Methylated Spirits: Is it the Best Solvent for Shellac?

Methylated spirits from England.

 

A woodworker friend called wanting to know where he could buy some methylated spirits. He had just read in a book that it was the best solvent to use with shellac. So I asked him if the book he was referring to was from England, to which he answered that it was.

This term has caused much confusion in the U.S. It’s often misinterpreted here as methanol (methyl alcohol) because it sounds like it. But it’s not. It’s actually British for denatured alcohol.

By breaking the term down it’s easy to understand the correct translation. First, spirits is British for ethanol (ethyl alcohol). It’s the stuff you drink when you go to a pub. The problem with using ethanol for dissolving and thinning shellac is that it’s quite expensive (think Everclear that you buy at the liquor store). So to reduce the cost, which is largely the result of taxes, some methanol is often added to make the ethanol poisonous and therefore not taxed as liquor. The ethanol spirits have been “methylated.”

There are quite a few terms used by British woodworkers and finishers that are different from those used here (some of which I mentioned in my post on French polishing terminology on Jan. 30.) Be aware of this if you are reading something from over there.

So, to answer my question in the title, I’ve not noticed a difference in the dissolving or thinning power of the alcohol used. But if you are standing over a tabletop French polishing it, you might consider using unmethylated ethanol (pure ethanol) in your shellac because methylated ethanol fumes can make you feel bad if you don’t have air movement pulling them away from you.

– Bob Flexner


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7 thoughts on “Methylated Spirits: Is it the Best Solvent for Shellac?

  1. Bob FlexnerBob Flexner Post author

    I doubt there are any denatured alcohols that are really 100% alcohol. They all usually contain some water. I would think the 190 proof will work just fine. You’ll know there’s a problem if the finish blushes (turns white) on a dry day as you’re applying it.

  2. Sullivans Papa

    I read somewhere that (denatured) alcohol was made poisonous so that people wouldn’t drink it and ruin their livers, which I guess was pretty prevalent at some point in time.(?)

    1. Bob FlexnerBob Flexner Post author

      It’s made poisonous to avoid the liquor tax. Compare the price of denatured alcohol with Everclear at the liquor store.

  3. kaw-liga

    Up here in Canada you can only seem to get methyl hydrate. I heard they banned denatured alcohol a while back. At one place you can get shellac thinner for a steep price.

    1. Bob FlexnerBob Flexner Post author

      I don’t know why the shellac thinner should be so expensive. One thing to keep in mind is that you could always use Everclear or an equivalent brand for thinning shellac.

  4. Neitsdelf

    Here in Michigan we can only get about 75% ethanol products (151 proof). Even if I dig up some 95% (190 proof) stuff, will the extra 5% water be a problem? The denatured/methylated alcohol products seem to be 100% alcohol.

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