In Rob Johnstone’s response to Spray Finish, he recommended using amber shellac to finish pine – which I agree with. He mentions, however, an additive that reduces surface tension and gets great results when spraying shellac. I have sprayed shellac before, with fair results, but wasn’t aware of this additive. So what is it?
Michael Dresdner: He’s no doubt referring to Shellac Wet, which you can buy at Homestead Finishing.
Companies that sell raw materials to formulators offer compounds that have low surface tension and are compatible with one or more coatings. Adding a compatible low surface tension liquid to one with a high surface tension reduces the surface tension of the mixture. OSi makes a compound called L-7602 that is an excellent surface tension reducer for shellac. Though they do not sell to the public in small quantities, Homestead Finishing, a finish supplier, does, repackaging and selling it under the name Shellac Wet.
Rob Johnstone: Ditto.