Does Mahogany Contain Tannin ?

[Doug Shepard]

After handplaning some Mahogany over the last couple of days, I notice when I'm done that my hands are stained purple. I know the purple stain you get when working red oak is caused by tannin, but I didn't think Mahogany contained tannin ??? Just curious.

[Steve Wargo]

Yes, it does.

[Doug Shepard]

Yes, it does.

Thanks. Ya learn somethin new every day (at least here).:)

[Dave Anderson NH]

The other folks answered you correctly. The oils and salts in the sweat in my hands cause most woods to turn my hands a blue-black after I've been working for a while. Oak, mahogany, most of the exotics, black walnut, and a host of other woods cause this problem. My solution is pretty simple. I keep a large bottle of REAL LEMON in the regridgerator in the kitchen. After working I wash my hands with a pumice cleaner and then a regular hand soap. The final and most important step is to pour about 3 cap fulls of the Real Lemon into one palm and then wash the hands briskly for about 1 minute. The tannin stains fade almost immediately.

Warning: If you have cut or nicked your hands while working, it's gonna sting a bit.

[Steve Wargo]

Sorry, but I only had a minute to answer the other day. One of the ways I determine if a wood contains any tanic acid is to see if an "old" way of finishing included PDC (potassium dichormate). If it used to be finished with PDC then it most assuredly has tannins, as the result of the finish is from the chemical reaction between the tanic acid and the PDC. This is a great finish for mahogany, but is fairly nasty stuff to work with. I'm always affraid I'll mistake a jar of it for some Orange Crush soda and wake up in the emergency room. Hope this helps and sorry for the ramble.