French polishing is a traditional wood finishing technique commonly used on antique furniture. French polish is not a specific material but rather the effect of applying shellac to a woodworking project that produces a tough surface with a very glossy, mirror-like finish. French polishing dates back as far as the Victorian era but was brushed aside early in the 20th century in favor of less labor-intensive methods of finishing. However, this "lost art" produces a luster that is next to impossible to duplicate with mass-production methods. French polish finishes are also very easy to repair.
Gather the following supplies for a French polish:
- Sandpaper in various grits, including 400- and 1,200-grit
- Tack cloths
- Denatured alcohol
- FFFF-grade pumice inside a salt shaker
- 100 percent extra virgin olive oil or pure mineral oil
- Wool or surgical gauze
- 100 percent cotton fabric (clean, old T-shirts work great)
- Eyedropper bottle
- Squeeze bottles with fine tips
You can use 2-pound pre-mixed shellac, but it's preferable to mix your own, using shellac flakes and denatured alcohol. Mix the shellac to a 2-pound cut, following a shellac mixing chart. Fill a squeeze bottle with the mixed shellac.
Sand the Project
Begin by sanding your project thoroughly, using progressively finer grits of sandpaper and working up to at least a 400-grit. Wipe off all sawdust using a tack cloth. Wipe down the entire project with a cotton cloth slightly dampened with water. This will raise any loose wood fibers, or "hairs" that are on the surface. Allow the project to dry, then sand again with 400-grit sandpaper to knock down the hairs. Wipe the project again with a tack cloth, followed by a cloth slightly dampened with denatured alcohol. The alcohol will remove the last of the sawdust without discoloring the wood.
Make Your Polishing Pad
To apply the shellac you need a pad consisting of a tightly wadded piece of wool or gauze, surrounded by a piece of cotton fabric. To make the pad, make a tight ball of wool or gauze, about the diameter of a quarter. Place this ball in the center of a 6-by-6-inch piece of cotton fabric, and fold the four corners up to meet at the top, forming a teardrop shape.
The idea is that the wool or gauze core of the pad will act as a shellac reservoir. With a moderate amount of shellac stored in the core, pressing the pad onto the wood will leave a thin, even layer of shellac on the surface of the wood.
Shellac is very sticky, sometimes making it difficult to glide the pad across the wood's surface. To combat this problem, you apply a few drops of olive oil or mineral oil onto the outer surface of the pad before each use. If the pad becomes difficult to glide across the surface, add a little bit more oil to the pad. (Because of the way the thin layers of shellac will dry, pure oil will rise to the surface and will not affect the finish. Any impurities that are in the oil may not rise properly, so 100 percent pure, neutral oil is critical.)
Apply a Sealing Coat
To begin applying the French polish finish, apply some 2-pound shellac into the core of the pad, using a squeeze bottle. Tap or press the pad against the back of your hand to spread the shellac evenly throughout the core. The cotton fabric should not be saturated with shellac because you want to apply extremely light, thin layers of shellac to the wood. Less is more in this case.
Next, place a few drops of olive oil onto the pad as a lubricant, using an eyedropper bottle or your finger.
The first coat of shellac will be to seal the wood, so you'll simply wipe the pad (going with the grain) onto the wood. Ideally, avoid starting and stopping at any point on the stock, as this will cause an excessive amount of shellac to be applied at the starting or stopping point. The best method is to use an "airplane" motion: sweep the pad down onto the wood like a plane landing on a runway (going with the grain). When you reach the end of the wood, lift the plane (pad) back off of the runway without stopping. This will help prevent any unsightly blotches or marks.
As you apply this sealing coat, you may find that the cotton cover of your pad is picking up small amounts of sawdust or other fine particles that were left behind. When this occurs, replace the outer cover of your pad with another piece of cotton fabric (and a couple more drops of oil).
After applying a single even base coat of shellac, wait a few minutes and similarly apply a second coat. Repeat once more with a third base coat. Remember to use oil to keep your pad gliding smoothly.
Store your pad in an airtight container and allow the shellac to dry thoroughly.
Fill the Grain With Pumice
Next, use pumice to fill any cracks and smooth the surface as much as possible. With your pad's core nearly depleted of shellac, place a new cover on your pad and add about 10 drops of alcohol to the core. Press the pad onto the back of your hand to even out the liquid, shake some pumice onto the surface of the pad, using a salt shaker. Work small amounts of pumice into the wood with random, circular motions (in small areas at a time). Do not work with the grain, as this will sweep the pumice out of any open pores. Continue until all pores are filled and the sealing coat is extremely smooth.
Apply the French Polish
To apply the French polish, move the original core pad to a new cotton pad cover. Reload the core with shellac, and add a few drops of oil to the cover. Begin applying extremely thin layers of shellac to the piece, working in random, circular motions with firm but even pressure on the wood. This thin layer of shellac will dry very quickly, so you can apply several thin layers in one session. When the pad requires reloading, simply remove the pad and add more shellac to the core.
You may need to make hundreds of passes over the surface of the wood for this first layer of polish. When you're satisfied with the results, take a break and wait a few hours to allow the shellac to dry thoroughly. Be sure to place your pad in an airtight container to save it for the next session.
Once the first layer has dried thoroughly, place a small amount of alcohol into the core of the pad and "spirit" the surface, using the same "airplane" technique you used in applying the sealing coat. This step will remove the oil that has risen to the surface while the shellac was curing. The oil must be removed before applying the next coat.
Repeat the entire polishing and spiriting process six to eight times until you're satisfied with the finish. Examine the surface at all angles under bright light. If any blemishes in the finish need to be addressed, sand them out using 1,200-grit wet/dry sandpaper and a couple of drops of oil. Remove the sawdust with a very light amount of alcohol, and continue polishing and spiriting as necessary to eliminate the blemish and even out the finish.
Add a Glaze, If Desired
At this point, you should have a spectacular, blemish-free, mirror-like finish on your woodworking project. The French polish is completed, and you could merely leave the project as is. However, a final glazing step will add luster.
To add a glaze, make a 1 pound mix of shellac or thin out some of the 2-pound premixed shellac as directed by the manufacturer. Add a small amount of shellac into the pad, along with a couple of drops of oil onto the cover, and apply this mixture using the "airplane" strokes. This thinner layer of shellac will help fill any barely visible blemishes that may remain from the previous step. Be certain to pay special attention to the corners and edges of the project, as they tend to be overlooked. Add as many coats of this final glazing as necessary to reach the finished look that you desire.