alcohol for thinning shellac

[Acharya Kumarswami]

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.

[David Weaver]

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

It works fine for dissolving and thinning shellac.

[Prashun Patel]

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).

[Darius Ferlas]

wood alcohol = methyl hydrate and HD carries it.

[Dave Anderson NH]

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.

[Andrae Covington]

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 :rolleyes:) 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.

[David Weaver]

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?

[John Coloccia]

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.

[Kent A Bathurst]

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............

[paul cottingham]

wood alcohol = methyl hydrate and HD carries it.
Make sure you have good ventilation and/or a solvent mask.

[Prashun Patel]

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.

[glenn bradley]

I use a fair amount of shellac and use DNA.

[Steve Kirincich]

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

http://www.toolsforworkingwood.com/Merchant/merchant.mvc?Screen=NEXT&StoreCode=toolstore&nextpage=/extra/blogpage.html&BlogID=239


Steve

[Sam Takeuchi]

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.

[Darius Ferlas]

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.

[Chris Friesen]

You can get 99% pure isopropyl alcohol by the gallon at farm supply places. It works, but takes longer to dry and longer to disolve shellac flakes.

Ethyl alcohol is the usual solvent for shellac, but I've only been able to find it reasonably priced in 500ml bottles at the drugstore (and you have to ask the pharmacist for it, it's not on display).

[David Weaver]

Chris, how much is it at the pharmacy?

I see it in quarts online for like $35.

[Marco Cecala]

Somebody did a test and found that Startex and Sunnyside have less denaturing. I agree with John and have recently started using Ever Clear for French polish. Luthiers use it, and I want the same finish. I find I get no fogging, and it dries faster and harder than denatured. Yes it costs more. Having to re-do a finish is not cheap either.

[John Coloccia]

Somebody did a test and found that Startex and Sunnyside have less denaturing. I agree with John and have recently started using Ever Clear for French polish. Luthiers use it, and I want the same finish. I find I get no fogging, and it dries faster and harder than denatured. Yes it costs more. Having to re-do a finish is not cheap either.

The fogging is exactly why I switched. I kept ending up with a funky film that I just didn't like. And, as someone mentioned, it'll make a dandy lemon drop.

[Joel Goodman]

I assume you mean the Everclear 190 which is I guess 95% alcohol. Can you believe it's not legal to sell in California --- an we have "medical" marijuana!

[John Coloccia]

I assume you mean the Everclear 190 which is I guess 95% alcohol. Can you believe it's not legal to sell in California --- an we have "medical" marijuana!

Yes, exactly. Actually, I'm usually using Graves XXX because that's what the local liquor store carries but most are familiar with Everclear and it really is the same thing.

Good luck dissolving shellac in marijuana...
:p