Q: I’d like to spray shellac for a finish, but I don’t have an explosion-proof spray booth. Can I do it outside? Ernie Ruxton, Twin Falls, ID A: You can spray shellac or any flammable finish outside, but pick a day with moderate temperature (55° to 75° F) and humidity (under 70%), and find a shaded spot with no direct sunlight. You should avoid strong winds, but some air movement—whether from a light breeze or a box fan—will prevent overspray from landing on the piece. Even if you do have a suitable environment for spraying, there are a few potential problems to guard against. When sprayed, shellac’s solvent, denatured alcohol, dries so quickly that it can prevent the shellac from “flowing out” correctly. It also can lead to a rough or grainy finish because the shellac partially dries by the time it hits the surface. Avoid both problems by using denatured alcohol with a low methanol content, such as Behlen Behkol. Check the label. You can identify low-methanol denatured alcohol by its lack of a “poison” warning. click to enlarge
You must be a member to access this story.
Become a member today and get instant access to all Fine Woodworking content!