Appearance Protection Durability SafetyEase of

ApplicationReversibility

Rubbing

Qualities

Wax Creates shine Short Term

Needs

frequent

reapplication

Safe when solvents

in paste wax

evaporate

easy, needs

sanding

Can easily be

removed with

solvents

Needs to be

buffed

French

Polish

Some yellow or

orange tint,

depending on

grade used

Fair against

water, good

on solvents

except

alcohol

Durable

Safe when solvent

evaporates, used as

food and pill coating

French polishing

technique difficult to

master.

Completely

reversible using

alcohol

Excellent

lacquerTransparent,

good gloss

Decent

protection

Soft and

somewhat

durable

Uses toxic solvents.

Good protection is

needed, especially if

painted

Requires

equipment.

Completely

irreversible

Excellent soft

finish

varnishTransparent,

good gloss

Excellent

protection

against many

substances

Hard and

durable

Uses toxic solvents,

including toluene.

Breathing protection

is needed

Requires spray

equipment. Used in

professional shops

only

Difficult to

reverse

Excellent hard

finish

Linseed

oil

Yellow warm

glow, pops

grain1, darkens

with age

Very little

Fairly

durable,

depending

on number

of coats

Relatively safe,

metallic driers are

poisonous, rags may

spontaneously

combust

Easy, apply with

rags and wipe off.

Takes relatively

long time to dry

Needs sanding

out as oil is

absorbed

None

Tung oil

Warm glow,

pops grain1,

lighter than

linseed

Water

resistant

Fairly

durable,

depending

on number

of coats

Relatively safe,

metallic driers are

poisonous

Easy, apply with

rags and wipe off.

Faster to dry than

linseed oil

Needs sanding

out as oil is

absorbed

None

Comparison of different wood finishes

OIL FINISHES on wood

Oil finishes are penetrating finishes, protecting the wood from the inside. They are contrasted with film finishes, such as shellac, lacquer, varnish, and water base, which protect the wood by building a film on the surface of the wood.

TYPES OF "OIL FINSHES”

Straight Oil

Oil is a natural substance that is extracted from plants, nuts, fish, and petroleum. Some oils, such as linseed oil and tung oil, cure- they change from a liquid to a solid by absorbing oxygen from the air. Linseed oil absorbs so much oxygen when it cures that its weight increases as much as 12 percent. Oils that cure can be used as finishes. Other oils, such as mineral oil, olive oil, and motor oil, don't absorb oxygen and therefore don't cure. Because they don't solidify, they are ineffective as finishes. Still other oils, such as walnut oil, soybean oil, and safflower oil, are semi-curing: They cure very slowly and never very hard.

Linseed Oil

Linseed oil is extracted from seeds of the flax plant. This oil, in its raw state, is an inefficient finish because it takes many days to cure. So, to make it more effective, metallic driers are added. These driers are usually salts of cobalt, manganese, or zinc. They act as catalysts to speed the curing. With driers added, linseed oil cures in about a day and is called "boiled" linseed oil. All finishes except wax, linseed oil is the least protective. (See "Using Wax as a Finish") It's a soft, thin finish, so it provides no significant barrier against scratching. It's also easily penetrated by water and water vapor

Tung oil is extracted from nuts of the tung tree, which is native to China.Though tung oil is more expensive than linseed oil. Many high-quality varnishes are made with tung oil. Tung oil can be made fairly water-resistant after five or six coats. But it is too soft and thin to resist scratching or water-vapor exchange, and it is difficult to make the finish look nice. The first three or four coats appear flat and splotchy on the wood and feel rough to the touch. Only after five or six coats, sanding between each coat, can you get an even. But the finish is still not as smooth to the touch as linseed oil

the only advantage tung oil has over linseed oil, other than better water resistance after five or six coat.

Film Finish

Film finishes cure hard and can be built up to any thickness you want.

• lacquer

• varnish

• water base

Film finishes protect better than oil finishes because of their thickness on the surface of the wood. The thicker the finish, the better it protects the wood from scratches, water, and water-vapor (humidity)

Lacquer

When lacquer became available in the 1920s, it was widely believed to be the ultimate finish. Lacquer is still the most widely used furniture finish. Lacquer is made by resins and plasticizers

Resin - Nitrocellulose, by treating the cellulose fibers of cotton or wood with nitric and sulphuric acid

The qualities of lacquer

• ease of application with spray equipment

• very quick drying time, which speeds production and all but eliminates dust problems. You can apply three or four coats in a day.

• large variety of thinner/solvent blends, which makes application possible in all types of weather conditions

• ease of repair and removal due to lacquer's evaporative-curing characteristics

• exceptional film clarity, producing the appearance of great depth

• excellent rubbing qualities, due to lacquer's evaporative-curing characteristics

• great versatility for color matching, because there are so many colors available (both pigment and dye), and because you can build the colors very slowly and evenly with a spray gun

• relatively low cost

Limitation of Lacquer

The problem with lacquer is the high percentage of thinner required to put the lacquer into solution. Not only does the lacquer thinner cause air pollution, but it is also highly flammable and bad for your health. it has limited scratch resistance

It shall give silken, smooth finish. The Melamine polish shall have shade and shine, either satin or glossy. It shall be two component polish consisting of a base and hardener. It shall be capable of protecting wood from moisture, heat, cold, scratches, stains, cigarette burns etc. It shall have excellent covering capacity. It shall be applicable to all wooden surface of every shape. It shall be applied using brush or spray gun. It shall require lesser time to dry and there shall be no cracks or pealing off of the polish. There shall not be any undulation on the finished surface nor cracks at joints. It shall have excellent colour, shall be free flowing and shall have good levelling properties. It shall be durable and flexible to absorb cracks. It shall have resistant to scrubs, light rays, heat etc

Application:

Scrapping & cleaning of wooden surfaces & filling the same wherever necessary with putty / primer & applying melamine polish (prior to polishing scrapping shall be done once again to get smooth finished surface) on the outer surfaces of wood.

Varnish

Varnish is made by curing, or semi-curing, oil with a resin. Driers are added to speed the curing. Generally, the oil used linseed oil/ tung oil/ soya oil etc.

Resin(Polyurethane) - resins fossilized from various species of pine trees.

Resistance to heat, wear, solvents, acids, and alkalis.

• Resistance to water and water-vapor exchange:

• Long curing time: Slow oxidation allows you plenty of time to brush varnish without it getting tacky and dragging.

• Difficulty in repairing and stripping.- This is the flip side of good solvent and chemical resistance.

• Difficulty in rubbing to an even sheen: This is the flip side of good scratch resistance.

Oil base enamel paint composition

Petroleum Solvent - 35-42%

Dryers - 0-2%

Resin - 15-25%

Pigment - 30-45%

Regarding application, if using an airless sprayer, thinner is not required, though if brush or roller

is used we recommend 20-25% thinner.