Shellac gone off - How to tell?

[simon_b]

Hi
I bought some shellac flakes and mixed it with 100% meth a few months ago. Unfortunately, I have not used that much of it.

How will I know if it has gone off, or if it is still usable?

Can I mix it with more meth to get a sanding sealer that will last longer? If so, how much do I add?

Cheers
Simon

[watson]

G'day Simon,
Made up shellac has a use by date......but if diluted say 5 or 6 to 1 with ethanol it makes the best sanding sealer.
And another bag of flakes to replace your made up shellac is not going to break the bank either.
Do you have a copy of the Polisher's Handbook??
Its all explained in there in great detail.

[MacS]

Simon,

Test it on a piece of clean glass, and also a piece of clean dry wood, allow it to dry, check it for color and adhesion, it should stick fast. If not, do not use it, mix up a new batch.

Was the Shellac flakes dewaxed? If not did you decant the wax out of the shellac. You could use about 5 to 10% of the wax in the Shellac to make up a sanding sealer. Do not over- do it, as the wax will leave the sealer too soft. Be sure that you sand the sealer really good after it dries, as this also will leave the sealer too soft, the wax is basically added to only make the sanding sealer easier to sand not to bulk it up.

Do not use this sanding sealer for the finishing coats, mix up a new batch of only the shellac flakes.

Good Luck

MacS