Sealing with Shellac

Q:

I used waxy shellac by mistake to washcoat my mahogany tabletop. Can I still apply grain filler or do I need a coat of dewaxed shellac first?

Rick Wells, Marysville, MI

A:

You haven’t made a mistake. You should use a seal coat of shellac before filling the grain, and grain fillers work equally as well over both waxed and dewaxed shellac. Fillers typically have some color to them, and if you don’t use a seal coat, it will affect the color of the wood beneath. After the filler is dry, I put down another coat of shellac—use dewaxed—and then continue with the finishing process.