Q. Rumor has it that Armor All", the stuff people use for cars, can help purpleheart keeps its color. Is that true?

A. (Michael Dresdner) "Yes, in theory, and partly. Armor All" contains a UV absorber, which mitigates one of the avenues (UV degradation) that affects purpleheart's color. However, it is in a fugitive base (the media the UV absorber is in erodes off) and is therefore meant to be reapplied every few months. If you do that, you will have a good buildup of silicone oil on the wood. If you don't, once the base goes, so goes the UV protection. It also does little to protect against the other avenue of color degrade, oxidation, since it is not a film forming (read: drying oil) material. At best, it is one of the worst ways to go about it. The best is to use an exterior finish that contains UV blockers and absorbers. You can find many at marine supply stores, some paint stores, and through several smaller companies online, such as Swing Paints out of Canada. One online source, www.homesteadfinishing.com , even sells UV absorbers that you can add to water-based topcoats."