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 I'll soon be making my first attempt at French polishing and, to that end, I ordered shellac flakes from Wood Essence here in Canada. With the flakes came a note titled "Alcohol for Shellac Solutions". It contained the following paragraph:

"It is difficult to obtain so-callled denatured alcohol (ethanol) [in Canada], however, you will likely find a different type of alcohol available in most point supply or hardware stores, referred to as "methyl hydrate". Methyl Hydrate is essentially methanol (wood alcohol and extremely poisonous). It is frequently labeled as being suitable for dissolving shellac, however, methanol has a very fast evaporation rate and when used in a shellac solution, craftsmen may find the solution very difficult to work with. The problem is that the shellac sets up so quickly, that the shellac won't flow out properly on the surface. This is particularly noticeable when attempting to brush a shellac finish, where brushing back over an area or attempting to brush on adjacent areas, causes the shellac to "stick" and results in extensive brush marks or "burned" areas."

I know that French polishing is not brushing and I noticed in the youtube guitar building series, Steve uses Methyl Hydrate in his French Polishing and it seems to be working OK. I'm wondering if others can recommend it as well. It is indeed, the most available stuff that I can find.

Thanks,
Pat

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There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

Sorry I have no experience with it, but so you have pure grain alcohol up there in Canada? Everclear or something similar? They won't be selling it in any hardware store I know of, though.
It works exactly like Denatured Alcohol, but it is much safer. Less chemicals to seep into the skin. It is "non-toxic" as far as french polishing goes, but it still has the potential to kill ya dead if you drink too much of it.
-j.

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“If God dwells inside us like some people say, I sure hope He likes enchiladas, because that's what He's getting”
-jack handy

Yeah, but you die with a smile on your face, and bubbles around your head! 

_________________
Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

I would stay away from anything that has a high concentration of methanol. Very poisonous!! If you can't get Everclear, Lee Valley sells in Canada what appears to be repackaged Behkol, i.e. ethyl alcohol and isobutanol as a denaturant. Behkol works well for FP.

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I think Methyl hydrate is used in diesel tanks to evaporate any excess moisture or water that has accumulated in the fuel.. thats where Ive seen in used anyhow,,, nasty stuff -
But not to worry, theres usually a thump pot, in every town if you look into it ;-)
If I were you Id go to http://homedistiller.org/forum/
Very nice guys there and usually youll find someone who can produce 95% alcohol pretty near to where you live - if you look around, and ask about..
Lots of Canadians on there,,, but lots of Aussies and Americans etc too
Cheers
Charlie

Pat-
Methyl hydrate is one option; there are others.
The simplest option, if you're ordering stuff from LeeValley anyway, is probably to buy their solvent- it's expensive, but you don't need very much to FP a guitar. It's a mix of ethanol, propyl acetate, isopropanol and isobutanol.
In some provinces you can buy grain alcohol (ethanol aka Everclear in the US) at the liquor store- here in BC you need to get a special permit before you can buy it. If you're close to the border, buying Everclear in the US is a possibility, but it's not sold in all states.
Isopropanol (isopropyl alcohol) works for FP, though it's slower to dissolve flakes and slower to evaporate as well. Farm supply places sell this as veterinary rubbing alcohol at about $25/gallon. You can also buy it in the drugstore, though the stuff repackaged for humans is more expensive.
Some drugstores sell an ethanol-based rubbing alcohol, which is a good bet.

I keep methyl hydrate around for cleaning up epoxy and other jobs. It's also handy if you have to remove/redissolve shellac/FP, clean brushes, etc- you don't want to use the expensive stuff for that. However, like most solvents, it's toxic so you should work outdoors and/or wear a good mask with organic vapor canisters.
Methanol toxicity
I try to keep solvents off my skin- buy a box of thin nitrile gloves; it's cheap insurance.

If you transfer your alcohol(s) of choice to small containers with flip tops or similar spouts, you can minimize the amount that gets into the air. You don't want any of this stuff circulating in your household air supply- with tighter homes and winter weather, you can be 'rebreathing' the stuff for a long time.

Cheers
John

I have used methyl hydrate so far. Mario also reported using that. The quantity used is very small if you wear a rubber glove and vent the space, there is no problem with poisonning. Also, the eliminating ingredient for methanol is ethanol. So dring a little wine or beer while french polishing and you will be Ok   
You can get denaturated alcool herebut it is not cheap.


I wonder if a mix of methanol and isopropyl (rubbing alcool) would match the evaporation rate of ethanol?

[QUOTE=Alain Lambert]   The quantity used is very small if you wear a rubber glove and vent the space, there is no problem with poisoning.

[/QUOTE]

Alain- I agree - for FP with methyl hydrate , where the exposure is low, I wouldn't worry about using any extraordinary safety precautions (outdoors,respirator)- my comment was about using methyl hydrate for cleaning up larger epoxy spills, cleaning brushes, etc. I removed a shellac finish from an older project guitar with methyl hydrate (and lots of paper towels) and did that in the garage with the window open, rather than inside.

Cheers
John

It's pretty well all I use. The LeeValley stuff(Behlen's actually) stinks to high heaven's. I brought-in some denatured before, and found it no better than methyl and also stank....

[QUOTE=Alain Lambert] I have used methyl hydrate so far. Mario also reported using that. The quantity used is very small if you wear a rubber glove and vent the space, there is no problem with poisonning. Also, the eliminating ingredient for methanol is ethanol. So dring a little wine or beer while french polishing and you will be Ok   
You can get denaturated alcool herebut it is not cheap.


I wonder if a mix of methanol and isopropyl (rubbing alcool) would match the evaporation rate of ethanol?

[/QUOTE]
I would stay away from the rubbing alcohol because it has a high percentage of water in it and sometimes other additives.

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Guitars, guitars and more guitars.

All alcohol is hygroscopic

Thanks for the responses. Since it was only a few dollars, I did buy a bottle of the methyl hydrate but I will probably also buy the stuff from Lee Valley so I can compare the two. I make the observation however, that the cost of the flakes and the Lee Valley solvent together add up to more than a quart of Zinsser's which I gather from this forum would be just as good.

Pat

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

[QUOTE=FishtownMike]
I would stay away from the rubbing alcohol because it has a high percentage of water in it and sometimes other additives.[/QUOTE]

I just checked my bottle of veterinary isopropyl rubbing alcohol- it's 99%. Perhaps some drugstore products have additives and water- check the label.
As Mario says, most alcohols will absorb water from the air to some extent. Distilling ethanol from a mash will never get more than 95% because ethanol and water from a low-boiling azeotrope at the 95/5 ratio. (You only get 100% in the blues song....)

Now I remember ( the stink) why I still have a full can of LValley/Behlens solvent on the shelf.

Cheers
John

Most rubbing alcohols sold at least here in the states are only 70 to 80% alcohol and 30% purified water.

_________________
Guitars, guitars and more guitars.

The bottle I have of Isopropyl alcohol is marked 99%

Evaporation rates compared to Nbutyl alcohol are:

Methanol   5.9
Ethanol    3.3
Isopropyl 1.5

So if looks as methanol evaporate about twice as fast as ethanol and isopropyl alcohol at around half the speed of ethanol.

It is probably over simplistic, but a mix of 1:1 may be close to the evaporation rate of ethanol.

I didn't think 99% alcohol was a possibility.  It was my understanding, subject to correction, that 95% was pretty much the highest concentration that was stable.  If you open 99%, it then stabilizes at 95%, as it sucks moisture out of the air.  Maybe isopropyl is different.

_________________
Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Methyl Hydrate will work but for a first time french polisher I would stay away from it both for it's toxicity and it's fast flash time. Also you do not want to use isopropyl rubbing alcohol.

Everclear (pure grain alcohol) would be a better choice for a first timer. actually better choice than denatured alcohol.

Pre- prohibition here in the states the alcohol available at your local general store or hardware store used for solvent purposes was grain alcohol. Then during prohibition all potable alcohol was outlawed, but we still needed an alcohol based solvent. So the federal government had the bright idea to poison menthol alcohol that was sold as a solvent. For some stupid reason after prohibition the feds decided it made more sense to the Feds to keep it poisoned (denatured) rather than having hardware stores licenced to sell it in a form that could be considered potable.

Methyl Hydrate will work but for a first time french polisher I would stay away from it both for it's toxicity and it's fast flash time. Also you do not want to use isopropyl rubbing alcohol.

Everclear (pure grain alcohol) would be a better choice for a first timer. actually better choice than denatured alcohol.

Pre- prohibition here in the states the alcohol available at your local general store or hardware store used for solvent purposes was grain alcohol. Then during prohibition all potable alcohol was outlawed, but we still needed an alcohol based solvent. So the federal government had the bright idea to poison menthol alcohol that was sold as a solvent. For some stupid reason after prohibition the feds decided it made more sense to keep it poisoned (denatured) rather than having hardware stores licenced to sell it in a form that could be considered potable.

[QUOTE=WaddyT] I didn't think 99% alcohol was a possibility. It was my understanding, subject to correction, that 95% was pretty much the highest concentration that was stable. If you open 99%, it then stabilizes at 95%, as it sucks moisture out of the air. Maybe isopropyl is different.
[/QUOTE]
This brings back (foggy) memories of PhysChem 301 in 1967....some lurking PhD in Chemistry should jump in here instead of me.
There are thousands of different alcohols-so you do have to be specific.
The 95% ethanol 'limit' doesn't have much to do with the alcohol 'sucking' water out of the air. Chemists regularly use 99%+ ethanol in the lab. You need to understand the idea of azeotropes (mixtures) to get a handle on this. If you are distilling ethanol from an ethanol/water mixture (fermented mash), the lowest boiling fraction (the most volatile) is the azeotrope with 95% alcohol and 5% water. You can increase the alcohol concentration by passing that fraction through a dessicant. You can also add a third component to the mix- it used to be benzene- so that you get an azeotrope with a higher % ethanol when distilling.
For isopropanol, the situation is different, and the 'standard purity' is 99%- it's synthesized from propylene gas, which is a byproduct of petroleum refining. BTW, some ethanol is 'denatured' with isopropanol to make it undrinkable.

Cheers
John

I picked up a bottle of ethanol Rubbing Alcohol at the drugstore- they were keeping it behind the counter.
It's an expensive way to get ethanol if you have access to lab alcohol or Everclear, but might be useful for some folks. It definitely smells better than the Behlens.
Contents:
95% ethanol,water + some additives (camphor, diethyl phthalate, diethyl benzyl benzoate) to make it unpalatable.

I'm in BC, Canada- your local availability may well be different.

Cheers
John

But do you really want camphor or whatever in your shellac? Methyl hydrate is already poisonous, so they don't add anything to it. It's just pure methyl alcohol. And a little water doesn't hurt; I've used the same gallon of methyl overt he course of a year(a gallon will sometimes last over a year) and i have forgotten to re-cap it a few times, so it definitely had absorbed water. No harm, no foul shellac.

 And what did "they" have centuries ago when they French polished all the great furnitures and instruments? You think they were as fussy as y'all are being?

Maybe my battle yell for 2008 will be "STOP OVERTHINKING EVERYTHING!!!!"



If you really want to be safe, make yourself a batch of water based shellac. Easier still, buy it(Target Coatings makes some)








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Sorry, Mario- I forgot there is only one way to do things.

There isn't only one way to do things, and we've all offered our opinions here, and that's all good, but the degree of minutia we get into is nuts.

Keep it simple.... One doesn't need a chemical degree to mix up shellac. and for many of us(for example those in Ontario) denatured is unavailable, and Everclear is non-existent(nothing over 40% alcohol, please and thank you says the Gubmint)