Perfect Coating is very important for wooden furniture manufacturing. Sometimes, Coating on Wood is called Lacquering. Without perfect coating on wood, wooden furniture may not be long lasted. So it is very important. But which is better coating for wood as Coating selection is important! There are a lot of coating methods – Ultra Violet (UV) Coating, Polyurethane (PU) Coating, Polyethylene (PE) Coating, Nitro Cellulose (NC) Coating, Acrylic (AC) Coating, Teak Oil Coating, and Varnishing/Polishing. All these types of coatings are used in wooden furniture manufacturing. In some zones (Malaysia, China, Thailand, Singapore etc) NC is popular but in other zones (Bangladesh, India, Pakistan etc) PU is popular. Among all coatings, UV is the best but its application is costly than others. But I prefer Polyurethane (PU) coating or PU Lacquering. Application process of PU lacquering is easy and little bit environment friendly. In PU Lacquering, specific chemicals are used and they are Filler, PU Sealer, PU Topcoat, Hardener, PU Thinner, Stain etc. Let us see the application process of PU lacquering step by step.
- Filler Application: After accomplishing perfect sanding on wooden furniture with Sand Paper P-120 & P-180 Grit, you may apply Filler as a first coat of PU Lacquer application. It is a primary coating. The main objective of this coating is to fill up the grain of wood. It is applicable for medium pore wood like Teak Champ, Teak, Treated Mango wood etc. It can be used as primary color coating on your wooden furniture also, if you use color fill filler like Filler Walnut, Filler Mahogany, Filler Teak, and Filler Cherry etc. Filler is a mixture of Wood Filler and Slow dry thinner (50:50). Filler can be applied with Brush or wiping with brush. After applying filler on wood/veneer board, remove extra filler from the surface of wood with old cloth or foam. Cure or dry it for about 1-2 hours (depends on environmental temperature). Actually, it is optional for you. If you want, you can skip this process. It is applicable for close pore system. But if you want to get open pore, it is not necessary. But it can give you fantastic wooden texture or finishing after perfect application. Check it in your wooden furniture.
- Sealer Application: After applying filler and curing of filler, you can apply sealer mixture on your wooden furniture or wooden part. You can apply it as your primary coating also. Actually, it is the primary coating in PU Lacquering system and it is mandatory. Without this primary coating you cannot apply next coatings (PU Topcoat). It creates adhesion to the next coatings. Sealer is a mixture of PU Sealer, Hardener and PU Thinner (2:1:1). Perfect ratio is important. You can apply sealer with spray gun and it is better. You can apply sealer with brush but not good. Curing time for sealer application is 1-2 hours (depends on environmental temperature). After curing of sealer, you must sand with 240 Grit Sand Paper to remove powder (Unnecessary). You can apply sealer two-three times to get better finishing. 2nd time or 3rd time application process is similar to this.
- Stain Application: Stain is a transparent color but not solid color. After applying stain on wood, you can get the texture of wood. But if you apply solid color, you can never see texture of wood. Stain Application is optional to you. If you want to get specific color, you need specific colored stain like Stain Walnut, Stain Teak, and Stain Mahogany. Stain may be applied with spray gun or brush. Stain may be applied before or after sealer also.
- Top Coat Application: Top coat application is the final coat of PU Lacquering. It is an important coat and it is mandatory in PU lacquering system. After applying PU Top coat on wooden surface, lacquering is finished and protected from worm & others and resisted by water. Top coat is a mixture of PU Top coat, Hardener & PU Thinner (2: 1:1). PU top coat is applied with spray gun. After applying topcoat, proper curing is important. You cannot touch with hand within 2 hours of topcoat application. You should touch with hand after 8 hours of curing though two hours is OK. 24 hours time is the best curing time. After that, you can pack them (Wooden Furniture) with wrapping materials.
This is the way of PU lacquering. If you follow it you can do it perfectly. There are a numerous lacquer chemical brands in the world. Among them, Inchem Brand, Sayerlac Brand, Baker Brand, Valresa Brand are the good and reliable lacquer chemical brands in the world. You can choose one of them.