If you have seen a well applied French polished shellac finish, then you may have experienced the clarity, depth, and richness that synthetic finishes can not duplicate, and more importantly the unique, woody, open sound that it brings to a guitar’s voice. But when you’re starting out, the technique of French polishing can be difficult if you don’t have the proper instruction or if your just going by trial and error like I was in the beginning. When I was first starting to French Polish my guitars I knew it was what I wanted for my guitars, but I was struggling with applying it. I could not deliver a guitar with anything but a perfect finish, so I made up for my lack of French polishing knowledge and technique with a lot of persistence, sweat, tears, and many many hours of working to get it just right and fix my mistakes. Even though I was producing a very nice finish, I was feeling really stuck because of the difficulty and frustrations I was encountering when french polishing each guitar. That is until one fateful day when I was invited by the famed French polishing master Eugene Clark to come to Washington and learn from him one on one. It was a life changing time and I will forever be grateful to Eugene for his help, guidance, and friendship. His influence literally transformed the way I think about and build my guitars, not just the finishing, but all aspects of the design and the instrument itself.
The French polishing technique I learned from Eugene is the basis of the technique I will be talking about in this series and that I teach in my online French Polishing course. If you are a Luthier’s edge member or if you’re enrolled in The Art Of French Polishing video course, you can log in and download the new eBook: Introduction To French Polishing which contains this entire 3 part series plus 3 bonus demonstration videos.
What Is French Polishing?
The term French Polishing refers to the art of using what is know as a pad, rubber, or muneca constructed usually of cotton cloth wrapped around some type of core material to apply a finish to a wood surface by rubbing. So the term French polishing is really talking about the physical act and technique of applying the finish rather that the type of finish itself.
The most traditional french polished surface is different from what we typically do on guitars today. According to my teacher Eugene Clark, The original craftsmen doing french polishing on furniture would simply fill the pours of the wood and leave only a slight coating of shellac on the surface of the wood.
Today professional French polishers will usually build the finish on top of the surface more in order to give it a high gloss look and to increase durability. Even with a slightly heavier build, a French Polish finish is usually far thinner than any synthetic type of sprayed or brushed finish which is one reason it lets the voice of the guitar and sound of the woods come though so clearly when the guitar is played.
A Little History Of French Polishing
The technique of French polishing with shellac resin was refined in France during the 18th century and was considered the highest quality wood finish for fine furniture and musical instruments such as pianos and guitars. With the introduction of faster and cheaper nitrocellulose spray technology staring around the 193o, many factories abandoned the technique. 1
There are three main material types commonly used for French Polishing guitars; shellac resin, alcohol, and oil. In the sections below we will be looking at each component and the properties and functions they serve in the French polishing system of application ans the varnish formulation itself. If you have read any of my book on guitar making, you may already know that just understanding the step by step directions isn’t enough, I want to know WHY. I need to understand how things work and I am betting your like me in that regard if your reading this right now. So we’ll be talking about what materials are commonly used or course but more importantly we’ll be looking at why and what purpose each ingredient serves to make a better looking and sounding finish for our guitars.
The most commonly used material to be applied with the French polishing technique is shellac. Shellac is a natural resin that is made by the Lac Beetle when it feeds on the sap of several different types of trees in India and Southeast Asia. The Lac beetle forms a shell in which it will lay eggs which is made of Lac. The process of harvesting and collecting lac begins as the trees are infested with lac beetles who build their shells on the branches of the tree which is then scraped off with a hot knife and collected.
The rough material collected for the initial harvest is called stick lac, because it contains a lot of sticks and dirt, dead bug bodies, etc. The stick lac is then refined in a number of ways; It can go to a factory for industrial processing to be carried out in order to purify it into the final thin flakes that it will be sold in for various commercial and other uses.
The stick lac can also be purified by hand by initially being roughly filtered into what we know as seed lac. As you might guess by the name,the seed lac form resembles tiny seeds of resin. At this stage there is still a good amount of wood chips and bugs in there, but it is usable for French polishing after being dissolved and filtered for use.
The next stage in handmade shellac is to take the seed lac and fill long cotton bags with it. Then the bags are held over a fire to be heated and the hot shellac is squeezed through the fibers of the cloth bag dropping large drops of shellac onto the ground that resemble large buttons. I have read in other places that the buttons may also be made by scooping it out with a spatula onto a plate and then reheating it again to smooth the surface. This type of shellac is know as “button lac”.
Button lac is my personal favorite type of shellac to use because it is in a very raw and un-tampered with state. But most importantly , because it was heated more, it forms a tougher more impact resistant coating due to the resulting polymerization that occurs from the heating process.
Using other hand methods the resin can also be dissolved in alcohol , filtered, and them poured out onto huge pans to dry letting the solvent escape. It can even be stretched out into a thin sheet while still hot which is common in hand made shellac production. Once the thin sheet of shellac resin has hardened it can be shattered and broken into the flakes we commonly see when purchasing flak shellac.
Today most commonly the flake shellac is commercially produced in factories using a variety of different methods for dissolving and filtering, some of which compromise the gloss, durability, and purity of the final flake shellac. I try not to use any commercially produced shellac if possible.
Colors Of Shellac
The stunning and unique color of different shellacs are a result of several different factors. One of the contributing factors in producing the many beautiful colors of shellac is the season in which the shellac was harvested. A summer shellac, known as Bysakhi will be a very dark and intense color while the winter harvest called Kusmi will be more caramel colored and much lighter.
It is very sad to me that with the amazing verity of shellacs available, I rarely see people using the darker shades of shellac. I feel that for the guitar maker it is essential to use the darker colors of shellac. Using at least some color will unify the instrument and help it to look like a complete object rather than a bunch of parts put together.
It is really not that hard to use darker colors, once you get your technique mastered to the point that you are applying a very even coat of finish on the guitar. There are some guidelines that should be followed though, to ensure that your guitar will look as beautiful as possible with a darker colored shellac finish.
Alcohol And Oils For French Polishing: Introduction To French Polishing Part 2
In the Introduction To French Polishing Part 2 we will be exploring the other components of the shellac varnish used for French polishing, Alcohol & oils. Different types of alcohol can have different effects on the shellac and each type of oil has a special purpos as well.
Introduction To French Polishing: Shellac, Oils, & Alcohol – eBook
When learning to French Polish a guitar, having a solid understanding of each component of the finish and what the function of each ingredient is, will set you up for success as you develop your own systems for obtaining a beautiful hand rubbed French polish finish.
- Instant Digital Access
- Understanding Shellac
- Types & Colors Of Shellac
- Types Of Alcohol for French Polishing
- Types & Uses For Different Oils
- Drying Oils
- Non-Drying Oils
- Video 1 – Making the Pad
- Video 2 – Pore Filling Basics
- Video 3 – Basic Technique
- 17 Pages