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Ted Mooney, P.E. RET
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What type of wood finish reacts chemically with gold and silver
Q. What type of wood finish reacts chemically with gold and silver? I have a hand-made earring stand and cannot use it for my earrings. It's beautiful and I'd really love to use it. Thanks.
Marianne Green- Durham, North Carolina USA
August 12, 2017
A. Hi, Marianne,
I'm doing some wood finishing myself, and I honestly can't figure out what sort of finish would react to any of the alloys used in gold and silver jewelry. I also did some searching online, because your question got *me* wondering about the finishes I've chosen to use, too!
Here is the Summary:
If your stand is reacting with any metals, I'd say that there is a 99.90% probability that it has not been given any finish at all. You need to ask the person who made it whether it has or has not been given a finish, and of so, with what.
Here is the Long Verbose Detail part:
As far as I was able to find over the past hour or so, my initial thought was correct:
metal reacts with *raw, unfinished* wood, but any decent wood finishes would be non-reactive.
Are you sure that your stand *does* have a finish on it? I ask because most wood *can* be polished to a decent luster on its own, and the tighter the grain, the higher the polish - for example, I know from experience that Gabon Ebony can be polished to the point where it gets to be astonishingly reflective.
If your item is finished with a coating of shellac or "lacquer" (which, as far as I've seen, usually seems to refer to nitrocellulose), especially if it's only a thin layer, neither of them is particularly resistant to humidity/wetness, so it might be possible that the stand could develop areas where the wood becomes exposed, and then reacts with various metal alloys in the jewelry. My impression is that wax can also wear off and expose raw wood, which is why it's not considered to be a finish at all. However, neither shellac nor lacquer themselves, and certainly not wax, can cause corrosion of metal and, in fact, many metals are actually coated with shellac or lacquer. (I don't include Asian lacquer that's based on Urushiol because, even though it's durable, as is evidenced by some of the astonishingly-old lacquered items that are still around and still look great, it *is* the same stuff that causes people to get those nasty hives from Poison Ivy, Poison Oak, and I think Poison Sumac as well, so very few people use it).
If the wood has been rubbed with either good-quality Boiled Linseed Oil, or tung oil
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, I'm not absolutely certain that the resulting surface would be completely non-reactive, or prevent any absorbed moisture from contacting the metal; on the other hand, however, both have stood the proverbial Test Of Time as wood finishes, and if there was any problem with reactivity, I doubt that they'd have been used for so many decades, even centuries, and by so many wood artisans.
If the wood is top-coated, however, with either 'natural' varnish (such as, amber and mastic heat-dissolved into walnut oil), or a manufactured polymer varnish (such as polyurethane or epoxy), neither should contain anything that would react with metals, and both would be tough - after all, the varnish used by Stradivarius on his violins and other string instruments was of course 'natural', and it's been pretty durable all in all! =;-)
So, again, If you're concerned, check with the artisan to be sure whether the stand *has* been given a finish, and if so, what it is and how many coats.
I hope that helps!
- Kris K.
- Richmond, Texas USA
This helps quite a lot. Thank you so much. Marianne
Marianne Green [returning]- Durham, North Carolina USA
August 14, 2017
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