Myths about Aluminium Brazing with Non-Corrosive Fluxes

NOCOLOK® Flux Brazing Technology

Myths about Aluminium Brazing with Non-Corrosive Fluxes

NOCOLOK® Flux Brazing Technology

Daniel C. Lauzon Hans-Walter SwiderskySolvay Fluorides, Inc., St. Louis, MO, USA Solvay Fluor und Derivate GmbH, Hanover, Germany

Table of Contents

4

Introduction 5

Myth No. 1: A Flux with Smaller Particle Size is More “ACTIVE” and Leaves Less Flux Residue 6

Myth No. 2: Fluxes With a Lower Melting Range are Superior 9

Myth No. 3: Some Fluxes Produce Less Hydrogen Fluoride (HF) than Others 10

Myth No. 4: “Pure” Flux Compounds (i.e. “Pure” Fluxes) are Better for Brazing 13

Myth No. 5: Non-Corrosive Fluxes Absorb Moisture (i.e. NOCOLOK® Flux is Hygroscopic) 15

Myth No. 6: More Flux is better 16

Myth No. 7: Flux Slurry Concentration is the Only Factor to Control Flux Load 17

References 18

More Information 19

Introduction

5

where decisions are made basedon circulated fiction rather thanactual facts.

The intention of this publicationis thus to address the mostpopular myths and comment ontheir technical merits based onpublished literature, fundamentalchemistry and Solvay’s ownresearch work. We hope to en-courage the reader to deal onlywith the facts about NOCOLOK®Flux brazing, to promote a betterunderstanding of non-corrosiveflux properties and use.

application, flux performance, andprocess optimisation. In fact, thesophistication of today’s CABbrazing furnaces, combined withyears of process improvements,has reduced typical flux loads byalmost 50 %.

Despite the fact that CAB brazingis a mature technology, over theyears many misconceptions aboutcertain flux properties have beenspread and falsely accepted. Inmany cases these misconceptionshave caused confusion with theheat exchanger manufacturers

or nearly 20 years,NOCOLOK® Fluxbrazing – or Con-trolled Atmos-phere Brazing(CAB) with non-corrosive fluxes –has been the pre-ferred process forproducing alu-minium automo-

tive heat exchangers. In the twodecades since the process was firstintroduced to the automotiveworld, a great deal has beenlearned about flux handling, flux

Myth No. 3

12

Figure 5: Typical X-Ray Diffraction (XRD) Diagram of NOCOLOK® Flux

*2Theta

counts

10,000

8,000

6,000

4,000

2,000

010 20 30 40 50 60

ph-594 K2AlF5 · H2O 94_1441 K2AlF5 · H2O

ph-463 K2AlF5 Phase 1 K2AlF5

ph-388 Potassium Aluminium Fluoride KAlF4

Based on the above information,the authors strongly believe thatthe amount of hydrogen fluoridegenerated is not flux-specific, butdepends on several factors such as:

There is no evidence to suggestthat some fluxes produce less HFthan others.

� Flux load (i.e. quantity) goingthrough the furnace – fluxloading and componentthroughput

� Temperature profile – heatingrate and time at temperature

� Furnace atmosphere conditionssuch as nitrogen flow anddew point

Myth No. 1

6

Figure 1: DSC Scans for Granulated NOCOLOK® Flux Samples

20mW

0 5 10 15 20 25 30 35 40 min

80 100 200 300 400 500 520 540 560 580 °C

ome rumours havebeen spread that aflux with a smallerparticle size leadsto better brazingand results in amore pleasingpost-braze ap-pearance. But thefacts are verydifferent.

It is true that a flux with a smallerparticle size covers the surfaces ofthe work-piece more completely

smaller particle size. The net resultis that this would affect thekinetics of melting – how quicklythe flux melts – but it does notaffect the melting temperaturerange. This is analogous tocrushed ice melting quicker than ablock of ice, but both melt at thesame temperature. Figure 1 showsthe melting action of various par-ticle size fluxes using DifferentialScanning Calorimetry or DSC. Asexpected, all particle sizes melt atprecisely the same temperature.

A Flux with Smaller Particle Size is More “ACTIVE” and Leaves Less Flux Residue

than the same quantity of fluxwith a larger particle size. Smallerflux grains will also adhere betterto those surfaces, assuming thatthe two fluxes to be comparedindeed show a difference inparticle distribution.

As particle size decreases, the totalsurface area of the flux increases.This allows a higher surface areaof flux to be in contact with thework-piece. During heat up, theremay be more efficient energytransfer to the flux with the

Myth No. 1

7

It is true that particle size dis-tribution of a flux affects slurrycharacteristics. A finer powder willstay longer suspended (i. e. itsettles slower) than a coarser prod-uct. Material with larger grainsseems to build-up more rapidlyon inside surfaces of slurry tanksand spraying equipment. Re-gardless of the specific particledistribution of a flux, continuousagitation is necessary to preventsettling and build-up. Regularmaintenance is the only way toavoid the formation of solidifiedmaterial residues.

Finally, the appearance of thepost-braze surface is only relatedto the initial flux loading, notparticle size. Once the flux melts,it is completely liquid. In itsmolten state, the flux has noparticles – neither large nor fine.Once the flux is liquid, itimmediately spreads out and wetsthe surfaces. Upon cooling andsolidification, the amount of fluxresidue and its distribution on thesurface of the work-piece is relatedentirely to the initial flux loading,and not particle size.

It is also speculated that the abilityof the flux to melt and spread(activity) increases as particle sizedecreases. In fact, the activity ofthe flux is related to chemistry andphase composition, not particlesize(1). Spreading is simply a liquidphase reaction unrelated to theparticle size distribution of thesolid phase.

A practical example showing howflux particle size is unrelated tobrazing results is comparingNOCOLOK® Flux (average par-ticle size 2 – 6 µm, see Figure 2)used for wet fluxing withNOCOLOK® Flux Drystatic (av-erage 3.5 – 25 µm, see Figure 3)used for electrostatic fluxing. Heatexchangers brazed by wet fluxingcan be brazed with the sameresults using dry fluxing, and theonly difference is the particle sizeof the flux. The success simplydepends on applying the fluxuniformly.

Myth No. 1

8

100 %

50 %

0.1 1 10 100

100 %

50 %

0.1 1 10 100

Figure 2:

Typical Particle Size Distributionfor NOCOLOK® Flux

Used For Wet Application

Figure 3:

Typical Particle Size Distributionfor NOCOLOK® Flux Drystatic

Used For Dry(Electrostatic) Application

Myth No. 2

9

Table 1: What Takes Place During Brazing?

Surface Temperature of Temp. Duration with a Duration with aAluminium Components Range Action Heating-Ramp of Heating-Ramp of

∆ 25°C/min 15°C/minBelow 560°C Uniform heat-up Depends on brazing cycleBetween 560 and 575°C 15°C Flux melting 0.6 min = 36 sec 1 min = 60 sec

Between 575 and 585°C 10°C Flux spreading and 0.4 min = 24 sec 0.66 min = 40 secsurface wetting

Approximately 585–605°C 20°C Brazing range of 0.8 min = 48 sec 1.33 min = 80 secAA 4045 filler alloy

Approximately 590–610°C 20°C Brazing range of 0.8 min = 48 sec 1.33 min = 80 secAA 4343 filler alloy

Fluxes With a Lower Melting Range are Superior

composition, and it begins to dryout. Given enough time, it ispossible for the flux melt to com-pletely dry out before reaching themaximum peak brazing tem-perature.

A good brazing flux only needs tobe available just before filler metalmelting. Table 1 describes whathappens at brazing temperature:

the merits of “early” flux melting,and thus “prolonged” flux action.However, the facts are verydifferent.

As soon as the flux begins to melt,one of the components of the flux– KAlF4 – begins progressivelyevaporating, with a vapour pres-sure determined to be 0.08 mbarat 600°C(2). Evaporation of KAlF4

causes the flux melt to change

here are claimsthat a lower melt-ing point flux isbetter for brazing(i. e. melting be-tween 550 and560°C – approxi-mately 10 –15°Cbelow conven-tional fluxes). Theidea here is to try

to fool the engineer by illustrating

As soon as the flux melts, it beginsto dissolve the oxide layer, and thissolvating process continues untilthe oxide is removed, even if thefiller alloy has melted. The abovetable shows that even if the periodof flux activity would be limitedonly to the time between completeflux melting and the lower brazingrange of AA 4045, it is still ade-quate. The authors thus consider aflux melting range between 560and 575°C as the most suitable for

aluminium brazing with Al-Sifiller alloys.

One should not completely dis-miss the point made about “pro-longed” fluxing action with lowermelting point fluxes. However,once again, all the informationmust be examined. Yamaguchi etal. have shown that with anincrease in the K2AlF5 content, theflux will start to melt at a lowertemperature so that the flux will

work at a lower temperature.However, even if KAlF4 evapo-ration is ignored, the same studyconcluded that increasing theK2AlF5 content eventually preventsthe flux from spreading smoothly,and therefore affects the efficiencyof the flux(1).

The evidence presented here issufficient to demonstrate thatmerely lowering the melting pointdoes not in itself create a betterbrazing flux.

Myth No. 3

0-10-20-30-40-50-60-70-80-90

-100-110-120-130-140-150-160-170-180-190

50 100 150 200 250 300 350 400 450 500 550 600 650 700

Date/TimeOperator:Lab: SBS–S–TCAComment: Pt, 20°/min

Specimen: Nocolok Batch 4090 49.00 mg

Atmosphere: Air 0.00 l/minReference File: 01PT0200

DTA signal (smoothed) [00_0259D]

dM-rel [00_0259D]

Temperature (smoothed) [°C]

DTA

sig

nal (

smoo

thed

) [µV

]

dM-r

el [%

]

Loss-On-Heating (LOH)related to dehydration

of K2AlF5 · H2O Volatile compoundsbetween 250 and 550°Capproximately 0.2–0.5 %

Flux melting range560–575°C

Rapid flux evaporationabove melting temperature

1.0

0.5

0.0

-0.5

-1.0

-1.5

-2.0

-2.5

-3.0

-3.5

-4.0

-4.5

-5.0

-5.5

-6.0

10

Figure 4: Differential Thermal Analysis (DTA) Diagram for NOCOLOK® Flux(Batch 4090) – Heating Rate 20°C/Min

long with mostother aluminiumbrazing fluxes ont h e m a r ke t ,NOCOLOK® Fluxis an inorganicfluoride salt con-sisting of potas-sium fluoroalu-minates of the ge-neral formula

K1-3AlF4-6. Fluxes of this type areconsidered intrinsically non-corrosive in that they are non-hygroscopic, they do not react withaluminium whether solid or mol-ten, and can remain on the surfacesof brazed components as a thin,tightly adherent and inert residue.

Goad have measured the vapourpressure of KAlF4 over the fluxmelt to be 0.08 mbar at 600 °C(2).Takemoto et al. revealed in theirexperiments that the mass of aKAlF4 – K2AlF5 · H2O type fluxdecreased during brazing becauseof evaporation. At 600°C, theydetermined that the rate of fluxloss was 0.02 µg/sec (3). Solvay’sown TGA analysis (with a heatingrate of 20 °C/min, see Figure 4),showed that the quantity ofvolat i le compounds inNOCOLOK® Flux between 250°Cand 550°C is approximately 0.2 to0.5 wt %.

Some Fluxes Produce Less Hydrogen Fluoride (HF) than Others

Although there are several brandsof non-corrosive aluminiumbrazing fluxes, at brazing tem-perature, they are all understoodto be a mixture of KAlF4 andK3AlF6. When heated up to bra-zing temperature, one of the fluxcomponents (KAlF4) starts toevaporate in small quantities. Thefumes produced by evaporatingflux contain fluoride, and canpotentially react with moisturetraces present in the gas phase(from surrounding atmosphere)to form hydrogen fluoride (HF).

This is conclusive for severalreasons. The flux has a measurablevapour pressure. Thompson and

Myth No. 3

11

Diagram 1: HF Generated as Function of Moisture Content(5)

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

HF

Co

nce

ntr

atio

n in

mg

/g o

f Fl

ux

Moisture Content in Nitrogene in mol%0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

–43°C

–9°C

–2°C

–1°C

0°C

Approximate Dewpoint

the generation of HF, Thompsonand Goad(2) also proposed thatAlF3 dissolved in the flux melt issubject to hydrolysis according to:

2 AlF3 + 3 H2O Y Al2O3 + 6 HF

What is clear is that in all cases,HF is shown as a reaction product.As for the quantity, Field andSteward have indicated that theamount of HF formed is typically20 ppm in the exhaust of acontinuous tunnel furnace (4).Solvay’s research work confirmedthat even when flux on aluminiumis heated in a bone-dry nitrogenatmosphere, a small quantity ofHF is still generated(5). A source ofhydrogen must be made availablefor HF to be formed even underbone-dry conditions, and thismight include reduction ofaluminium hydroxide, degassingof furnace walls, leakage or otherless obvious sources. The workproved that even under idealconditions, it is virtually im-possible to avoid some trace HFformation.

and will not exist, and in whattemperature or humidity regimes.This is why more than onemechanism has been proposed forthe generation of HF, but nounique reaction mechanism hasbeen identified:

3 KAlF4 + 3 H2O YK3AlF6 + Al2O3 + 6 HF

2 KAlF4 + 3 H2O Y2 KF + Al2O3 + 6 HF

While the evidence above pointsto gas phase reactions betweenflux fumes and water vapour for

It is clear that all fluxes will createflux fumes, with strong evidencesuggesting that the vapourprimarily contains KAlF4. Withregard to CAB brazing (furnacebrazing) where traces of moistureare always present even at – 40 °Cdew point (which corresponds to106 ppm H2O at atmospherepressure), a number of com-pounds can be formed in thesystem K – Al – F – H – O. To ourknowledge there has been noacademic effort to create athermodynamic model of thissystem. Thus, it is impossible topredict which compounds will

Myth No. 4

13

Flux Components – Phase Transformation During Brazing

Major Minor

As Manufactured KAlF4 and K2AlF5 · H2O and/or K2AlF5

(I) + (II)

K2AlF5 (I)

K2AlF5 (II)

At BrazingTemperature KAlF4 + K3AlF6

Melt

90°C–150°C

290°C–330°C

490°C–495°Cand

500°C–520°C

ome believe thatpure flux phasessuch as pure KAlF4

or K2AlF5 are bet-ter for brazingthan mixtures ofphases. Some haveeven referred tothe presence ofK2AlF5 as an “im-purity”. This couldnot be further fromthe truth.

K2AlF5 is necessary to achieve theproper ratio of KAlF4 and K3AlF6

at brazing temperature, thenecessary condition to form theeutectic. This can be explainedmore thoroughly by examiningthe following schematic:

“Pure” Flux Compounds (i.e. “Pure” Fluxes) are Better for Brazing

The efficiency of a flux is char-acterised by a combination of fac-tors such as melting and spread-ing, fillet formation and clearancefilling. Yamaguchi et al. showedthat the pure flux phases, namelyKAlF4 and K2AlF5 are not the mostefficient in optimising these fluxcharacteristics (1). In fact, theyshowed the flux to be highlyeffective when a combination ofKAlF4 and K2AlF5 was used.Furthermore, the presence of

Myth No. 4

14

Figure 6: Melting Phase Diagram for the Potassium Fluoride (KF) –Aluminium Fluoride (AlF3) System

1200

1000

800

600

400

200

20 40 60

Tem

per

atu

re °

C

KF mole % AIF3

α-K3AIF6+KAIF4KF+α-K3AIF6

KAIF4+α -AIF3

β-K3AIF6+KAIF4KF+β-K3AIF6

KF+τ-K3AIF6

τ-K3AIF6+KAIF4

KAIF4+β -AIF3

KF+meltKAIF4+melt

τ-K3AIF6+melt

β -AIF3+melt

PAIF3 = l atm.

crystal water from 90°C on. Whenthe temperature is further in-creased within the ranges of90°–150°C, and 290°C–330°C, twodifferent crystallographic modi-fications of K2AlF5 are formed(6).When the furnace temperature israised above 490°C, K2AlF5 beginsto dissociate:

2 K2AlF5 Y KAlF4 + K3AlF6

The exact amount of K3AlF6 nec-essary for a eutectic flux com-position is obtained from theoriginal K2AlF5 content. It is theratio between the total amount ofKAlF4 (as manufactured and dis-sociation of K2AlF5) and K3AlF6

that forms the basis for fluxmelting.

In fact, the flux manufacturerchooses the ratio of KAlF4 andK3AlF6 based on the eutecticAlF3-KF phase diagram (see left),which was first constructed in1932(7) and further researched andrefined in 1966(8).

There can be no doubt that a fluxmust contain more than just thepure phases – and it must containthese phases in an extremelyprecise ratio – in order to workeffectively and to meet theconditions for eutectic formationwhich controls the melting point.

brazing process, the materialundergoes essential physico-chemical transformations. Whilethe chief component, KAlF4, issimply heated up, the compoundK2AlF5 · H2O begins to lose its

As manufactured, a flux typicallycontains a mixture of KAlF4 andK2AlF5, where the K2AlF5 may ormay not be hydrated (see Figure5:“Typical XRD Diagram ofNOCOLOK® Flux”). During the

Myth No. 5

15

hemicals (solid orliquid, inorganicand organic sub-stances) are hygro-scopic when theyattract moisturewhile stored in –or exposed to – airwhere traces of hu-midity are alwayspresent. Conse-

quently, hygroscopic liquidchemicals (e.g., sulphuric acid,glycerine, alcohol, etc.) becomediluted, while hygroscopic solidmaterials begin agglomeration andbecome liquified. Hygroscopicsolids are mainly salts that arehighly soluble in water (e.g.MgCl2, CaCl2, P4O10, etc.). Theirsaturated solutions have a lowwater vapour pressure because ofthe high salt concentration. Watervapour from surrounding aircondenses on the salt, resulting in asaturated solution. The salt startsto liquefy, i.e. it is hygroscopic.

Hygroscopicity should not bemistaken for the simple physicaladsorption of humidity on apowder surface. Moisture gen-erally adheres to all surfaces de-pending on the humidity level ofthe surrounding atmosphere, thesurface structure and surface area,as well as temperature andpressure conditions. Physical ad-

The only interaction ofNOCOLOK® Flux with moistureis the re-hydration of phase IK2AlF5 to K2AlF5 · H2O. In thedrying step of the NOCOLOK®Flux production, most of theK2AlF5 · H2O is converted intoK2AlF5 phase II. K2AlF5 phase IIdoes not pick up water moleculesfrom air, and under theseconditions will not transform toK2AlF5. Traces of phase I K2AlF5

present in the flux will most likelyre-hydrate within six months afterproduction. The total difference ofloss-on-heating analysis related tothe re-hydration of phase I K2AlF5

after this period is on average0.5 %, without affecting the visiblematerial appearance. As far as weknow, there is no change in anychemical or physical flux charac-teristic related to this effect.

Adsorption of moisture underhumid conditions is an absolutelynormal physical effect for apowder with large surface area.The flux has a very low watersolubility and it will not liquefy inair by attracting humidity.NOCOLOK® Flux does notchemically react with moisture,and thus is not hygroscopic!

Non-Corrosive Fluxes Absorb Moisture (i.e. NOCOLOK® Flux is Hygroscopic)

sorption involves neither a chemi-cal reaction nor any dilution orliquefying. Adsorption on powdersurfaces may result in agglom-erations or clumping; however,these effects are reversible. Whenthe humidity level of the sur-rounding air decreases or thepowder surface temperatureincreases, the adsorbed water mol-ecules are released (de-sorption)until a balance of the system isagain reached.

On a more practical note, theauthors have tried to analyse thedifference in moisture content ofsome powder samples used inelectrostatic fluxing. One samplewas taken from a fluxing booth towhich moist air had access. Poorfluidisation of the flux powder wasobserved, resulting in ag-glomerates. The other sample wasfrom a fluxing booth in whichdried air was used and noperformance problems were re-ported. Both samples were ship-ped to our lab for analysis. Theresults demonstrated only theloss-on-heating (LOH) relatedfigures (see next paragraph), andno difference was found betweenthe two samples. What happenedwas simply that the material,which had adsorbed somehumidity in the fluxing booth, hadlost all of this adsorbed moisturebefore it could be analysed.

Myth No. 6

16

An initial flux load that is too highwill result in excess post-braze fluxresidue. Flux drips (i. e. visiblecrystalline residue) can form onthe product and downgradeappearance. In some cases, excessflux residue can cause problemswith gaskets and seals, as well aswith surface treatments afterbrazing (e.g. painting).

Over-fluxing can lead to morerapid flux build-up on the fixturesand increase the maintenanceintervals.

Over-fluxing is a waste of flux,which will inevitably increaseprocess costs.

While “more flux is better” is truein some circumstances, there is anoverwhelmingly negative impactfrom increasing the flux load tocompensate for some processdeficiencies.

atmosphere contaminants. Whenhigher Mg-containing alloys areused, higher flux loads cancompensate for faster re-oxidationrates, and for the chemicalinteraction between magnesiumand fluoride.

In most cases, though, more flux isused to mask furnace atmosphereor heat exchanger design defi-ciencies such as poor componentfit-up. Flux is frequently seen as acure-all bandage. While this isoften the case, it should only beused in this fashion temporarily,until the real issues are resolved.

Over-fluxing leads to the gen-eration of more effluent wherecondensed KAlF4 vapours willload up the dry scrubber morequickly. Continuous drips on thefurnace floor caused by over-fluxing can lead to an accu-mulation of flux, which caneventually deflect the mesh belt orprematurely corrode the muffle.

his is anothermyth – althoughthere can be sometruth to it. But allthe specifics mustbe considered be-fore accepting thesimple statementthat more flux isbetter.

In heat exchanger problem areassuch as in tube-to-header joints orwhere Mg-containing alloys areused, it is common practice toincrease the flux loading. Dualconcentration fluxing stations(where one concentration of fluxslurry is used for the fin pack anda higher concentration for thetube-to-header joints) are stillcommon. Manual flux applicationwhere 6XXX series alloys are usedfor fittings is also commonpractice. In these cases, more fluxis better because it promotesmaximum filler metal flow tocritical joint areas while mini-mising exposure to furnace

More Flux is Better

Myth No. 7

17

Diagram 2: NOCOLOK® Flux Slurry – Relationship between Slurry Density and Concentration

1.0000

1.0500

1.1000

1.1500

1.2000

1.2500

0 5 10 15 20 25 30

Concentration [%wt]

Den

sity

[g

/ml]

Density = 0.008*Concentration + 0.9893R2 = 0.9971

s a flux producerand supplier,Solvay has receivedmany enquiriesover the years as-king what slurryc o n c e n t r a t i o nshould be used toachieve the opti-mum flux load ona part to be brazed.

This specific request is related tothe belief that flux slurryconcentration is the only factorcontrolling flux loading.

There are in fact many otherfactors affecting flux loading and

While the flux slurry concen-tration is important, all theseother factors also contribute tocontrol the flux loading. If any onefactor is changed, the flux load willchange. The goal is to balance allfactors to achieve the desired fluxquantity on the surfaces.

Flux Slurry Concentration is the Only Factor to Control Flux Load

they must all be taken intoconsideration when targeting acertain level. First is the appli-cation method whether it bedipping, spraying or flooding.Even the type of spray will depositmore or less flux on thecomponent surfaces, depending onnozzle configuration (atomisingspray vs. shower effect). Thecomponent surface wettability (i.e.the ability of the aluminiumsurface to be uniformly coatedwith a water-based flux slurry),conveyor belt speed, and thestrength and volume of the airblow-off all play a role incontrolling flux loading.

References

18

(1) Yamaguchi M., Kawase H., Koyama H. Furukawa, Review No. 12, 1993, p145–149

(2) Thomson W. T., Goad D. W. G., Can. J. Chem., 1976, Vol. 54, p3342–3349

(3) Takemoto T., Matsunawa A., Kitaawa A., Journal of Materials Science Letters, 1996, Vol. 15, p301–303

(4) Steward N. I., Field D. J., SAE 870186, 1987

(5) Lauzon D. C., Belt H. J., Bentrup U., Therm Alliance International Invitational Brazing Seminar, Detroit, 1998

(6) Wallis B., Bentrup U., Z. anorg. allg. Chem. 589, 1990, p221–227

(7) Fedotiev P., Timofeff K., Z. anorg. allg. Chem. 206, 1932, p263–266

(8) Phillips B., Warshaw C. M., Mockrin I., Journal of the American Ceramic Society, 1966, V. 49 No. 12, p631–634

More Information

19

You Want More Information. You’re Welcome:

“The NOCOLOK® Flux Brazing Process”the complete detailed technical brochure.Available in several languages.

“The Technical Brazing Centre” –NOCOLOK® Flux Brazing Services.Available in several languages.

The brochure “TheNOCOLOK® Flux ProductStewardship Concept”.

“Flame Brazing with NOCOLOK® Flux” –the complete detailed technical brochure.Available in several languages.

The compendium on CD-ROM:With the NOCOLOK‚ Flux Dictionary,all print publications and theNOCOLOK® Flux Multimedia Show.

The video “NOCOLOK® Flux –The Brazing Story”. Interestingand informative.

The video “Live on stage –The Solvay Brazing Seminar”.

The video “Flame Brazing”.

All statements, information, and data given herein are believed to be accurate and reliable but are presented without guarantee, warranty or responsibility of any kind, expressed or implied. Statements or suggestions concerningpossible use of our products are made without representation or warranty that any such use is free of patent infringement, and are not recommendations to infringe any patent. The user should not assume that all safety meas-ures are indicated, or that other measures may not be required.

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31/3

90/0

4.02

/007

/3.0

00