Varnish

Varnish provides radiant beauty to the wood and can be mixed with glaze to create various textures and patterns. It’s translucent and is mainly used for wood finishing. There are two types of varnishes: Oil varnish and Spirit varnish. The varnish conforming with IS: 347 should be used for finishing and under coat should be of approved brand and manufacturer. Generally ‘Copal’ varnish and superior spray varnish should be used. Airless paint sprayer is a good choice for various coatings spraying, high efficiency, finish surface, good quality.

Surface Preparation for Varnish

• All dust and dirt should be removed from the surface.
• The cracks and holes should be cleaned of dust and be filled with wood putty.
• The surfaces should be finished smooth with the help of carpenter’s plane.
• Previous coats of paint or stain, if any, should be allowed to dry and be rubbed down lightly and washed off.
• For exterior work, a normal dry day should be chosen because exposure to extreme heat, cold or damp atmosphere will spoil the work.
• While applying varnish, care should be taken to avoid forming fume or air bubbles.

 

Application of Varnish

• Two or three coats of clear varnish should be applied for durable finish.
• Next coat should be allowed when previous coat becomes dry.
• The varnish should be applied with full brush and be spread evenly with short light strokes.
• If the work is vertical, the varnish should be crossed and re-crossed and then laid off lightly.
• It should be completed with upward brushing so that varnish could set, flow down and eliminate brush marks.
• If the surface is horizontal, the varnish is worked in every direction with light quick strokes.
• It should be finished in one definite direction so that it could set without showing brush marks.
• The surface should be rubbed down after each coat with fine sand paper except final coat.
• The finished surface should present an even look and fine glossy surface free from stripes, swelling, etc.

Varnishing Old Surfaces

• If old varnished surface is solid, it should be cleaned of grease and dirt with turpentine oil and be rubbed with wet sand paper until the surface is clean and smooth.
• It should be dried and be wiped clean with a soft cloth. If old surface is peeled off and cracked, it will be necessary to remove the entire varnish.

Advantages of Varnish

• Provides radiant beauty to the wood.
• Helps in protecting the wood by binding the surface.
• Helps to prevent hairline cracks and absorb the effects of scratching and external damage.
• Helps in reducing the transfer of moisture between the wood and the surrounding weather.
• Provides softness and lasting flexibility.

Disadvantage of Varnish

Becomes yellowish after a certain time.

Tips are available:

Orifice Size	Fan Width – Inches					Flow Rate		Application	Filter
inch	4” – 6” Fan	6” – 8” Fan	8” – 10” Fan	10” – 12” Fan	12” – 14” Fan	gpm	L/min
0.011”	211	311	411			0.12	0.45	Stain or Lacquer, Varnish	150mesh (red)
0.013”	213	313	413	513	613	0.18	0.68
0.015”	215	315	415	515	615	0.24	0.91	Oil Base Paint	100mesh (yellow)
0.017”	217	317	417	517	617	0.31	1.17	Latex Paint / Acrylic / Enamel	100mesh
0.019”	219	319	419	519	619	0.38	1.44		60mesh (white)
0.021”		321	421	521	621	0.47	1.78
0.023”		323	423	523	623	0.57	2.16	Heavy latex	60mesh (white)
0.025”		325	425	525	625	0.67	2.54
0.027”			427	527	627	0.77	2.91
0.029”			429	529	629	0.90	3.41	Elastomeric / Blockfiller / Primer /	30mesh (green)
0.031”			431	531	631	1.03	3.90
0.033”			433	533	633	1.17	4.43

So from the above sheet, the tip size 0.011 & 0.013″ is recommended for spraying the varnish coat.  we recommend you to use our DP-X6V small airless paint sprayer which has a hoppper attached, and you could pour the varnish into the hopper for spraying it. The hopper would totally save the varanish material without waste.

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