PDA

View Full Version : methenol & shellac



Dave Tinley
05-25-2005, 9:00 AM
Can Shellac flakes be disolved in Methenol/Wood Alcohol?
I know there are some dangers with wood alcohol, but does it dissolve the flakes like denatured alcohol??

Thanks

Dennis Peacock
05-26-2005, 1:21 AM
Good question Dave. I've only used Denatured Alcohol and Homestead Finishings "Bekhol" and both with very good success. One thing to note though, the Bekhol dries slower than standard D.A. so you can spray shellac with very good results since it flashes off slower that D.A. Hand applied shellac should be done with standard D.A. so that it will dry quickly for you...but, with Bekhol, you can keep a wet line longer than with D.A.

The best thing I can tell you is to try some methanol/wood alcohol with a few flakes and see how it does. Some "purests" of shellac perfer using "EverClear" since it is almost a Pure alcohol and they "say" it provide a better and harder finish with shellac than standard D.A. I don't know for sure about that, but...it sure would be expensive to buy a gallon of EverClear!! :eek: ;)

Doug Shepard
05-26-2005, 7:53 AM
I visit several luthier forums as I eventually plan on making a few instruments. I've seen this topic brought up more than once on those sites. Some of these guys won't use anything but methanol.

I checked the frets.com site (a great resource BTW), and here's what they have to say:

As a wood finish, we use shellac resin dissolved in alcohol (old timers called this liquid shellac "shellac varnish.") In fact, alcohol is the only solvent for shellac, and even then it takes quite a soak for the solid shellac to dissolve. Most alcohols will work, although the lower the boiling point the faster drying the shellac is and the better it works as a finish. Ethanol, methanol and denatured alcohol are the most commonly used, and in my experience, they all work equally well. Methanol dries fast, but is the most poisonous. Ethanol (booze) is difficult or expensive to get in high purity.

Denatured alcohol is really ethanol with a small amount of bad stuff in it so you can't drink it, and it works very well. It is important, though, to get a good grade of denatured alcohol. The cheap grades, often sold as "shellac thinner," have too much water or other impurities to be effective in a fine finishing product. Too much water will make the resulting shellac finish come out cloudy looking, and we don't want that!

If you're interested, the full shellac article is at http://www.frets.com/FRETSPages/Luthier/Data/Materials/Shellac/shellac.html (http://www.frets.com/FRETSPages/Luthier/Data/Materials/Shellac/shellac.html)

Tim Sproul
05-26-2005, 1:57 PM
I agree with Doug.

The best alcohol solvent for shellac is methanol. That doesn't included any concerns about application or safety.

Some things to think about - the faster drying a finish, the less it "self-levels." Methanol dries faster than ethanol. Erego, it is more difficult to get a nice smooth, flat finish with methanol than ethanol. I like to add propanol to dissolved shellac if I want the finish to be more self-leveling.

Exposure to methanol is toxic. A common problem being vision loss or impairment. And this occurs from breathing the vapors or drinking it. Wear a chemical respirator if you're dead set on using methanol.