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The online literature stresses using high proof denatured alcohol. I'm using lesser proof from Home Depot.

What problems does this introduce?

Seems every resource I can find omits the "because if you don't use high proof...." part.
 

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May turn cloudy? Alcohol has an affinity to adsorb water. That`s the reason I`m guessing. I`ve used methyl alcohol that was 99 or 100 % and it seemed to work okay but it isn`t good for you to absorb it or breathe the fumes.
 

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I took a finishing class on shellac last saturday. The instructor said you want as little water as possible because water will slow down the drying process.
 

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Discussion Starter #5
I took a finishing class on shellac last saturday. The instructor said you want as little water as possible because water will slow down the drying process.
DA in a can contains water??
 

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Anhydrous alcohol is more expensive to produce so I believe most DA is made from distillation based alcohol. That would be about 5% (190 proof).
 

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I've looked into this before, the best I could come up with are:

A) the higher proof alcohols do a better job of dissolving the flakes.
The argument against this is that if you pulverize (really do a GOOD JOB of it) the flakes prior to mixing, no real
noticeable gains are made.

B) The higher proof alcohols evaporate quicker. Thus speeding up dry times.
Here the argument is that quicker dry times make some applications more difficult.

Because of the fast evaporation rate and supposedly better dilution there are those who prefer 190+ proof for French Polishing. Allowing for
a quicker building up of the finish.

The one thing I never did find was quantitative proof for the use of higher proofs one way or the other..
 
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Well, I'm still pretty much a beginner with shellac but did take an 8 hour course this weekend. Basically, the instructor held up a can of Klean-strip denatured alcohol from a big box store and said "this is as good as it gets".

By the way do not buy it from Rockler - they want $20 for a quart, same brand. Sheesh. I don't mind spending a little more to keep a specialty store like that in business but that's just insulting. My local lumber yard had a gallon for $20. HD sells a quart for like $7.
 

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I have used shellac for many years. I to have tried several different kinds of alcohol. A few years back there was a old boy who made grain alcohol which was 190 proof pure alcohol. I bought a gallon for $9 from him. Pretty potent.:grin: Hey had to try it. I did not find any difference between it or what I could buy from the lumber yard. I do like a higher proof like Bill said for a nice French polish. Works well.
 
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Got me curious. From Wikipedia: Denatured alcohol, also called methylated spirits, is ethanol that has additives to make it poisonous, extremely bad tasting, foul smelling or nauseating, to discourage recreational consumption. In some cases it is also dyed.

Because of the diversity of industrial uses for denatured alcohol, hundreds of additives and denaturing methods have been used. The main additive has traditionally been 10% methanol, giving rise to the term "methylated spirits". Other typical additives include isopropyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, and denatonium.

British standard formula: Completely denatured alcohol must be made in accordance with the following formulation: with every 90 parts by volume of alcohol mix 9.5 parts by volume of wood naphtha or a substitute and 0.5 parts by volume of crude pyridine, and to the resulting mixture add mineral naphtha (petroleum oil) in the proportion of 3.75 litres to every 1000 litres of the mixture and sometimes, synthetic organic dyestuff (methyl violet).

What is Methyl alcohol? Methanol is the simplest alcohol, and is a light, volatile, colorless, flammable liquid with a distinctive odor very similar to that of ethanol (drinking alcohol). However, unlike ethanol, methanol is highly toxic and unfit for consumption, and is used as an antifreeze, solvent, fuel, and as a denaturant for ethanol. It is also used for producing biodiesel.

Other interesting details, not necessarily about woodworking. Torpedo juice is American slang for an alcoholic beverage, first mixed in World War II, made from pineapple juice and the 180-proof grain alcohol fuel used in United States Navy torpedo motors before electric motor driven torpedos. Various poisonous additives were mixed into the fuel alcohol by Navy authorities to render the alcohol undrinkable, and various methods were employed by the U.S. sailors to separate the alcohol from the poison. Aside from the expected alcohol intoxication and subsequent hangover, the effects of drinking torpedo juice sometimes included mild or severe reactions. Methanol causes blindness when ingested, and cannot be made non-poisonous. Sailors tried to remove the poisonous portion by filtering it through a compressed loaf of bread, but that method was not completely effective.

Perhaps more than you wanted to know, but interesting to me.
 

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I'm no pro, but I've been making shellac from flakes for years....DA from a box store works fine from my experience. I've heard you can use Japan drier for speeding up drying time, but I've not tried it but may test it..it could come in handy at times. I've found that the quality of the flakes makes the biggest difference in finished product.
 

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I've never used Japan drier, but it's my understanding that it's not so much a "drier" as an accelerator of curing of oil finishes. Shellac relies entirely on the evaporation of the solvent (ethyl alcohol). The only way to quicken the drying time of shellac is to make the solvent more volatile than ethanol, such as adding something like methanol or acetone. With a really volatile solvent, though, you risk premature drying of the shellac, which could decrease the effectiveness of bonding with previously applied layers, and with spraying, risk drying before the shellac even hits the finish surface.

Japan drier is predominantly (80%) mineral spirits, which is much less volatile than ethanol, and probably not even miscible (mixable) with alcohol, and would actually increase drying time. Agree that plain old big box DA works just fine.
 

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Well, I'm still pretty much a beginner with shellac but did take an 8 hour course this weekend. Basically, the instructor held up a can of Klean-strip denatured alcohol from a big box store and said "this is as good as it gets".
I think he's right. If you pull up the MSDS it only lists two ingredients. A mix of ethyl alcohol and methanol. I've never mixed up shellac but I can't believe the Klean-strip wouldn't work just fine. It's all alcohol in a couple of different forms.

http://www.kleanstrip.com/uploads/documents/GSL26_SDS-1625.6.pdf
 

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I've never used Japan drier, but it's my understanding that it's not so much a "drier" as an accelerator of curing of oil finishes. Shellac relies entirely on the evaporation of the solvent (ethyl alcohol). The only way to quicken the drying time of shellac is to make the solvent more volatile than ethanol, such as adding something like methanol or acetone. With a really volatile solvent, though, you risk premature drying of the shellac, which could decrease the effectiveness of bonding with previously applied layers, and with spraying, risk drying before the shellac even hits the finish surface.

Japan drier is predominantly (80%) mineral spirits, which is much less volatile than ethanol, and probably not even miscible (mixable) with alcohol, and would actually increase drying time. Agree that plain old big box DA works just fine.


ou're probably right..iu've never used it either,but think I reads that somewhere...who knows..can't remember what I had for breakfast yesterday much less technical stuff from last year.... but I found that shellac flakes don't keep as long as I thought they would(maybe I was hoping for a LOOOOONG time at the cost of 'em).......
 

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Only a year according to what I've read Butch.
 

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Discussion Starter #16
From shellac.net:

How should I store the dry shellac flakes?
Kept in a cool, dry, dark place, the shelf life in my shop is 3+ years. Your mileage may vary. Never leave your shellac in a closed car. It will melt into a brick. Of course the good news is you can always smash the brick and then melt it down.
 

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From shellac.net:

How should I store the dry shellac flakes?
Kept in a cool, dry, dark place, the shelf life in my shop is 3+ years. Your mileage may vary. Never leave your shellac in a closed car. It will melt into a brick. Of course the good news is you can always smash the brick and then melt it down.
cheese grater???
 

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I've looked into this before, the best I could come up with are:

A) the higher proof alcohols do a better job of dissolving the flakes.
The argument against this is that if you pulverize (really do a GOOD JOB of it) the flakes prior to mixing, no real
noticeable gains are made.
I use a small coffee grinder to pulverize the flakes. I'm pretty sure someone on this forum suggested that to me years ago.

I've found that during the winter it takes twice as long to get the flakes to dissolve, even when I keep the jar near a heat register.
 
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