A Comprehensive Guide to French Polish
In woodworking, building anything made out of wood is only a part of the job. After making something out of wood, we need to apply a finish to its surface. It is not enough to only smoothen the surface by using a planer, file, or sandpaper. We usually apply what we call a “finish.”
By applying a finish, we protect the wood’s surface from water and scratches and abrasions. In addition to the protection, it also enhances the appearance of the wood. We get different types of finish, and one of the most popular ones is French polish. If you notice an exceptionally polished piece of wood on furniture or a musical instrument, it could be French polished wood that you are looking at. Not only does wood that is finished with French polish look good, but much hard work goes into achieving the desired results.
What is French Polish?
French polishing is not a substance but a process. It refers to the usage of shellac dissolved in alcohol and applied to the surface of wood. We usually use French polish with the help of a “rubber.” The rubber in French polishing is not made of rubber but is a combination of a rag and cotton waste.
On applying French polish to the wood’s surface, the alcohol evaporates, leaving a film of shellac. Once the shellac dries, it creates a refined, polished look that gives the wood a classy look.
Origin of French Polish
Shellac first appeared in the 16th century in Europe. But French polishing technique only emerged a couple of hundred years later, during the 19th century. A French cabinet maker began using shellac in a particular way, and his technique began to be called “French polishing.”
By the late 18th century, a lot of furniture was being finished with French polish, preferring to the previous oils and waxes. Fine furniture and musical instruments like pianos, lutes, and guitars had French polish finishes. French polishing is an extremely labor-intensive and time-consuming process. Therefore, with the introduction of nitrocellulose spray technology, French polish was abandoned by the 1930s.
Types of French Polishes
The name “French polish” alludes to any polish that contains shellac and alcohol. More specifically, French polish comprises of a mixture of shellac dissolved in industrial alcohol.
The commonly accepted ratio to make French polish is two parts shellac to sixteen parts of alcohol. We refer to the different concentrations of French polish as “liquid cuts.” You can get heavier or lighter liquid cuts by varying the concentration of alcohol in the mix.
The color of shellac can vary from pale orange to dark brown. French Polish looks its best on dark and light woods to achieve a medium-brown tone with more orange. We use button polish to achieve this color tone. With light-colored or bleached wood, we use white French polish, which looks milky or transparent.
Preparing a Surface for French Polish
An essential aspect of French polishing is surface preparation. French polish is quite sensitive to imperfections and blemishes and will show up immediately under French Polish.
You must clean and sand a wooden surface thoroughly before applying French polish. Suitable surface preparation is a crucial stage in applying French polish, and there are many aspects involved.
Fine steel wool and spirit are useful for getting rid of grease and wax from the surface. If the surface is badly damaged, you may need to use a paint remover or varnish remover to clean it. In the case of stubborn stains, you may need to apply wood bleach.
If the wood shows open grains, but you desire a mirror finish from French polish, you will have to apply a filler. Next, you need to “cut back” the surface using fine glass or garnet paper. In case you want to change the color of the wood, you will have to stain it before applying the French polish. You can mix the wood filler and stain, to complete both dyeing and filling the wood surface in a single operation.
You can only stain wood to a darker color than the existing one. If you require a lighter shade, you need to apply wood bleach to make the wood lighter, and then darken it to the exact shade required.
It is important to note that if you have used a wood stopper to fill holes and cracks in wood, it will always show up through the polish. You can paint a grain-like pattern over the affected areas to somewhat disguise the flaws.
So, the preparation of a wooden surface needs as much skill and technique as applying French polish to the surface, if not more.
How to Apply French Polish
Now that your surface is ready, you can finally apply the French polish. But first, you need to make a rubber. Moreover, you need to know how to use a rubber. Once done, we have outlined the steps required to apply French polish.
Preparing a French Polishing Rubber
To prepare a rubber for French polish, you need to wrap some lint-free cotton cloth around a piece of cotton waste. Take a square piece of cloth about 4” X 4” and wrap it around the cotton rag to form a pear-shaped pad. The base of the pad should be clean and smooth. You can vary the size of the rubber according to your preferences and the size of the job.
How to Use the Rubber
Hold the rubber in your dominant hand and pour a bit of French polish into the rubber so that it soaks into the cotton waste. Do not apply the liquid directly on the rubber face. Now, squeeze out any excess. Ensure that there is no excess liquid in the rubber, which will produce unsightly ridges on the wood’s surface. Your rubber is now ready to apply to the surface of the wood.
We call the first application of French polish “fading up.” You move the rubber back and forth over the wood, ensuring to cover the entire surface. It serves to seal the surface for the subsequent coats.
You have to use a circular and figure-eight motion for making further applications. Whatever direction you start with, ensure to finish along the grain. Do not stop the rubber midway, because it will create a mark as the alcohol acts on the previous coatings.
As more layers get added on, your rubber may not slide as freely as before. This issue can be resolved by rubbing a bit of boiled linseed oil to the rubber base with your finger.
The Hardening Stage
After every four or five coats, you can leave the surface to harden for a few hours. Once set, you should rub the surface with 320 grit sandpaper or 0000-grade steel wool. Follow this by wiping with a dry cloth to remove the dust and debris before applying the next coat.
Once you achieve an adequate layer on the wood’s surface, you can start “spiriting off,” which helps you achieve a high-gloss finish. You need to use a new rubber for this stage.
First, use a mixture of shellac and methylated spirit in a ratio of 2:1. Once this layer dries, apply a mixture of shellac and alcohol mixed in a proportion of equal parts each. Use quick, light strokes, and you will have to rub down any blemished spots.
Burnishing the Surface
You may not always need a high-gloss mirror finish. Sometimes, a lower level of sheen will be sufficient. A French polish finish does not have to be a high gloss mirror finish every time, sometimes you need a softer grade of sheen. To get such results, you need to rub the surface with ultra-fine steel wool after the wood’s surface has hardened. Then, you can apply a wax polish to make the surfaces shine as required.
As we conclude, we can infer that applying French polish is a process where you will get your hands dirty. The process is both messy and time-consuming. And, it is by no means a simple process. You have to know what you are doing. Nevertheless, if you are ready to make an effort, spend the time, and you have adequate knowledge, the results you get are worth the effort.