Do shellac flakes go bad?

[Larry Heflin]

I have some Hock blonde shellac flakes that have been sitting around for a couple of years that I decided to use. They had solidified into a big chunk. I beat them with a hammer and reground them with an old coffee grinder. I mixed some up for a 1# cut and have had them sitting overnight in a jar with DNA, which I shake everytime I walk by. They don't seem to be dissolving very well. Can they go bad? Suggestions?

Thanks,

Larry

[Jeff Jewitt]

Yes - dry shellac flakes go bad due to age/heat/humidity. While blocking (where the shellac flakes fuse together) may not be a problem, if they have been blocked for awhile they are no good. Failure to dissolve is the indication. Pitch 'em.

The dewaxed grades are the most prone to this problem, the worse ones being the dewaxed light grades. When you buy any dewaxed shellac flakes, I would recommend keeping them in a refrigerator until you want to dissolve them.

[Larry Heflin]

Thanks Jeff. In the garbage they go.

[Dave Gaul]

Also, if you didn't already know, you should only mix enough for what you need at the time, as the mix can go bad as well... pre-mixed shellac like Zinser's will last longer in the can, but mixed from flakes will spoil quicker...