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Thread: alcohol for thinning shellac

  1. #1
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    alcohol for thinning shellac

    Can someone tell me if denatured alcohol can be used for thinning shellac, or is it different from "wood alcohol" which is the recommended product.

  2. #2
    You mean like the denatured alcohol in the SLX cans (or whatever brand)?

    It works fine for dissolving and thinning shellac.

  3. #3
    DNA (Ethanol) is fine.

    Isopropyl alcohol will also work.

    (edit: rubbing alcohol is largely IPA, but contains additional water which I've been since counselled can affect the final result).
    Last edited by Prashun Patel; 12-08-2010 at 8:28 AM.

  4. #4
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    wood alcohol = methyl hydrate and HD carries it.

  5. #5
    Prashun, Please do not encourage folks to use rubbing alcohol for shellac. It has too much water in it and does not produce as good a result as DNA. Note that there is a differrence in quality of the brands of DNA. The best (read safest) have the lowest level of methyl alcohol in them. Methyl alcohol will attack the optic nerve after prolonged exposure and/or high concentrations in the air.
    Dave Anderson

    Chester, NH

  6. #6
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    Quote Originally Posted by Dave Anderson NH View Post
    Prashun, Please do not encourage folks to use rubbing alcohol for shellac. It has too much water in it and does not produce as good a result as DNA. Note that there is a differrence in quality of the brands of DNA. The best (read safest) have the lowest level of methyl alcohol in them. Methyl alcohol will attack the optic nerve after prolonged exposure and/or high concentrations in the air.
    I think denatured alcohol typically contains about 10% methanol (aka wood alcohol) in what otherwise is ethanol. According to wikipedia (always a reliable source ) some manufactures instead use other chemicals like acetone, butanone, denatonium or, ironically, isopropyl alcohol (rubbing).

    If you really want to get fancy, TFWW sells water free denatured alcohol. They only use 1/2% denaturant.

    When we were testing this solvent against other premium shellac solvents that typically also contain amounts of methanol or isopropyl alcohol and are not all ethanol we assumed that there would be little difference in performance. Much to our surprise we found that shellac dissolved in the pure ethanol seemed to dry faster, harder, and with a higher sheen.

  7. #7
    Quote Originally Posted by Dave Anderson NH View Post
    Methyl alcohol will attack the optic nerve after prolonged exposure and/or high concentrations in the air.
    Guess a lot of people found that out in the 20s? Have they always used the same denaturant? I remember reading that people were getting sick and going blind during prohibition.

    Do you know which of the commonly available versions/brands has the least methyl alcohol in it?

  8. #8
    Personally, I use Graves XXX or Everclear. I don't use so much that I'm bothered by the cost difference. It's far more pleasant to work with than DNA IMHO.

  9. #9
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    Quote Originally Posted by John Coloccia View Post
    Personally, I use Graves XXX or Everclear. I don't use so much that I'm bothered by the cost difference. It's far more pleasant to work with than DNA IMHO.
    Not to mention the sides benefits if you have a can of coke or fruit juice handy............
    When I started woodworking, I didn't know squat. I have progressed in 30 years - now I do know squat.

  10. #10
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    Quote Originally Posted by Darius Ferlas View Post
    wood alcohol = methyl hydrate and HD carries it.
    Make sure you have good ventilation and/or a solvent mask.
    Paul

  11. #11
    Dave, I'll defer to your experience, but will share mine:

    I routinely use Isopropyl Alcohol as a solvent for shellac. I have not experienced hardness or blushing problems. The only thing I have noticed is that it expectedly dries a little slower than ethanol which has made it a little more friendly to pad for me.

    On another point, I know from my work that ethanol will absorb 5% water from the atmosphere. 'Water free' ethanol can't remain that way for long without a lot of effort.

  12. #12
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    I use a fair amount of shellac and use DNA.

  13. #13
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    Thinning shellac - beware

    See Joel's blog on some of the safety issues:

    http://www.toolsforworkingwood.com/M...tml&BlogID=239


    Steve

  14. #14
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    I buy and use 500ml bottle of 99.5% ethanol from pharmacy. I initially started off using denatured alcohol that was available locally, but it contained 34% methanol and I just didn't want to be soaked in that vapor for hours at a time.

    It's bit pricey, but that's as good as alcohol can get.

  15. #15
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    Quote Originally Posted by paul cottingham View Post
    Make sure you have good ventilation and/or a solvent mask.
    Thanks for the reminder. I should have included in my post.
    I use a serious mask, proper clothing and rubber gloves too, since Methyl Hydrate is also absorbed through skin.

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