Wood finishes come in two primary types, surface finishes and penetrating finishes. Surface finishes, such as varnish, shellac and polyurethane, coat the surface of the wood with a hard, shiny and protective layer. Penetrating finishes, such as natural oils and pigmented penetrating stains, soak into the wood and become part of its surface. Although shellac can be an acceptable finish for certain mahogany pieces, many people choose a penetrating finish to allow beautiful mahogany wood to appear more natural.
Benefits of Penetrating Finishes
Penetrating finishes soak into the surface of the wood, leaving the natural wood grain visible. Mahogany is popular partially for its attractive straight wood grain, and penetrating finishes allow this quality to show through. Mahogany's open-pore structure also helps it soak up penetrating finishes easily. Penetrating finishes of all types slightly darken the wood, enhancing its natural color. Some penetrating finishes contain pigments designed to stain the wood a different color, which allow users to make mahogany darker or more reddish if desired. Penetrating finishes also make it easier to repair scratches and dents than surface finishes do.
Shellac and Surface Finishes
The best type of finish depends on the desired look as well as the use of the mahogany. Utah State University recommends shellac as a surface finish option for mahogany, but it also notes that shellac easily sustains scratches, chips, moisture damage and alcohol damage. Therefore, shellac is only a good finish for mahogany that undergoes little wear and tear, such as decorative carvings or wooden furniture frames. If you want a decorative piece of mahogany to have surface finish, shellac is a good option. For flooring, doors and other more heavily used wood furnishings, a penetrating finish will show less wear than a surface finish.
As their name suggests, fillers fill in open pores on the surface of open-grain woods, such as mahogany. They give the wood a smoother surface. Many people like the open-grain texture of mahogany, but some prefer the smoother look of mahogany with a filler. Filler goes on before stain and finish.