Black Residue From Wet Red Oak

My guess is the tanin in the wood reacting with the metal.

Tannic acid (wet oak has it) and iron make for a black stain. Dry your tools off immediately to reduce the staining.

And Do Not Stand any Turned Item on anything Metalic

Apple wood reacts similarly. Try to avoid touching your wood with your hands when they have since they have touched your tool, toolrest, etc.

Derek

I've had the unfortunate results with Magnolia, Buckeye and Pacific Madrone too. It'll also happen if you get grinding dust on your hands and then touch the damp wood. For the wood's revenge, I also develop black stain on my hands from Black Walnut and Madrone -tip: a spritz of lemon juice will pretty well clear it up - may work on the wood too.

_____ American Association of Woodturners Cascade Woodturners Assoc., Portland, Oregon Northwest Woodturners, Tigard, Oregon _____

You've just re-invented oak gall ink (iron and tannin).

If it's a problem, oxalic acid bleach (Barkeeper's Friend) is good at shifting it.

-- Smert' spamionam

hmm so the ink works well? stays black?

Starts a little pale and darkens in a few days. Then it's enormously stable itself (thousand years at least), but it may cause damaging effects on the paper or parchment, unless you're careful.

i was thinking for the underside of mushrooms(wooden ones) because I carve in the little frilly bits. thanks for the link

Try ebonising solution. This is a recipe that's a few centuries old and works really well - especially on tannin-rich timber. It works on some other timbers too, so experiment and surprise yourself. The chemistry is very similar, but it uses tannin already in the wood.

Take a glass jar and some strong pickling vinegar. Punch nail-holes in the lid (it out-gasses a little, and you don't want it to burst !)

Throw in some iron. If you're in a rush, use the odd bits of wire wool left over from polishing. Old screws or anything work well too. Drop a heavy thing on top of this wire wool (a big piece of iron is ideal) so that all the iron is below the surface of the vinegar. Swirl it round a little to shake air bubbles out.

Leave it for a few days / week. It goes a dirty brown colour.

Apply to timber. 1/2 hour later you should see a good black, especially on oak, walnut or chestnut (and many softwoods too, which I don't understand).

Throw it away after 3 months, or if it starts developing a reddish-brown rust colour (usually caused by the iron being exposed to the air).

-- Smert' spamionam

in article snipped-for-privacy@4ax.com, Andy Dingley at snipped-for-privacy@codesmiths.com wrote on 1/7/04 5:26 AM:

thanks I'll try that, would it work on Yellow cedar?

I also read that if the wood dosn't have enough tanin for the reaction, wash it with strong tea. I guess it ups the tanin content in the wood. I have not tried either thing yet. Thought about ebonizing some poplar. Playing with segmented turnings.

Bruce

Doesn't work - tea has surface tension problems that stop it wetting the timber. Pomegranates work better (IMHE), and persimmons are reportedly a traditional stain in their own right (can I find usable persimmons in England ?)