs within the firstfew milliseconds after case rupture; if thecomet can be engineered to stay lit duringthis interval, the flame front can "catch up"as the comet decelerates. Cut or rolled starsare easily primed by rolling them in the igni-tion comp of choice until a sufficient layer isachieved. Priming comets in this fashion,however, is usually impractical since thecomet diameter increase due to prime build-

up multiplied by the number of comets in aring usually disrupts the fit around the innershell periphery.

A simple technique was developed by whichpriming is effected after the comets havebeen loaded into the shell casing. After allcomet rings have been properly loaded (eachring being staggered in brick-house fashionatop adjacent rings and tightly sawdusted or"rough powdered" in) the shell is up-endedand gently tapped to remove excess sawdustor polverone. Thick nitrocellulose lacquer is

painted over the inner cylindrical surface ofthe comet charge facing the burst core usinga narrow paint brush. Immediately followingthe painting, a generous scoop of primingcomp is dumped into the shell and the entireunit is rotated in barrel fashion until the wetN.C. layer has picked up all it can take(alternately, after adding the prime, the openend of the shell can be covered and the wholething shaken to distribute the prime). All ex-cess prime is dumped back out of the casingand the shell is left to dry completely(preferably outside due to the acetone vapor).

Upon drying the burst charge is introducedand the shell is finished in the usual fashion.

It should be obvious to the reader that thismethod is only feasible for use with raw, un-covered comets. It cannot be used with pa-pered comets (i.e. crossettes or color-changing cavity comets) since burn-throughof the paper covering would occur, thusspoiling the effect. Nevertheless, the authorhas found it to be an excellent method of en-suring ignition and he currently employs it

on all unpapered comet shells regardless of

22


25/212

composition. Even colored comets can besuccessfully fired using this technique.

Two points of some importance deserve men-tion before concluding. First, the N.C. lac-quer employed in this technique should bethick, about the same viscosity as cane mo-lasses, so it will stick where it is painted,without runs or sags. As reported by Hymanin Cardwell's review2, the author compoundshis own N.C. lacquer using rifle or shotgungrade smokeless powder and dry acetone.Single-base nitrocellulose powders work best,such as Accurate brands 2015 BR, 2495BR, 3100, 4350, Solo 1000, and Solo 1250.Avoid Winchester and Alliant (formerlyHercules) brand powders as they are alldouble-base, nitroglycerine-containing prod-ucts. The powder granules are mixed withacetone in a 1:9 (10%) or 1:10 (9%) ratio andallowed to stand in a tightly capped jar forseveral days with occasional shaking. The re-sultant product is a thick, black liquid (blackcolor probably due to the graphite coating)with a slight yellowish-green cast, which isexcellent for many pyrotechnic applications.A very inexpensive source of smokeless pow-der for N.C. lacquer was recently discoveredin the Class "C" products "Great Balls of Fire"and "Dragon's Breath". The pellets from thesetwo devices make a good quality N.C. lacquerwhen mixed in a one ounce to one pint ratiowith acetone.

Lastly, the priming powder used in thismethod should be granulated in the 4FA to2Fg range. These granules are small enoughto thoroughly coat the wet N.C. lacquer yetlarge enough to provide a rough, highly ignit-able surface. A good quality ball-milled Black

Powder mix that's been granulated throughan 18 mesh window screen and dried workswell.

References1) Fulcanelli, A. 1984. Traditional Cylinder ShellProduction - Part 1, Issue IX, Pyrotechnica: Oc-casional Papers in Pyrotechnics, Austin, Texas.

2) Cardwell, Robert G. 1979. Strobe Light Pyro-technic Compositions: A Review of Their Develop-ment and Use. Issue V, Pyrotechnica: OccasionalPapers in Pyrotechnics, Austin, Texas. LC

WATER BOTTLE SALUTEWhile attending the Science Teachers confer-ence last month I learned how to make a waterbottle salute that makes plenty of noise but nosmoke or physical damage.

To make one, a regular 16.9 fluid ounce waterbottle (Deer Park, Zephyrhills, or any localbrand) is filled with water, then with the capon, inverted into a deep tray or shallow basinfilled with water (which is what chemists call a"pneumatic trough"). After removing the capfrom the inverted bottle, hydrogen gas is bub-bled in with a rubber hose, until the bottle isabout two-thirds filled with gas (which will dis-place the water from the bottle).

Hydrogen can, of course, be made very easilyby adding small pieces of zinc metal to dilutedhydrochloric or "muriatic" acid.

Then the hydrogen hose is removed and re-placed with one carrying oxygen gas. (I makeoxygen by adding the catalyst manganese diox-ide to ordinary 3% hydrogen peroxide solution.)The bottle is filled the rest of the way with oxy-gen and then the cap is put back on while the

bottle is still in an inverted position. The waterbottle salute is now ready to fire (and will be aslong as the cap is left on).

When I do this in front of my class, I fasten thebottle to a ring stand with several heavy-dutyrubber bands so it won't jump around from therecoil effect. Then I remove the cap and placemy hand over the bottle to hold in the hydrogen(which otherwise would rise upward because itis lighter than air). I then tell the students toprepare themselves, quickly remove my handfrom the mouth of the bottle and immediatelybring a lighted "Aim 'N' Flame" long-handledbutane lighter to the top of the bottle.

It takes a fraction of a second for the explosionto occur (since the rising hydrogen has to reachthe flame). There is a quick burst of mostly blueflame, and a very loud, sharp report that reallystartles the students. There is no smoke be-cause the reaction product is only water vapor.

The only damage that ever occurs is that thebottom of the bottle is sometimes bulged out-ward a bit. ST

23


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NEW FORMULAS FOR COLORED SPARKLERSAs the school year drew to a close and July4 th approached, the students in my advancedplacement chemistry class wanted to know ifit would be possible to make fireworks as aspecial end-of-the-year project. Of course Iagreed, but with the provision that our pyro-technic endeavors be limited to legal fire-works designed to produce sparks and color,rather than audible effects.

I immediately recalled the instructions for"steel sparklers" given in the late Dave Kel-

sey's Amateur Pyrotechnics booklet. The for-mula given by Kelsey worked fine, and pro-duced a white flame and long-lasting orangesparks. The logical next step was to makeflames of different colors, but this proved tobe somewhat more difficult than anticipated.

The only formulas for colored sparklers that Iwas able to find in print were for "ruby & em-erald shower sticks" in Weingart's Pyrotech-nics. Unfortunately, the formulas seemed abit too unstable to deal with in a publicschool science laboratory. (The green formula

calls for a combination of barium chlorateand aluminum powder.) So, it appeared thatI would have to create my own color mixturesif my students were to produce safe and ef-fective colored sparklers.

The first step was to substitute barium ni-trate for the more dangerous chlorate. I alsorealized that replacing the aluminum pow-ders with magnalium would improve the col-ors without significantly increasing the sen-sitivity of the compositions. I then startedthinking about possible color intensifiers,and recalled the Parlon/magnalium coloredstar formulas I'd seen. Some of those formu-las include sulfur, so I decided to add sometoo, to aid in ignition. (Sparklers, needless tosay, are notoriously difficult to light with amatch or lighter.) Finally, I chose to use thewheat paste called for in Kelsey's formula asa binder, rather than the more hygroscopicdextrin included in the star compositions.Here are the formulas I came up with after alittle experimentation.


Strontium nitrate

Barium nitrateMagnalium,-100 mesh, 50/50Sulfur

Wheat paste(wallpaper paste)

Parlon

RED

2

20

208

66

4

GREEN

2

8

6

6

4

Each ingredient was ground separately in a

mortar and pestle, and then mixed togetherwith a spatula on waxed paper. Water wasthen added, a little at a time, with continu-ous stirring, until the mixture became a thickpaste. It was found to take about 40 ml ofwater for each 46-gram batch of composition.

The paste was coated on bamboo "shis-ka-bob" skewers which had been purchased at alocal supermarket at $2.69 per 100. It tooktwo separate coats to get the layer of com-position thick enough to make an effectivesparkler. The sparklers were dried in an up-

right position by inserting their bare endsinto foam blocks of the sort used for flowerarrangements, and then drying them in ourschool's drying oven at 120F. for 72 hours.

We lit the sparklers immediately after remov-ing them from the oven, which probably ex-plains why the red sparklers ignited easily inthe humid summer climate despite strontiumnitrate's well-known hygroscopicity.

My students and I were both greatly im-pressed by the performance of our creations.

They burned with bright, true colors, whileemitting small white sparks. The colors weresuperior to anything I've seen in sparklersbefore, an impression that my studentsseemed to share. In fact, they reported thatour sparklers "put the bought ones toshame".

I feel certain that my chemistry students willnever forget the flame-test colors for stron-tium and barium. ST

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COLORED SPARKLER

UPDATEIn my article, New Formulas for ColoredSparklers I gave formulations using -100mesh magnalium.

When I recently tried to replenish my supplyI could not find -100 mesh magnalium at areasonable price, so I bought -200 mesh

powder. Anticipating that this change wouldradically alter the performance, I experi-

mented with the formulation and found thatif the potassium perchlorate is omitted, the-200 magnalium produces a sparkler thathas colors that are probably even better thanthe ones I made before.

Everything else is the same; I just sub-stituted the -200 mesh for the -100, andomitted the potass ium perchlorate. ST

SUPER SILVER FOUNTAIN

Lancaster Silver FountainPotassium nitrate

Barium nitrate

Meal powder

Aluminum*

5

455

45Lancaster cautions that the aluminum is criticaland suggests a mix of mesh and type. One mixmight be:Aluminum, dark pyro

Aluminum, 80-120 mesh

Aluminum, flitter, 10-30 mesh

15

15

15

I wanted to experiment with the LancasterSilver Fountain last night, but when I wentto make the comp., I had no aluminum flit-ter, so I substituted aluminum firefly, whichis about the same mesh size. I loaded thecomp. into a 7 1/2" x 3/4" i.d. rocket motor casingwith no throat and a bentonite plug. Then,remembering reported ignition problems, putsome blue star mix on top to get it started. Iviscoed it and called the family out to watch.The blue comp. fired, but the aluminumcomp. didn't. It was cold, and the grumblingfrom the audience about "duds" and

"amateurs" was starting to reach my ears. Itold them to wait and then quickly went backto my lab.

By that time the fountain top had cooled, so Iput four small bits of thermolite fuse on topof the aluminum comp., then found somefountain base mix which I poured into thetop of the cooled casing to a depth of one-halfinch. I quickly ran back to the front of thehouse, which by now was, of course, emptyof spectators, they having retired to thewarmth of the family room fire.

Unchoked Super Si lver FountainAmmonium perchlorate

Hexamine

Stearic Acid

Steel Powder orTitanium filing

Copper carbonate orBarium carbonate orStrontium carbonate(optionally added for color)

65

107

12

6

Undeterred, your intrepid pyro stuck in a

piece of visco, lit it, and it worked great! Thefountain base comp. caught easily, which litthe thermolite, which burns at a high tem-perature. That lit the comp. with no trouble -

just a momentary die down between thecomps. The unchoked fountain attained aheight of about 15 feet, and ended with agreat light and brilliant white flare - a trulyspectacular "bang for the buck" for 100 gms.of comp! My appreciative audience witnessedall through the window, with only vaguemutterings of "it's about time" and "whydidn't it work the first time?"

Actually, this is a variation of a step-wiseprime, although the above has the advantageof being a specific answer, as well as beingtried and true. It's just to ram half an inch offountain base comp. in first, after figuringwhat color, if any, is wanted to start thefountain (hence the Cu/Ba/Sr carbonateadd-in), then the rest is rammed with theLancaster Silver Fountain comp. I am goingto try this with a choked version and see howit works. This is one super fountain for verylittle effort. WWG

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LIGHTNING BOLTSOne of the questions people ask is "What aresome projects that are quick and easy?". Thisis important if one is trying to enthuse be-ginners who don't have the skill or confi-dence to make complicated devices. A fewsimpler projects can often launch them downthe road to pyro-addiction.

One surprisingly simple yet effective projectis the construction of "lightning bolts". Thesecan take many forms. The simplest form usesmasking tape, a bit of visco, commercial or

good-quality homemade Black Powder andsome coarse metal or broken bits of stars.

First, the pyrotechnic composition is made bymixing granulated metal with a good BlackPowder. Commercial 3Fg works great, al-though a good homemade BP will work. Theamount of metal isn't critical - I've seenlightning bolts work with as little as 5% or asmuch as 25% (by weight) of metal. The metalcan be any one of the common spark metals,such as iron, titanium, zirconium, alumi-num, etc. Don't forget that anyone can get

bags full of free iron turnings from localbrake shops. These can be treated with alight spray of WD-40 to help them last a littlelonger in the presence of the potassium ni-trate and sulfur. However, this is a lightcoating and these lightning bolts may notlast for more than a few weeks, especially ina humid climate. The Black Powder can alsobe loaded with bits of broken stars.

Next, about 2' to 6' of masking tape is laid onthe bench, sticky side up. The width is not

critical, but 1" works pretty well. Tape whichis wider than 1" works better than tapewhich is narrower. A 3" to 4" bit of visco islaid across the tape about 1-inch in from oneof the ends, leaving from 2" to 3" exposed onone side. Then, a plastic spoon is used todrizzle a line of pyrotechnic compositiondown the length of the tape. This line shouldbe about half as wide as the tape, and itshould NOT be allowed to reach the edge ofthe tape. Then, another piece of tape isplaced sticky-side down, capturing the viscoand the pyrotechnic composition. This com-

pletes the lightning bolt. Basically, this issimilar to metal-loaded Sticky Match, exceptthe tape seals from side to side and there areno overhanging sticky edges.

This is then hung from a stick, a bit of wire,or draped over a fence, and the visco is lit.One must be very careful NOT to allow thefire to get near the lightning bolt, as the sealis not perfect, and small fire leaks may existalong the edges. When the visco hits the BPcore it acts like weak-walled quickmatch. The

fire flashes from end to end, blowing open thetape and sending a shower of sparks up toten feet in all directions. Not bad for a fewteaspoons of BP and a few grams of metalgranules!!!!

After the lightning bolt is fired, the maskingtape generally proceeds to burn, creating asmudgy black smoke and leaving carbonsmudges on the ground. Thus, some peoplemight find the use of thin paper tape to bepreferable! In this case some 1" wide (orwider) gummed Kraft tape can be laid on the

table with the unwetted glue upwards, thevisco placed and the powder train laid downas before. Then, the top layer of tape can bewetted, and pressed sticky-side down overthe lower tape. This makes an instantquickmatch. Unlike the masking tape, thishas to be allowed to dry for an hour or twobefore use. But it doesn't tend to burn as of-ten, and the fire is less obnoxious if it doescatch on fire. TIP

PAPER PLUGSWhen you're all out of particular cardboardplug you need, here's a fix. If ju st a few areneeded, they are easy to make. I just cut cir-cles of thick paper about the thickness of amanila folder, and then, using a dowel orrod, shove them into a hole drilled in a pieceof wood. They may not be as pretty as store-bought plugs, but they definitely tide me overwhile I'm twiddling my thumbs waiting formy pyro supplier to get the ones I need backin stock. HG

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SAFETY ISSUES CLOUDI am writing today about a couple of safetyissues that would interest many of our read-ers. This relates to two experiences I hadwhile making Black Powder.

At least one author recommends using a 12cup glass coffee urn, such as the type thatcomes with coffee machines (e.g. Mr. Coffee),to make Black Powder using the CIA precipi-tation method. I had an urn crack and splitwhile gently heating it, nearly dumping theentire contents on a hot electric plate, which

would certainly have made a horrible mess atthe very least, not to mention the possibilityof ignition once enough water had beendriven out of the mixture. I then checkedevery manufacturer of coffee machines aswell as replacement urns and they specifi-cally warn against using the urns on a gasstove or electric heating element. The glass isnot Pyrex and is not heat resistant. Stainlesssteel or glass cookware or a Teflon coatedaluminum pan would be a better choice. Noaluminum would be exposed to the nitratebecause of the coating, and would be unlikely

to react significantly because it is solid andnot finely divided as in powdered aluminum.A plastic or wooden spoon should be used tostir the mixture, of course.

Secondly, I discovered that a stainless steel

Pyrotechnists as a group have always beenincorrigible recyclers. Long before environ-

mentalism became trendy and politically cor-rect, pyros were making the most of cast-offmaterials. For example, John Babington re-lated in his 1635 book, Pyrotechnia, that forthe cases of rockets "you must provide somegood strong paper, as old Law books, whichare both strong and large". We always sus-pected there must be some constructive usefor those stifling, mammoth volumes of ver-biage.

Given our historical ties to the recyclingmovement, it is only fitting that the recyclers

KITCHEN UTENSIL USEbowl will get hot enough to ignite Black Pow-der when set in the sun. The semi-parabolicshape of the bowl can focus the sun's rayswhich, combined with the heat retainingproperties of black objects, could be enoughto heat the powder to over 350C. and causeignition. This happened in early April -imagine if it had been July! Nowhere in myreading have I found recommendationsagainst leaving Black Powder in the sun incontact with metal. You can bet that thisreader will not make that mistake again!

MKDB

ADDITIONAL INFORMATION ON

ABOVE: I had difficulty believing that astainless steel bowl full of meal powder couldreach an ignition temperature of 350C.

Tenny L. Davis [Chemistry of Powder & Ex-plosives] states that 4F Black Powder takesfire at 190C, 5C. The reason for the muchlower temperature, and hence, activation en-ergy is sulfur's great tendency to attract

electrons and form free radicals. Sulfur is thereason Black Powder is so sensitive to elec-trostatic discharge (ESD).

A temperature of 190C could credibly bereached in a shiny semi-parabolic stainlesssteel bowl of Black Powder, sitting in the sun.

MKDB

should contribute something for the pyrosnow and then. The latest innovation from

their business that I have appropriated forpyro use is a handy little press commonlyknown as a can-crusher. The can-crusher isan inexpensive press that is designed to bemounted with screws onto a wall or shelf inthe kitchen where normal persons use it ex-clusively for the purpose of crushing alumi-num cans. Said cans can then be stored in amuch smaller space than their uncrushedcounterparts.

The first time I ever saw a can crusher waswhen I moved to Missouri, one of the states

POLITICALLY CORRECT PYRO TOOL - THE CAN-CRUSHER

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that has no can return law. Here in Missouriwe crush the cans and save them up until we

get a few bags full. Then we either take themdown to the recycling center and sell themfor cash or alternatively, we might mill themdown into aluminum powder. [More on thissubject will be revealed later.] When I in-stalled my crusher, my first impression wasthat it resembled my arbor press the one Ihad sometimes used to press experimentalrocket motors. A ha nd lever on a simplehinge mechanism moves two horizontally op-posed plates together with considerable force the mechanical advantage of my press is

about 3:1. Now, that is not sufficient for

Having experimented quite a lot with conesover the years, I've had several rethinksabout them. [See page 20, Best of AFN III forthe author's previous work with cones.]

One rethink is the issue: buy versus build.And here I'm not talking about the completeanimal but about the cone cases.

In my first cone experiments, I literally rolledmy own. After finding or making suitableformers, I made my own cone cases fromsemi-circles of Kraft paper. The process wassomewhat tedious. So I was delighted when Ifound that my sister, who worked for a textilemanufacturer, could buy good textile conesfor me cheaply. And cheap they were, only afew cents each.

With a cheap supply of textile cones, I startedto forget about rolling my own. But recently

I've gone full circle when I discovered howmuch a local hobby shop is asking for them.At those prices one can almost buy a fire-works cone, complete with its pyrotechnicmaterials! So maybe it's back to rolling myown (or looking for another cheap supplier oftextile cones).

I used to be fanatical about preventing thecone tips from burning, so I filled the ends ofmy cones with Plaster of Paris, shaped intosuitable nozzles. These worked OK with asmall amount of pyrotechnic material, but

many pyro applications.

Moreover, the plates have only about 5%inches of clearance between them -- notenough for most tooling. Yet I discovered thatthe can-crusher had sufficient clearance touse my 4 oz. screaming rocket tooling, aswell as sufficient pressure to consolidate myold favorite "red rocket mix" in small cases. Iam certain the device would work for someother applications. The can-crusher has theadditional advantage of sitting unobtrusivelyand patiently in one's kitchen or garage, allthe while doubling as a politically correct re-

cycling tool between pyro uses . WK

got clogged if the material burned longerthan a certain time. An adverse side effectwas the cone walls under the nozzle burningthrough. So I finally went back to the methodof dipping the cone tips in sodium silicate(water glass). Note that sodium silicateshould not be confused with sodium salicy-late which is used in whistle compositions.

I had some bad experiences with the bottomplug being blown out shortly after the conewas lit. To get around this problem, I optedfor a complex plug consisting of four pieces ofcardboard, two thick and two thin. This wasa real overkill. Eventually I found the bestsolution to be one piece of really stiff card-board. Here I found that the cardboard fromthe covers of three-ring binders worked thebest. I cut circles from this stiff cardboardwith a modeling knife. I then pressed onecircle into the bottom of each cone and ran abead of Elmers glue along its circumference.

This method worked well with normal conecompositions, without any blowouts. But onetends to forget just how much pressure canbuild up inside a cone. I made the mistakeone day of mixing in some left-over powderfrom some magnesium stars in the cone mix.This was just a bit too violent for the other-wise sturdy plug and it popped out with aload bang, sending the rest of the cone intoorbit. IvM

CONES REVISITED

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BLACK POWDER BURN RATES - APPLES & PEARSI remember how elated I was with my BlackPowder burn rate test results. My latestbatch of homemade Black Powder had justclocked in at a burn rate of 105 cm/second.

It was round about midday and my BlackPowder had been drying out in the sun sinceearly that morning. I had decided to do pre-liminary tests before the stuff had driedcompletely. The results far exceeded my ex-pectations. I then left the rest of the batch ofBlack Powder to sun dry for the rest of the

afternoon. I had decided to do a second teston the completely dried Black Powder. Thesetest results were even more surprising.

I ran the second test late that afternoon; theburn rate: barely 70cm/sec.! Something waswrong, but what? I ran some more tests andachieved burn rates varying between 60 and85 cm/second. Why the discrepancies? Andwhy were none of the results close to the 105cm/second test?

I then tested another batch of Black Powder

which I had made a couple of months before.My original tests had consistently measuredburn rates of about 90 cm/second. The latesttest clocked a slightly slower rate but stillclose to 90 cm/second. Now I had a realmystery on my hands: why the incrediblediscrepancies?

It took quite a bit of further experimentingand consulting of the Black Powder literatureto arrive at what I now believe to be fairlylogical explanations. I now also realized thatanother issue was at stake - one needed to becareful not to compare apples with pears incomparative burn rate tests.

The first conclusion which I arrived at wasthat completely dried Black Powder (i.e.,moisture free) burns at a marginally slowerrate than slightly moist Black Powder. TheBlack Powder literature seems to bear thisout. This would certainly explain why BlackPowder which had been stored for a fewmonths burnt at a slightly slower rate thanthe same Black Powder just after manufac-

ture. This factor, however, could not ade-

quately explain burn rate discrepancies rang-ing from 70 to 105 cm/second. There had tobe other factors involved.

I cast my mind back over how I had per-formed the tests. One factor stood out veryclearly - ambient temperature. The BlackPowder used for my late afternoon tests wasat a significantly lower temperature to theBlack Powder used in my midday tests. Thiswas because the Black Powder tested at mid-day had just been taken out of the sun and

was actually warm to the touch. Thus theenergy required to ignite this Black Powderwas lower than that needed to ignite BlackPowder which had actually cooled to thesame temperature as its surroundings. Otherfactors also started to emerge during furthertests.

Consistency is the name of the game in prop-erly conducted comparative tests. Where thisis compromised, the test results are alsocompromised. My Black Powder moisturecontents and ambient temperatures had

failed to meet consistency criteria. The fur-ther tests highlighted others.

Black Powder formed into granules burns ata significantly faster rate than the sameBlack Powder as fine powder. The size andshape of these granules play an importantrole in determining the Black Powder's burn-ing characteristics. I found that one reasonfor the slower burn rates I was experiencingwas due to my not properly sifting out all thefine powder. Comparing properly sifted BlackPowder with Black Powder still containing

fine material showed significant differences.

Another factor was the amount of materialused in the tests. When I used a generousamount of Black Powder for a test I got afaster burn rate than when I used signifi-cantly less. It was almost as if I was beingrewarded for my generosity! The light sud-denly dawned on me: the first test I con-ducted when I measured a rate of105cm/second had used a generousamount of Black Powder, the others quite a

bit less. I had actually made a conscious de-

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cision to use less, in order not to waste anyof my batch of valuable fast-burning BlackPowder! But why the differences in results?

I found the answer to this question throughrepeated experiments. Proper testing requiredthat the line of Black Powder being testedcontain enough Black Powder to ensure thatmost of the granules were actually physicallytouching their adjacent granules. This meantthat when each granule ignited it virtuallysimultaneously ignited its adjacent granules.Thinly spread Black Powder however, created

It is possible to make a respectable blackpowder without expensive industrial equip-ment. Any schoolboy with basic laboratorymaterials and a recipe book can whip up abatch of meal powder. Fireworks people havebeen making their own for hundreds of years.

In the beginning stages, a homemade mix-ture may be as good as that of any commer-cial enterprise. It is the subsequent process-

ing which makes the difference betweenpowders manufactured today and the stuffmade by settlers in the early 1800s.

There have been developed several "cottagescale" processes which will yield a functionalblack powder. They all start out the same:weigh the three ingredients and pulverizethem separately. Mix any two together andcombine wet with the third. Then the pyro-technic authorities diverge.

One process works its way around the ne-

cess

Documents

The Best of AFN IV