Alleviate Sticky Shellac
Issue: Issue 183
Posted Date: 10/9/2007
Q: After a few days of drying, my shellac still has a tacky feel to it. What causes shellac to remain sticky and is there something I can do to alleviate this problem?
Premixed shellac has a definite shelf life, in most cases. Evidence of old shellac is its refusal to dry properly. Remove the old shellac and reapply, using fresh product. There is a shellac by the name of Zinsser SealCoat
which has quite a long shelf life, and is readily available.
Wash it off with denatured alcohol and start over with fresh shellac. Shellac breaks down over time by a process called esterification during which the shellac resin converts to shellac esters. The more esters in the mix, the slower it dries and the softer the final finish.