When you get ready to apply the shellac, blend it with denatured alcohol to get the desired cut. Never shake the can to mix it, as this creates air bubbles. When applying, brush with long, even strokes. Short strokes leave too many brush marks. Allow the shellac to dry for two hours between coats. Once you've built up a deep finish, allow it to dry for a day, then rub the surface smooth with 00# steel wool. If you want a high gloss, follow-up with progressively finer grades of steel wool. Polish with a good, high quality paste wax.
Shellac can also be applied without a brush, using a technique called French Polishing that will produce a mirror-like finish that's beyond description. To do this, wrap a piece of fine linen around a large ball of cotton. Moisten the pad with 5-pound cut shellac, then sprinkle with linseed oil. Rub the surface of the wood is a circular or figure-8 motion. When the pad begins to stick, moisten it again with more shellac and linseed oil. The body of the finish will start to build up as you rub. When you've attained the desired lustre, sprinkle the pad with alcohol and rub the surface with the grain of the wood to remove any circular marks.
Lacquer has as its base, cellulose, a chemical made from cotton. Lacquer is extremely fast-drying and is suitable for both wood and metal finishing.
Until recently, lacquers had to be sprayed onto a project. They were so quick-drying that they dried right on a brush. However, today, slower drying, brushing lacquers are relatively easy to find. These finishes are especially suitable for smaller projects -- picture frames, carvings, pens/pencils, small shelves, any project where you can cover the entire project surface with a single brush-full of lacquer.
If you've stained he wood, first seal it with a lacquer sealer to keep the stain from bleeding into the lacquer top coat. Sand the sealer lightly with 5/0 garnet sandpaper and wipe with a tack cloth to remove all dust. Brush the lacquer on in long, even strokes with the grain, as with shellac. Allow to dry for two hours between coats. If necessary, you can sand down the high spots where the brush strokes overlapped with 6/0 garnet sandpaper.
After the final coat, let dry for a day. Rub down the finish with a felt pad and rubbing compound made especially for use with lacquers. When the surface is smooth, wipe off the grime and apply a good wax.
For years, varnish has been the mainstay of wood finishers and refinishers. It's made from a variety of tree resins, blended with drying oils. The resulting finish is harder than shellac, less finicky than lacquer and can be used on a variety of applications.
When using varnishes, it's important that you take great care in preparing the surface prior to application. Wash the project down with benzene to remove all traces of grease and dirt. If you've stained the wood, apply a wash coat of shellac and alcohol and sand lightly with 5/0 garnet sandpaper. Wipe thoroughly with a tack cloth.
Brush the varnish on across the grain in long strokes. Wipe the excess varnish out of the brush and go over the surface again with the grain. Wipe the brush again and go over the surface once again with the grain, this time, using the tip of the brush to smooth the varnish. Allow to dry for six hours, then sand lightly with 6/0 or 7/0 garnet sandpaper soaked in benzene. Wipe down thoroughly with a tack cloth. Apply successive coats in the same manner as he first.
After the final coat, allow to dry for one to two days. The varnish may look awful, showing marks and dimples, but don't worry, as these can all be rubbed out. Saturate a piece of felt with linseed oil, sprinkle with pumice stone and rub with the grain in long strokes. Wipe and buff with a soft rag.
Caring For A Natural Finish
Periodically, a natural finish will need cleaning and polishing. Lemon oil makes a good cleaner and won't build-up. A carnauba paste wax will replenish the finish, keep it from turning brittle and fill any tiny scratches. Don't use commercial furniture polishes; these could react with natural finishes and ruin them.