Re: Mahogany door turned black

Douglas, Just for future reference and please don't take offense because no offense is intended, lye is good for opening clogged drains, but its use for striping wood should be restricted to things that you really don't care much about the quality of the resulting finish, texture, or color. Also, oxalic acid is a bleaching agent. The reason it has been used following a lye stripping is to restore the color to the wood that the lye has damaged. Lye will gray wood, giving it a weathered look. Oxalic acid will remove the discoloration just as it will remove iron staining on woods. Rinsing with water is the best neutralizer for lye, repeated rinising.

Now to help solve your problem. Can't really be sure why the wood turned black, there could be a couple of reasons, but it doesn't matter. My suggestion is to completely restrip the door with a methlyene chloride stripper. Try to set up in a shaded, open air area and don't worry about the rumor that mc is bad for you. If you are a rat living in California that ingests and breathes mc for 24 hours straight it is dangerous. After stripping and then rinsing with lacquer thinner let it dry for a couple of hours and look at the wood. You will probably have to use, or do, one of two things. Either mix the oxalic acid and wipe it over the entire door concentrating on the bad spots (this would be my preference) --or-- use the two part wood bleach kit (lye mixed with hydrogen peroxide in equal quanties). Keep in mind that the two part bleach can turn mahogany white if used in excess and it is possible, depending on the reason for your black spots, that it will not work on the trouble spots... Once you get an even color, go on with your staining and finishing. What stain did you use, what coating are you going to use, and is this an interior or exterior door?