I sanded a drop leaf table that I thought was solid mahogany, but it now appears it was veneered. The sander did not go through the veneer but appears to have gone deep enough in a few spots to leave a very light-colored area, yet the grain still looks like mahogany. It won’t take a stain, furniture touchup pen, and Minwax® PolyShades® won’t even darken it. I suspect it is glue that has seeped up into the bottom layer of veneer. Is there any way I can get this to take a stain, short of sanding off all the veneer and re-veneering it — something I have never done before? – Roger
Rob Johnstone: What I have for you is not good news. You have what we woodworkers call a “Really Big Mess.” Sorry. I would guess that your evaluation of the problem is correct — if you still see wood grain but the fibers won’t take stain, they are most likely saturated with glue. There is a way to solve the problem, but how effective it would be depends a bit on their size and how much work you want to do. You can put layers of color over the spots with a product called a glaze. It is like a very thin paint or thick stain. Michael Dresdner demonstrates how to use a glaze in our “Step-by-Step to a Perfect Finish” DVD. I mention that because it is a fairly subtle process. We have an online article that talks about it (click here).
In your case, you would need to treat each discoloration separately, feathering the color into the unaffected areas surrounding it. The glaze might muddy the grain pattern, as you are adding a layer of color over the top of the wood. If you get really into the process, you could even add some of the grain pattern back in with tiny strokes of an appropriately colored touchup pen. As you might guess, you can do this process well, or poorly. The good thing is, if you are not satisfied with how your coverup looks, as long as the glaze has not dried completely, you can wipe it off with its appropriate solvent.
There are at least two other options that I will mention. First is your idea of sanding down to the substrate and applying veneer. It is a good solution, but on a full-sized tabletop is no small job. You could also simply paint the top. I know that most of us woodworkers get a little sick to our stomachs when that is suggested — but it can look pretty. The next option would be to build a completely new wooden top for the table. Hope this helps!
Tim Inman: You have sanded down to the glue line of the veneer. I wish I could say that I had never done this, but guess how I know what your problem is? Rob’s first suggestion would probably be my first choice. If everything is tight, then I would try coloring in the flaw and go on. There is nothing like pressure to make a good student learn faster. Being able to do this sort of color work is invaluable to you as a finisher and accomplished woodworker. Second choice would be to put in a fill plug of veneer. Clever little router attachments are available that enable you to cut a perfectly matching plug patch and a hole to fit it. Rout out the damaged area using a template you can make from hardboard, then using the same template and switching the little router attachment around, rout out a plug of new veneer to fill it. This is also a good skill to have, “in case.” Re-veneering the entire top is always an option, but it seems to me a long way to go to correct a small problem. Better luck next time.