Shellac - blocked

[mjmwallace]

I pulled out a package of shellac that I bought some time ago (at least 2 years). Some of the shellac flakes have formed a block. I tried crushing it with my hand and some of it broke off.

I recently read that when shellac blocks like this, it's no good. It won't dissolve in alcohol. However, I did a quick Google search and some people claim that the shellac is still usable.

Question, should I keep the shellac and hope it will dissolve ? And how do I keep shellac from blocking? I read that heat makes it block. Insulated container? And how long will flakes keep in this state?

Thanks

MJ

[RicodJour]

Straight from the horse's mouth...in this instance the horse being Jeff Jewitt.

"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=92t confuse natural wax with this). If you just purchased it, return it to the company you bought it from. Sometimes in summer months, shellac will cake together. This is known in the industry as "blocking" and is not a sign of bad shellac. Break up the shellac with a hammer and dissolve it in alcohol as usual. "

R

[mjmwallace]

I had read his remarks recently elsewhere, but I don't need the shellac now. I'd supposed I could do a quarter of what I have and see if will dissolve.

Reminder to self: only buy shellac when needed

MJ

[Larry Jaques]

Chill it and hit it with a spoon? Put the tiny pieces into the alcohol immediately. Warming the finishing jar of alcohol in hot water helps dissolve it, too. (I've had excellent luck with old shellac, but I don't use it on critical furniture, either. YMMV)

Keep it inside the house, where it's cooler.

-- Not merely an absence of noise, Real Silence begins when a reasonable being withdraws from the noise in order to find peace and order in his inner sanctuary. -- Peter Minard

[George W Frost]

I have had shellac block like this and I have heated the spirit in an old microwave outside, just a few seconds at a time till it was quite warm, then added the shellac, left it over night and it was quite usable from then. Of coarse, I don't have to say not to use a metal container to heat it, otherwise you won't have any spirit left, let alone the microwave.

[SonomaProducts.com]