Quora: What is French polishing?
Ben Kleschinsky, studied at Nashua Community College
French polishing is actually a very interesting method that the French mastered in the 18th century. French aristocrats and immigrants brought their craft over to America during the American Revolution, where it was made extremely popular during colonial times until it fell out of favor in the 20th century. We don’t polish furniture like this anymore, although you still can it is more difficult and dangerous.
French polishing involves the use of shellac, which are made from the secretions of an Iac bug. Today there is only one brand in the United States that sells pre-mixed shellac solvent, and that is Zinsser which isn’t too amazing and I will explain.
French polishing originally involved soaking shellac flakes in moonshine (grain alcohol), and soaking wool fibers wrapped in a linen soaked rag in the shellac solvent in a circular motion. Some furniture making would take hours or months to build up layers depending on the alcohol source. As you build up layers, it builds up to a mirror like finish that some say is unlike any modern technique.
French polishing went out of style in America for one reason and one reason only, because of the prohibition of alcohol. In the 1920’s furniture makers had to switch to denatured alcohol. Shellac finishes are dependent upon alcohol. The higher proof of alcohol you can use the better result you will get. Government started dumping methanol in all forms alcohols which is extremely dangerous to consume and inhale. However when prohibition was lifted the methanol stayed in non food grade products. This is why stains and varnishes became popular in the 20th century. Not many realize this strange history.
In the modern age of furniture making, prohibition laws are still in effect. The ATF still requires that methanol be put in all non food grade alcohols, which don’t make the best mixtures anyways for french polishing. Today in stores if you want to buy denatured alcohol, it will contain methanol which is what you are breathing in commercial shellac products. The percentage of methanol in denatured alcohol has increased even more in recent years. The solvent in the finish evaporates so you will breathe in a lot as you are laying it down for hours on end. This makes it extremely unpopular and toxic to use.
The original alternative is 190 proof moonshine alcohol, but states across the country are starting to ban the use of brands like Everclear because of it’s status as a party drug. As of 2020 New Hampshire, Nevada, California, Ohio, Florida, Maine, Maryland, Michigan, Hawaii, Iowa, Minnesota, and North Carolina make it illegal to purchase 150 and 190 proof. In the other 38 states you have to be 25 years or older to purchase 190 proof. You can buy un-denatured ethyl alcohol but you need a permit of reasonable request in those states. If you’re not a science lab or established business it’s a lot more difficult for a person off the street to obtain. Websites won’t ship to banned states either.
This sucks for hobbyists like myself if you live in one of these states, because we are forced to travel out of state to get the best. Ask many enthusiasts who still try to perfect the art of French polishing, and they will tell you that 190 proof gives them the best results. Especially for someone like myself who works in a basement every day, methanol which is also in gasoline would be inhaled into my lungs. This has led many wood polishing enthusiasts to hoard Everclear. That’s why everyone switched to lacquer and polyurethane finishes. It’s just a lot easier to deal with and legal. I’ve attached a very interesting article for you to read about it.
You can find various tutorials on YouTube on how to get started. It’s still widely practiced and popular throughout the world outside of the United States. For the best results where you have more control, you make your own shellac tinctures from 190 grain alcohol if you can find it. Also a small tip. Only apply darker shellacs in no more than two layers, and then switch to lighter shellacs for the remaining to avoid brush marks.
Here are some more shellac eye candy;
Edit 9/23/19; Post updated to showcase that French polishing is still commonly used around the world outside of the United States.
If you are a hands-on kind of guy — and don’t like the idea of being replaced by a robot — this could be a rather lucrative endeavor. But be sure to relocate to the right State, or relocate outside the United States.
And someone needs to shut down all those legacy State bureaucracies. Its almost impossible to repeal all the wicked laws out there — nobody even knows all the laws that were created since Prohibition — but you can at least cut them off at the knees, by removing any kind of enforcement or punishment for breaking said laws