My wife and I found some old wood doors stored in the basement of our Victorian home and want to reuse them. They look and have the weight of oak with what I’m guessing is a shellac finish. Should we use a chemical stripper or sand off the old finish? Should I refinish it with shellac or modern polyurethane?
Michael Dresdner: Definitely, strip the finish chemically. Sanding off finish is a recipe for problems, since you are likely to both leave finish in the wood’s pores, and damage delicate areas of the wood, such as edges and moldings. If the finish is actually shellac, it will come off easily with a 50/50 mixture of alcohol and lacquer thinner. Once the wood is cleared of all finish, sand the surface lightly.
When you are ready to apply finish, use Zinsser SealCoat as the first coat. This will lock in any contamination from waxes, oils, grease and polish that may be in the wood. After that, it is your choice. Shellac is more traditional, but polyurethane is more durable, so if the doors are to get a lot of hard wear, choose polyurethane. Either will go over the SealCoat without any problems.