Shellac


Shellac is made from a natural resin secreted by the Lac bug, a tiny scale insect that feeds on trees native to India and southeast Asia. The lac resin is processed into flakes which are dissolved in alcohol to make a finish that can be brushed or sprayed. The finish ranges in color from nearly transparent to a natural amber to reddish-brown.  Shellac is one of the oldest and perhaps most underrated of all finishes. It was once considered a premiere finish for fine furniture – and still is in some circles – but has fallen out of favor in modern times with the introduction of synthetic solvent-based finishes such as polyurethane. Compared to these newer finishes, shellac provides limited resistance to water, alcohol, and heat. However, it is ideal when you’re looking for a finish that is fast-drying, light-colored, easy to apply and repair, non-yellowing and non-toxic.

Bleached Shellac

Natural shellac is orange or amber colored and adds a warmth and luster to wood unlike any other finish. It is ideal for dark woods. There is also bleached shellac, often sold as “white” or “clear”. It is typically used for light-colored woods such as maple, birch, holly, or poplar when you want to maintain the natural light color. For a finish with a hint of color, there is also ultrapale and super blonde shellac. Note that all shellac finishes will yellow some over time with exposure to sunlight since shellac contains no natural UV inhibitors.

Pros

  • Quick drying and doesn’t darken with age nearly as much as varnish.
  • Provides an excellent barrier against water vapor exchange and stains.
  • Excellent touch-up material for repairing other finishes.
  • Excels as a sealer and as a barrier coat to contain contaminants such as silicone.
  • Ideal for items that come into contact with food or children’s toys.
  • Very good rubbing properties.

Cons

  • Poor resistance to water, alcohol, heat, and alkali soaps.
  • Not suitable for exterior applications or for heavy-use table tops.
  • Short shelf life when flakes dissolved in alcohol.

Brand Names

 

Bulls Eye Shellac
HOCK Dewaxed Shellac Flakes
LIBERON Shellac Flakes
LIBERON Shellac Sticks
BEHLEN Shellac Flakes
Briwax Shellac Sanding Sealer
SealCoat Dewaxed Shellac Sealer
Application

Shellac can be brushed, padded, or sprayed on. Regardless of method, you must work quickly because the alcohol solvent evaporates rapidly. When brushing or padding, use long strokes in the direction of the grain, all the while maintaining a wet edge. If you miss a spot and the shellac has begun to dry, just leave it until the next coat. Allow each coat to dry about two hours followed by a light sanding with 320 grit self-lubricated sandpaper (optional). Two or three coats will probably suffice although you can apply as many as you wish to achieve the desired effect. Each coat fuses with the one underneath so many imperfections can be remedied in this manner rather than attempting to sand them out.