Wood Finishes

Often, the wood’s color is changed by staining, bleaching, or any of a number of other techniques. Once the wood surface is prepared and stained, the finish is applied. It usually consists of several coats of wax, shellac, drying oil, lacquer, varnish, or paint, and each coat is typically followed by sanding. Finishing of wood requires careful planning to ensure that the finished piece looks attractive, performs well in service and meets safety and environmental requirements. Planning for finishing begins with the design of furniture. Care should be taken to ensure that edges of furniture are rounded so they can be adequately coated and are able to resist wear and cracking. Careful attention should also be given to the design and strength of wooden joints to ensure they do not open-up in service and crack the overlying finish. Care should also be taken to eliminate recesses in furniture, which are difficult to finish with some systems, especially UV-cured finishes

WIt has to be divided in two categories:-

• Colouring Wood
• Basic Wood Finishing Procedure

Colouring Wood :- Wood can be stained to change its colour or left unstained before application of lacquer, or other types of top-coats. Staining should enhance the appearance of wood by reducing colour variation between and within sapwood and heartwood. It also provides a way of giving bland looking woods such as poplar, the appearance of prized furniture woods such as ebony, mahogany or walnut. Wood can be stained using dyes or pigmented finishes. These finishes are available in a wide variety of colours, many of which are not part of the natural colour palette of wood, for example, blues and greens. Pigmented stains tend to highlight the grain (and also sanding scratches), whereas dyes do not have this effect and are more transparent.

Basic wood finishing procedure :-Wood finishing starts with sanding either by hand, typically using a sanding block or power sander, scraping, or planing. Imperfections or nail holes on the surface may be filled using wood putty or pores may be filled using wood filler. Often, the wood’s color is changed by staining, bleaching, or any of a number of other techniques.

• Once the wood surface is prepared and stained, the finish is applied. It usually consists of several coats of wax, shellac, drying oil, lacquer, varnish, or paint, and each coat is typically followed by sanding.
• Finally, the surface may be polished or buffed using steel wool, pumice, rotten stone or other materials, depending on the shine desired. Often, a final coat of wax is applied over the finish to add a degree of protection.
• French polishing is a finishing method of applying many thin coats of shellac using a rubbing pad, yielding a very fine glossy finish.