Shellac flakes not dissolving much

[Jim Tarjan]

It's been about three weeks since I mixed them, and the alcohol/shellac flake mixture looks a nice amber color, but I can see flake remnants in it and when I pour it through cheesecloth a whole lot of solid shellac is left in the cheesecloth.

I'm using amber "Dewaxed Premium German Shellac Flakes" from Tools for Working Wood, and Behlen Behkol denatured alcohol. Actually I ran out of Behkol in the second batch and topped it off with some Ace denatured alcohol. One batch is one pound cut, the other one and a half pound cut. The flakes have not dissolved well in either.

I used this same can of flakes and Behkol on a previous project, which went great. The flakes almost entirely dissolved within a couple days, no sweat. But that was about a year ago.

The flakes have been stored in the screw-down plastic jar they came in , inside a sealed zip-lock plastic bag. They look fine, exactly like at first, dry and crispy.

I just tried putting the mix in a warm water bath because one book recommended it. I see no difference, no additional dissolving.

Old alcohol? Old flakes? Just strain it, and go ahead on it?

Jim

[Scott Holmes]

I'd guess old DNA or DNA that has had the chance to absorb alot of water.

[Howard Acheson]

Did you periodically agitate the jar? Sometimes, it helps to grind up the flakes into smaller pieces. Shellac should dissolve within 6-12 hours at a reasonable temperature.

[Kent A Bathurst]

Howie's dead on target - crunch up the flakes into smaller peices, and agitate/stir mixture. If I just let it sit, I always get a gooey clump on the bottom of the jar, and not sure that it will dissolve on its own.

From where you are today - try just stirring it every 5 - 10 minutes and see if it improves. If not, IMO strain it and go ahead, but try it out on a sample board - lay it on pretty heavy and check to see how/if it hardens. From JeFf Jewitt: "Shellac that is past its shelf life does one of two things: "It either won't dry hard, or will cause another finishing material applied over it to wrinkle.........dry flakes or buttons can be safely stored in a cool, dry place indefinitely...."

I use similar product from Homestead (Dewaxed German). FWIW - I use DA from Ace Hardware - never a problem of any kind. I keep my flakes double-bagged in ziplocks, and in the freezer (its downstairs near the shop - fridge is upstars - they've never been added to a dinner receipe, but they have made it as far as the kitchen twice ).

To be safe, you could mix up another batch, crushing the flakes and agitating every 5 - 10 minutes ( Some people have a cheap yard-sale blender they use for exactly this purpose - they basically make shellac flake dust - dissolves much faster). Usually takes me couple hours (I mix in a qt mason jar, and shake the jar every so often - just take the jar with me wherever I go, with a tongue depressor + paper towel in my pocket as backup - around the shop, wherever.... The neighbors are used to me showing up shaking a jar for cocktail hour on their deck). There is sometimes a small bit that gets strained out, but never a "whole lot". If this does not show an improvment, then I'd have to guess the flakes you got had a problem - but that would be out of character for a product from TFWW, I would think. Who knows - the flakes could have been compromised before they got to TFWW.

[Jerry Olexa]

As said above, its important to crush the flakes into smaller pieces before and agitate occassionally while its dissolving. Normally 2-3 days max.. You might need new DA..

[Jim Tarjan]

I agitated the flakes around plenty, with a wooden chopstick, starting on the first day. (Of course, that does involve opening the lid...) I'm betting on the denatured alcohol, during the months of storage, having absorbed enough water to impede the process. I stored it, along with the other flammable things, away from the house in a shed. (I store the shellac flakes in the workroom.) In that typical metal container they sell it in, with a screw-down metal top. Perhaps, over a period of months, once the top has been taken off and on a few times, and the container is half empty, some moisture from the atmosphere can leak through that hokey metal cap. Perhaps not enough to affect most common uses for denatured alcohol, but I gather dissolving shellac needs a very high alcohol percentage.

I should know soon, as soon as I can get to the Ace Hardware down the hill, buy fresh denatured alcohol, and mix up another batch. I'll break up the shellac as suggested, though it worked fine for me previously using whole flakes.

I've got a Fine Woodworking article by Donald Williams where he makes a pitch for high-grade denatured alcohol. But even Behkol is a long drive for me, to the closest Woodcraft. And it seems a bit much to order something like denatured alcohol mail order. Thanks Kent for the Ace Hardware thumbs up -- ten minutes away.

Thanks for all the input,

Jim

[Jerry Olexa]

Regular DA from your local hardware store has always worked fine for me.
g'luck....

[glenn bradley]

Maybe??? http://www.amazon.com/Toastmaster-11...913231&sr=1-18

[Kent A Bathurst]

......I've got a Fine Woodworking article by Donald Williams where he makes a pitch for high-grade denatured alcohol.

Yeah - you've prolly got moisture in the DA - I store my finishing stuff inside the shop - but then, a galllon of DA ain't around here very long.

I'm sure the FWW article has merit. I'm also sure there must be some incremental merit at the very fine margins for the people that use grain alchohol. I've never had a problem with the hdwre variety - but again, it isn't here very long - couple months at most, and its inside, and I rarely open the can - just to mix shellac, or refill a plastic squeeze bottle.

[Tony Shea]

Crushing up the flakes IS NOT necessary. It helps if you're in a bind and need shellac asap. But larger flakes should absolutely disolve over night at the absolute most of 24hrs, more like 12. I never break my flakes up as I always plan a day or two in advance and sure enough every morning my shellac is completely disolved. I also get my flakes from TFWW and have never had problems with them. I would agree that it could be your DNA. Sucks to waste a batch of flakes though as the stuff can get pricey. I've heard the quality alcohol argument as well but have never been willing to spend the extra $ for it. I've had good results with cheap Kleen Strip brand. Good luck and store the DNA a little better.

[Kent A Bathurst]

..........I always plan a day or two in advance..........

Hat's off to you

I'm more like "Awwww......C**P!!! NOT AGAIN!!!

[Ben Hatcher]

I put 1/2" nut in my shellac to aggitate the mixture without taking off the lid. It works very well. I've found plastic peanut butter jars work best since you can shake them like a spray paint can. Round glass jars works too but, obviously, you have to be a bit gentler.

[Chris Padilla]

If the shellac flakes are old...they may not ever dissolve completely. I'd suspect the shellac before the DA....

[Scott Holmes]

Stored (cool & dry) shellac flakes should not go bad... shelf life is indefinite.

I keep mine in the shop refrigerator.

Try fresh alcohol first.

[Jim Tarjan]

I bought fresh denatured alcohol and mixed up two more small batches. I broke up the flakes some with my fingers before adding the alcohol. It's three days later, with the same result: the pieces of shellac are still in there, a lot of it. It's not the gummy mass in the bottom thing, they are all individual and slosh around fine. They simply won't dissolve, or only partly. Some of it dissolved, because the liquid is shellac colored, but there's a whole lot of undissolved floating around.

The moral to the story, at least the moral I draw, is that even unbleached shellac flakes don't last forever. All the articles warn about bleached shellac, that it deteriorates quickly, even dry. But dry unbleached is supposed to last "indefinitely".

These dewaxed (but not bleached) amber flakes worked perfectly on my previous project. When was that, at least a year ago. But when did I buy them, at least some months before that. It could have been close to two years ago that I bought them, and of course one doesn't know how long they've sat at the vendor. Incidentally, as far as I can tell, they look exactly the same as when I bought them, there is no visible deterioration.

I'm a sporadic hobby workworker (obviously). I sit at work, dream, and buy things for hypothetical projects... . For the pros, I would think a one or two year shelf life is as good as forever.

Donald Williams' Fine Woodworking article has just a bit of info on how they dewax the stuff. He says the industrial dewaxing involves solvent extraction, dissolving the shellac in methanol and then reconstituting into flakes. I'm not the chemist, but it would hardly be surprising if this procedure made the product more prone to long term decay. Any educated input out there?

If one does want to store them forever, perhaps extra measures are called for. Kent mentions freezing them. Or how about in a tight jar, with that heavy inert gas sprayed in, as with a half empty can of liquid finish?

I'm skeptical of grinding them up into powder. One runs the danger of disguising rather than eliminating the problem, seems to me.

For my part, I'm over it, I've still got my job and my dreams, and I'm churning the economy, ordering new ... buttons this time, just to try.

Jim