A furniture finish does two things. It adds color, depth, and sheen to the wood. But more importantly, it protects against stains, abrasions, and resin loss. As wood looses its natural resin, its ability to resist water gain and loss also decreases. If the wood is allowed to expand and contract rapidly as its moisture level varies, the eventual result is cupping, bowing, warping and splitting and glue delamination.
Finishes seem to provide protection in direct proportion to their difficulty to apply. Simple wax finishes, like Briwax, offer the least protection, but, like shoe polish, are simple to apply. Rub on 3 to 4 coats and your done. Reapply every 2 to 3 months. Stain and resin combination finishes like Watco and Minwax offer more protection without a lot more work. Apply 3 to4 even coats. Allow to dry completely between coats. Follow with a clear wax coat. Reapply every 6 months.
Tung oil finishes offer the best compromise between difficulty of application and protective qualities. While not considered a permanent finish, (reapply every 6 to 12 months), its resistance to moisture and stain penetration is better for a longer time than either wax or stain/resin finishes. Application is easy but time consuming. First, stain or dye the piece to be finished. Allow 24 hours to dry. Brush on a 50/50 mix of boiled linseed oil and mineral spirits. This will give you a faster finish build. When dry, 6 to 10 coats of tung oil with a foam brush. Wet sand or steel wool (#0000) to remove dust after every 3rd coat. Polish out or Wol-Wax the final coat.
This brings us to the finish of choice for professional refinishers and fine furniture manufacturers - lacquer. More difficult to apply properly, it offers a far longer life expectancy and more resistance to abrasion, chemicals, and moisture penetration than the other finishes we have considered, while still allowing the wood to breath and climatize properly.
Lacquer finishes are applied in two stages - the sealer coats and the top coats. These may be applied by hand, but more often are sprayed on. Stain, dye or glaze the wood to the desired color and allow to dry 24 hours. Apply the first coat of sealer. Like every coat of sealer, this should go on every square inch of the piece, inside and out. This will keep the moisture transfer rate slow and even on both sides of the wood. If the wood is very grainy, but you desire a smooth flat finish, a pastewood filler is applied at this point. The filler can be dyed to accent the grain.
Using Mineral spirits to control its consistency, rub in across the grain. Allow the dry slightly and wipe the surface clean with burlap or a cotton cloth. After 24 hours, apply another heavy coat of sealer, allow to dry, and sand with 220 -240 grit paper. Be careful not to go through the finish. Repeat as needed. The objective here is to fill the grain, but not build the surface coat any thicker than 1 mil, which is one strong coat of finish. Next we apply the top coats.
Apply the first coat, allow to dry, and wet sand with 400 grit paper. At this point the piece may be shaded if need be. The final top coat is then applied, and, when dry, wet sanded with 600 grit paper. This will eliminate dust and orange peel. A light rubbing compound will get rid of sanding scratches. If a high gloss look is desired, follow with a glazing compound. If a lower sheen is wanted, use a light application of Wol-Wax or rottenstone. The finish will cure for 30 days. During this time don't apply any wax, which would prevent the finish from breathing and curing properly.
We recommend that your use a polish, like Guardsman Furniture Polish, no more often than once a month. For every day dusting, simply use a damp rag. Never use anything containing silicones.
Good luck with your project!