The removal of Bronze disease.

[Chris Perkins]

I read your bronze disease note on the use of gloves and of course it interests me as a chemist. It's probably a mixture of the copper salts of acids produced by the breakdown of skin oil (sounds appetizing, eh?)

As such they are not water soluble, but I've found something that works all right.

Now I wouldn't advise this with an expensive coin, but if you'd like to stabilize a lesser quality coin, try the following:

1. Mix household ammonia one to one with distilled water

2. Submerge and swirl the coin until the barest tinge of blue appears in the liquid.

3. With gloves, remove the coin and stroke the spots with a cotton swab.

4. When finished, rinse well with distilled water and dry immediately with a clean cotton towel. Get the coin thoroughly dry.

The ammonia will bind any copper ions and the alkali should dissolve the acid parts. Ammonia can attack copper metal, so don't leave it too long.

[josie]

Thanks for the info.