Q: I want to fume the ridge beam in my house. Obviously, I can’t simply remove it, and place it in a tent for fuming. What would happen if I painted a light layer of ammonia on it?
A: First, fuming only works with woods high in tannin, so before you do anything, figure out what type of wood it is and whether it is one that is high in tannin or not. Second, fuming uses ammonia fumes, which is pure, concentrated ammonia. Once it is in liquid form it is ammonium hydroxide, which will color wood, but not in the same way as fuming. It tends to be less effective and yields a different color which is not surprising when you remember that you are no longer using pure ammonia, which is a gas, but rather a compound of ammonia and water. Even at best, fuming is a bit of a crap shoot. What color you get and how much impact the ammonia will have depends on the type of wood and, in this case, the concentration of ammonium hydroxide. For example, household cleaning ammonia is usually only about a 5% solution, and is a weak chemical stain at best. Ammonia from a blueprint machine is typically a 26% solution, and while more effective, is both dangerous and noisome to use. Finally, chemical stains, which is what ammonia is, only work on clean, raw, sanded wood. Call me a skeptic but I doubt that’s a good description of any ridge beam unless it is brand new and recently sanded. In short, I think it is a very bad idea for a wealth of reasons. Why not simply stain it the color you want it to be?
Michael Dresdner
straight talk about wood finishing
Leave a Reply