My shellac is like jelly; what’s wrong?
Quickstep
| Posted in General Discussion on
I mixed up a batch of shellac from flakes and part of it seems to refuse to dissolve. I ground the super blond flakes into a fine powder using a coffee grinder, then added denatured alcohol to make about a 1-1/2 pound cut. I let it dissolve over a period of two days which has usually been long enough when I’ve ground the flakes. When I strained it, about 1/3 of it was like jelly. I poured the gelled stuff back into the jar and added some more alcohol. The shellac that went through the strainer seems fine, but I’m reluctant to use it because the rest didn’t dissolve properly. Anybody know what’s wrong? The alcohol is fresh and the flakes seemed fine.
Replies
Quickstep,
The super blond flakes I use, do the same thing; sometimes with even a higher percentage being reluctant to dissolve. I stir the shellac several times a day and the gel like mass will dissolve. After that it is perfectly usable.
Rob Millard
http://www.americanfederalperiod.com
http://www.rlmillard.typepad.com
Shellac gel
A chemist's perspective: I suspect that your flakes are not 100% dewaxed or otherwise purified. The waxes and other non-polar impurities are not soluble in alcohol, hence the gel.
You can get clean stuff (ex. Germany).
http://www.toolsforworkingwood.com/Merchant/merchant.mvc?Screen=PROD&Store_Code=toolshop&Product_Code
Please check your shellac. Shellac has an expire date, it will damaged and cannot be used after it stayed for a periode of time event it still in the flake form..
When it is in the liquid form it will damaged in shorter time
good luck
Jeff Jewitt has an article titled "Shellac - A Traditional Finish Still Yields Superb Results" on http://www.homesteadfinishingproducts.com under the link "Articles." It reads in part:
"Dry shellac flakes store indefinitely under proper conditions, but contrary to what you may hear, it won't store forever. Given enough time, especially under hot, wet conditions, dry shellac reacts with itself to form polymers that are insoluble in alcohol. Shellacs that have been dewaxed are more prone to this. You can extend the usable life of dry shellac flakes by storing them after purchase in a cool, dry area -- a refrigerator is best. A test for suspected old shellac is easy -- simply dissolve the flakes in alcohol. Most shellacs should be totally dissolved within three days. If you see a gelatinous mass after this time, the shellac is past its usable life and should be discarded (don't confuse natural wax with this). "
I had a jar of flakes several years old that had been kept tightly sealed in a small fridge, and it formed a gelatinous mass that wouldn't dissolve. I bought some new flakes and with the same DNA they dissolved in a couple hours.
You're dead right, Don. I got fresh flakes and I was amazed how quickcly they dissolved.
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