Shellac is a liquid that brings out the rich grain in wood. After the alcohol evaporates, a hard shell remains on the wood. Shellacking wood is used to imbue wood with a rich depth often lacking in some wood finishes.
Why Use a Shellac Finish?
- Avoids yellowing or darkening
- Sticks to a wide range of surfaces
- Blocks odors
- Can be mixed from scratch from shellac flakes
- Gives wood a natural look
- Prevents seepage from wood knots or sap
- Accentuates wood's grain
- Deepens the look of finished wood
Before You Begin
Shellac can be purchased in pre-mixed form or it can be mixed from scratch with shellac flakes and denatured alcohol.
Pre-mixed shellac is available in sizes from one pint to five gallons, with one quart being the most common size. Shellac comes clear or pre-tinted in amber. With a shelf life of about three years, pre-mixed shellac is easy to use right out of the can, with no thinning or mixing required.
Most pre-mixed shellac contains three to five percent wax. The wax is a natural byproduct of the lac beetle. Wax can inhibit adhesion.
Pre-mixed shellac is a good choice for small projects of 125 square feet or less since that is the coverage capacity of one quart of shellac.
Shellac can be made by mixing dry shellac flakes with denatured alcohol. Making your own shellac gives you a greater variety of colors, from blonde to dark amber. You're also able to control the thickness of the shellac. Available unwaxed, shellac flakes have an almost unlimited shelf life.
When shellac flakes are added to denatured alcohol, this is referred to as a cut (in a pound-to-gallon ratio). A one-pound cut is a common mixture as it is thin and applies well. For thicker shellac that builds with fewer coats, mix up a two-pound cut.
- One-pound cut: one pound of shellac flakes plus one gallon of denatured alcohol
- Two-pound cut: two pounds of shellac flakes plus one gallon of denatured alcohol
When shellacking wood, work in a ventilated area and use a NIOSH/MSHA-approved air-purifying respirator with an organic vapor cartridge. Protect your hands with nitrile or neoprene gloves. Wear eye protection.
Equipment / Tools
- 1 brush, pad or lint-free cloth
- 1 sandpaper, 80 to 100 grit
- 1 sandpaper, 220 grit
- 1 tack cloth
- 1 glass jar
- 1 kitchen scale (for mixing shellac flakes)
- 1 quart pre-mixed shellac
- 1 gallon denatured alcohol
- 1 pound de-waxed shellac flakes (optional)
Prepare the Surface
Use ammonia and water to wash any surface that is excessively dirty with dust, grease, oil, mildew, or wax. Sand down bare wood with 80- to 100-grit sandpaper.
Prepare the Pre-Mixed Shellac
Let the shellac adjust to the room temperature. Mix the shellac thoroughly with a clean stirring stick. Do not shake. Pre-mixed shellac does not need to be thinned.
Mix the Shellac Flakes (Optional)
If you are mixing up your own shellac from flakes, begin the process a day before you intend to shellac the wood. Add the shellac flakes to the denatured alcohol in a glass jar and stir until the flakes are dissolved.
Shellac the Wood
Apply the shellac to the wood with a brush, pad, or a lint-free cloth. Apply in a thin coat.
Let the Wood Dry
Let the wood dry for at least one hour for re-coating. Ideally, the room should be around 70°F, always remaining between 50ºF and 90ºF. Maintain a humidity level of around 50 percent. Never let the humidity level exceed 85 percent. While the shellac will dry to the touch in about 30 minutes, wait the full hour or more before applying the second coat.
Sand the Shellac
Sand the shellac level and smooth with 220-grit sandpaper. Clean off the shellac dust with a tack cloth.
Apply Multiple Coats
Most furniture requires one or more coats of shellac, interspersed with a light sanding between each coat. For sealing in odors or limiting sap seepage, apply two or more coats of shellac.
Clean the Tools
Clean the brush and other tools in a glass jar with denatured alcohol. Let the tools air-dry.
Is shellac a good wood sealer?
Shellac is a good wood sealer that's relatively safe to use and easy to apply. A shellac finish on wood looks more natural and less plastic than with other sealers like polyurethane.
What are the disadvantages of shellac?
Shellac can develop white rings under cups or mugs. Shellac is water resistant but it is not waterproof.