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Home How To Finishing Dewaxing Shellac

Dewaxing Shellac

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Certain grades of shellac come with wax incorporated into them, more so in the shellac that is less refined and darker in color. I have no idea if this shellac is naturally occurring (although I suspect it is) and it really doesn’t matter. What I can say with some degree of certainty, is that unless the package specifically says the shellac is dewaxed, there will be wax in the product. So, "who cares," you may ask?

Sources all over will tell you that the wax in shellac creates an adhesion problem when used under other finishes. That means, if you use it as a seal coat under polyurethane, the poly may not stick to it. As a sealer, I have used shellac with great success but I have never seen this problem. One reason may be that I dewax it before use.

Actually, I haven’t ever heard of anyone having adhesion problems, but I have read that it is a problem from a number of sources that are widely known as experts in the field of wood finishing. Those same experts tell me that the wax is supposed to make the dried shellac film softer and more susceptible to water damage. Again, I’ve never had this problem but, if you are anything like me, you’d rather be safe than sorry.

Besides, dewaxing shellac is easy. The shellac resin you want is soluble in alcohol but the wax isn’t so it becomes a simple matter of separation. Here is my procedure for doing it but don’t be in a hurry. You need to plan ahead as, for best results, this is not a one day process.

    1. Shake: After mixing the shellac and alcohol in the proper proportions for your cut, place a lid on the container and shake it often, and vigorously, during the first hour.
    2. Relax: Let the mixture sit, completely undisturbed, in a dark place for twenty four hours at least. You can let it sit a little more if the top layer of shellac isn’t perfectly clear. If it doesn’t clear completely, you may want to get new flakes.
    3. Filter: The next day you will see the clear, dewaxed shellac layer on the top, with the insoluble wax layer laying at the bottom of the jar. The wax should be murky looking while the shellac should be clear as water. Using a funnel with a coffee filter in it, pour the clear layer through the filter into another container, being careful not to stir up the wax in the bottom. You don’t want wax in the coffee filter as it will clog the filter making the process take a very long time. I discard the wax by poring it into the dirt in the back yard. Once the alcohol is evaporated I scoop up the dirty wax and throw it in the garbage.

That’s it. For more information see my recipe for French polish. This doesn’t sound like a scientific process (although it is) but it effectively removes the wax from any shellac. I learned the process by reading the works of George Frank. He was one of the last of the true, old time finishers – trained in traditional finishes during traditional times. Thanks George, you’re a real inspiration.

If you can pick up 88 Rue de Charonne, Mr. Franks’ book, do so - I highly recommend it. It was published by Taunton in the early 1980’s and has since gone out of print. You’ll probably have to try a used bookstore to get it but it will be worth every penny.

© 2011 Howard Ruttan - inthewoodshop.org

 

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