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| French Polishing Alcohol http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10102&t=863 |
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| Author: | dubell [ Fri Jan 28, 2005 12:41 am ] |
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I am getting geared up to French Polish. What alcohol to you use? Whenever I have mixed shellac in the past, I have used Denatured Alcohol. I don’t want to use this for French Polishing because it is toxic. I went to the State Store (for those of you who don’t know what that is, it’s where PA residents buy drinking alcohol. If you want alcohol, you have to buy it at a state store. Yeah, I know, it’s stupid) to get some ethyl alcohol, but PA is not allowed to sell alcohol that is over 150 proof. Before I get one of my NJ buddies to pick me up a bottle, I want to know what you guys use. I think I can also use Behkol. Thanks, Doug Ubele |
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| Author: | Mike Mahar [ Fri Jan 28, 2005 12:58 am ] |
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For an on-line source try: http://www.beerliquors.com/liquors/grain.htm You'll still have to have a friend in New Jersey get it for you. I've never used this source. They are just what turned up on a google search. |
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| Author: | tl507362 [ Fri Jan 28, 2005 4:04 am ] |
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I'm refinishing my 2nd guitar top and back, and I went from the Zinsser FP in a can to straight shellac flakes. I mixed the flakes with the same brand of everclear 190 proof alcohol that Mike shows above. Worked great! |
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| Author: | dubell [ Fri Jan 28, 2005 4:57 am ] |
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Everclear is about $23 for 750ml (about 24oz). Behkol is about $7 for 32oz. Why don't you use behkol. Is it safe to handle? Thanks, Doug Ubele |
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| Author: | Paul Schulte [ Fri Jan 28, 2005 10:59 am ] |
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Here's a link to what I use. it has no methanol or acetone, I don't know what the de-naturent is but it's low odor. I think the methanol in DA is not good for you and doing FP you get exposed to alot of it. http://www.woodfinishingsupplies.com/shellac_a.htm |
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| Author: | Mario [ Sat Jan 29, 2005 5:18 am ] |
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I use straight methanol. $5/gallon..... No side effects yet, but then again, I'm not drinking it. Don't y'all wear gloves to french polish? IF you do, then the alcohol of choice doesn't much matter. IF you don't wear gloves, well...... |
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| Author: | Dickey [ Sat Jan 29, 2005 5:25 am ] |
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Silly question: Where do you buy methanol? |
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| Author: | Mario [ Sat Jan 29, 2005 6:15 am ] |
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Huh? It's everywhere here. Gas stations, hardware stores, even grocery stores. Most often called "Methyl Hydrate" in Canada and the UK. |
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| Author: | dubell [ Sat Jan 29, 2005 6:39 am ] |
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I plan on using gloves. Touching it is not the concern I have, it's inhaling the fumes. I have never Frenched Polished, but have mixed shellac many times. The alcohol I have used was bought from Home Depot. It is S-L-X Denatured Alcohol. The back of the can says, "USE ONLY WITH ADEQUATE VENTILATION TO PREVENT BUILDUP OF VAPORS....Reports have associated repeated and prolonged overexposure to solvents with neurological and other psysiological damage......This product should not be used frequently or on a regular basis without properly engineered air controlled systems designed to prevent exceeding appropriate TLV." Sounds dangerous to me. WoodFinishingSupplies 200 Proof Denatured Alcohol is made up of: 90% Ethanol 9% Isopropanol 1% Methyl Isobutyl Ketone (MIBK) Because it does not contain methanol, it evaporates at a slower rate. I would think this would cause problems with French Polishing? Thanks guys, Doug Ubele |
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| Author: | Paul Schulte [ Sat Jan 29, 2005 8:14 am ] |
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French polishing is a tricky business. i think I relearn it everytime I do it. I think that no matter what solvent you use you learn to adapt your technique. fortunately F.P. is very forgiving so by the time I am down to the final sessions I seem to have it down. Good ventilation is a good idea, sometimes easier said than done when summers are hot/humid and winters are cold/dry like here in NE. With all that said I would still like to try Everclear and plan to do so if I can find any easily availbale source. The 1% MIBK (MethylIsobutyl Ketone)in wood finishing supplies D.A. is the stuff you really need to look out for in their formula, but at least it's only 1% (thanks for finding that info by the way!). |
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| Author: | Mario [ Sat Jan 29, 2005 8:28 am ] |
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Manufacturers need to write stuff like that on their products to fend off lawsuits. Fumes from alcohol? Get over it.... |
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| Author: | tl507362 [ Sat Jan 29, 2005 3:10 pm ] |
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Another hot tip I just found out about. I'm reading an interesting book "Understanding Wood Finishing" by Bob Flexner, and he has a chapter on Shellac French polishing. He says when you use oil with shellac, you should wait a day to let the oil rise to the surface, then come back and wipe the surface with Naptha. He states that many books say to use Alcohol, but actually, Alcohol tends to loosen the shellac, and you could actually damage the finish. He goes on to say that the reason we still use Alcohol for removing the oil is because that is what tradition has taught us. BUT, back in day, they didn't have solvents like Naptha. So he says, use Naptha, and you won't risk damaging the shellac under the oil. Also he mentions that there are basically 3 types of Alcohol, Methanol(also called methyl or wood alcohol), ethanol(also called grain alcohol) and isopropanol(also called rubbing alcohol). Any of these forms will dissolve shellac, but methanol is quite toxic, and isopropanol contains too much water to be a good solvent. He says denatured alcohol, or just grain alcohol(everclear 190 proof)are the best because it evaporates more slowly and gives you more time to brush or apply it with a pad. Anyway, I thought this was interesting and thought I would share with all of you. |
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| Author: | Dickey [ Sat Jan 29, 2005 3:43 pm ] |
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| Author: | Mario [ Sat Jan 29, 2005 3:58 pm ] |
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I've read the opposite, that methanol produced the hardest final finish for some reason or another... I've been french polishing for about 11 years now, always using methanol, and I've always had a very hard, durable finish. But anyhow, while methanol is indeed toxic, in the real world, that pretty well only applies if you drink it, or pour it liberally on your skin, often. If you wear gloves while using it(as you should, lest you spend the rest of the week trying to wash shellac of your fingers <g>), you won't be in direct contact. I don't believe I've ever read any warnings with regards to it off-gassing in dangerous fashion. Heck, it even smells milder than ethanol. My take is that the warnings are to discourage folks from drinking it, as some still do every now and then(and die from it, too). Anywho, do as you please, but remember that the most dangerous(statistically) chemical on earth is water. The danger is always in the dose... |
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| Author: | Don Williams [ Sun Jan 30, 2005 1:34 am ] |
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I've heard the same as Mario. A friend had an "old timer" teach him about french polish, and the guy told him that Methyl alcohol was the best for french polish for the very same reasons that Mario mentions. They've actually used a dry gas product that was 100% methanol for that. I guess you get it however you can. I've tried that, and indeed, the finish has remained very very hard through the years. Of course it was on a chair not a guitar, but still, it worked great. |
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| Author: | Paul Schulte [ Sun Jan 30, 2005 2:36 am ] |
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For people that live in the warmer climes dry gas is an additive we in the north add to our gas to prevent gas line freeze up in the winter. I think some is methanol and some isopropyl and some a mix of both. Gonna give that methanol dry gas a shot, the price is sure good! |
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| Author: | PaulB [ Sun Jan 30, 2005 9:16 am ] |
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I, and another R&D chemist I worked with, had to do a hazard assesment (actually we insisted), on an operation in another part of the company where they were using litres of Methanol in a washing process without wearing protective gear. Turns out that as little as 30cc of pure Methanol, either inhaled, ingested, or absorbed through the skin, will cause damage to the optic nerve. In the case of Methanol, the warnings are there for a reason. |
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| Author: | Mario [ Sun Jan 30, 2005 10:25 am ] |
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I can see how one can ingest 30 ml of methanol on purpose, but absorbed?(unless I hold my hands up as a cup and let you fill it, then stand there until it is all absorbed by my skin). We likely use less than 30 ml to french polish an entire guitar, so unles I do that wrapped in a bubble, I'm not going to inhale it. What would the concentration have to be for the air to contain 30 ml of anything, in, say, an 800 sq.ft. shop, enclosed? Keep in mind that this is a rather slow evaporating liquid, and that no shop is truly enclosed. This is what I meant by "the danger is in the dose". You've just proven it. We're not going to drink it, we're going to wear gloves anyhow, and in the end, I don't believe we'll have used 30ml in all, so the concentration of methanol in the air is minimal, at best. We do need to be careful of everything we come in contact with, but worrying about this is bordering on paranoia. |
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| Author: | PaulB [ Sun Jan 30, 2005 10:56 am ] |
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Mario, I think the danger is in having a cavalier attitude. Certainly if you're wearing gloves and have good ventilation, there's not a great hazard involved. Not wearing gloves and cleaning up with methanol, as in cleaning shellac off your hands with it, introduces a greater risk. Methanol being an organic solvent, is good at stripping away the natural oils in your skin that would normally protect you from aqueous solutions. You'd probably be surprised at how much you'd absorb through your skin - unfortunatly I don't have my old report with me or I could quote some numbers (I remember being surprised though). The bottom line is that you should wear appropriate personal protective equipment - and that means being aware of the risks associated with whatever chemical you're using. Ok, so I work in a chem lab and may be a little paranoid, but I've seen a few nasty accidents that could have been avoided, if only... |
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| Author: | Mario [ Sun Jan 30, 2005 11:51 am ] |
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I completely agree that a cavalier attitude is most dangerous, but what I'm taking here is a realistic view, not a cavalier one. We're not talking of spraying gallons of the stuff. French polish involves a damp(not wet) pad that gets rubbed onto the surface. We wear latex gloves in the process(at least I can't imagine anyone not wearing latex, or nitrile, gloves). That means the only danger left is from the evaporation, of which there is so little used, that the entire point is just about moot. |
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| Author: | PaulB [ Sun Jan 30, 2005 12:17 pm ] |
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Mario, It wasn't my intention to suggest that you have a cavalier attitude, though I can see how you might have got the impression - my appologies. I think where we differ, is that I can certainly imagine people not using gloves, hell, I've seen it often enough. Perhaps in your country people are a little better educated when it comes to protecting themselves from chemicals. Over here (downunder) that is not the case at all, and this is a global forum. Nuff said. |
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| Author: | tl507362 [ Sun Jan 30, 2005 1:08 pm ] |
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Sorry I brought it up! But in a way, I'm glad I did. So Mario, obviously you have tested both forms of alcohol and found that meth is better for a harder finish. When comparing the finish of one with ethanol or meth, if you rubbed the flat side of the fingernail across the the top with moderate pressure, would that still leave a mark on both surfaces? I want to be able to at least rub my nail of the surface and not have it mark. Thanks for all the insight into safety. I always wear rubber gloves when fp'g. I understand about the cautions of these chemicals. But I also noticed that using gloves helps when you accidently touch the surface while rubbing, it doesn't leave a mark. |
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| Author: | Roy O [ Sun Jan 30, 2005 4:48 pm ] |
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It's good to have another poster from the land of Oz. |
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| Author: | John Kinnaird [ Sun Jan 30, 2005 11:41 pm ] |
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I honestly do not see how the solvent can have much effect on the hardness of the final product in the case of shellac. Unless I am mistaken, the solvent completely evaporates leaving the shellac pretty much chemically as it was before dissolved. At this point it is in a film rather than a flake, but ethanol or methanol either way the solvent action is done and the alcohol is gone. I don't think the additional carbon grouping in ethanol will cause any difference in the way the shellac molecules reassemble themselves after drying. Just my opinion, no research to base this on. I teach science for a living and part of the job is running off ditto masters for kids. The ditto machine uses a methanol based solvent to transfer the ink to the page. OSHA has some strict guidelines for venting the ditto room based on research they did with methanol fumes and sick building syndrome. I'd be very careful about the cumulative effect of exposure to alcohol vapors. |
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| Author: | Michael Dale Payne [ Mon Jan 31, 2005 2:42 am ] |
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I kinda wanted to stay out of this one but I have to say that I agree with Mario that methanol produces a very hard finish. The fact that it gasses off quickly has a lot to due with it. It melts the shellac very well this allows the pad to transfer it and burn it in well with the shellac already laid down. As far as the methanol being a detriment by softening the existing film, that is exactly what is required to build an amalglamation. Methanol does have safety issues but so does shaving. Precautions need to be taken. I fell knowing and taking the proper precautions is just as much a part of the art of French Polishing as boding. It too must be done properly. The key to working with any hazardous material safely is knowing the hazard, knowing the precautions, and always observe them. |
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