[mistermac99]

Originally Posted by Spinnaker

Don't paint over enamel with lacquer. They are not compatible and can cause the paint to wrinkle or bubble. If you are dead set on a clear coat you might try clear Rustoleum enamel but test it on something else first to be sure the black and clear are compatible.

Maybe just putting the enamel in the letters and letting it dry will do. May not need a clear enamel. I think it's worth a shot. Going to be tedious work though.