[Charlie P]

Hi, I am new to this forum. I have many years experience with paints and finishes.
I have encountered a problem with shellac blistering when exposed to direct sunlight on a hot day. I have done some test pieces on kild dried redwood to rule out moisture in the wood. I make art furniture (small tables with paited designs) and have only recently started using shellac due to allergies to other finishes. It works well for me except for this problem. The shellac had been dry over a week and had several coats. Does anyone know what could cause this?

 

[Mitch Cholewinski]

Charlie If the article was dry for a week what was it doing out in the hot sun? The sun will blister it every time if you have a heavy coat on it. A light coat of shellac will dry in 15 minutes and be ready to sand and apply another coat. So why is it out in the sun to blister? Sun, or heat from a wood stove and any water on shellac is fatal to shellac of any kind. Thin your shellac with alcoholl and put on lightly and it will be dry before you can clean the brush. I use shellac as a sealer on all my turnings. good luck Mitch

 

[Charlie P]

Thanks, Mitch. It was in my truck under a camper shell being delivered to a buyer with sun coming in the window. IS tis blistering unique to shellac or will other clear finishes do tis also? Its the first time I've had it happen.