I have a few coins with bronze disease, which I’ve been managing by periodic baking or sunning, and generally storing in a very dry, closed trunk with open containers of desiccant to keep them ultra-dry (plus the de-humidifier machine that runs 24/7 in the corner of the room, but that’s an expensive option for not too much return). So the BD hasn't really advanced much, even though I have moved from arid Arizona to humid Illinois. I’m considering testing Sodium Tetraborate, aka, Borax, to see if that works. I am hoping I may get some input here on that. My main concern is that my BD coins tend to actually be the better ones... or maybe I just notice it on better ones, since the worse ones pile up in boxes and bags of hundreds and up (I'm talking culls from bulk uncleaned lots here, and it's hard to find any clear BD cases--I guess it's the ones that get the most attention, having been soaked or treated with acidic solutions, that end up with the BD). Usually people talk about treating bronze disease with sodium bicarbonate (baking soda) + sodium carbonate (“washing soda”)—the latter I guess can be hard to find except online, and there it is expensive. Also there are the Gringott’s BD Killer type products—don’t know what the ingredients are in those. Another I’ve seen mentioned in more scholarly/expert publications (beyond my level of understanding) is Sodium Sesquicarbonate, which supposedly works very well without being overly destructive of patina—but this is even harder to find, except in chemical supply stores. All these things are alkaline/basic, like lye, which is important because acids reacting with the bronze, in the presence of moisture, are the culprits, as I understand it. Besides the commercial solutions, all those have similar uses: water softening, desiccants, detergents/soap bases (instead of lye), jewelry/metallurgy uses. (Someone mentioned something called biox in an older thread, and I couldn’t find any information about that...) One product that I’ve not heard mentioned is Borax (Sodium Tetraborate). This is widely available and cheap. It has the same household uses and similar alkalinity to S Carb and S Sesquicarb. My hunch—based on very minimal understanding of chemistry—is that Borax would work (i.e., dissolved in boiling water, á la baking +washing sodas method). They are salts of different acids: carbonic vs boric acids. I’m not sure what that means exactly, except that Borax isn’t as similar to sodium carbonate as sodium sesquicarbonate is (both widely purported remedies). Would anyone provide an opinion, based on experience or chemistry expertise, on whether S Tetraborate would work? I am considering trying it on some cull coins (which don’t happen to have BD) for practice, mainly to see what it does to different kinds of patina at different concentrations. Even if it turns out non-destructive, though, I’d feel better about stepping up to the few BD coins. Maybe I could “give” some of my culls BD by letting them sit in the bottom of the cat litter box for a month or so... :goofer:
You might want to try to find out if any chemical products at Home Depot are actually made of washing soda. For instance, the cheapest source of nitric acid is to buy a bottle of stump remover.
I am not recommending treating anything yourself, but sodium carbonate (“washing soda”) AKA soda ash is available at any pool supply store cheap. See http://www.lesliespool.com/browse/H...sh-50-lbs/D/30100/P/1:100:1000:100030/I/14738. In stead of playing with home made stuffs, why not use something made specifically for your problem? See VERDI-CARE™ ALL METAL CONSERVATION FLUID http://www.wizardcoinsupply.com/verdi-care.html
I think those are both good suggestions and worth trying out. One issue, though, is that a single product or chemical doesn't produce the same results on every coin (especially since I collect a range of Greek, Roman, and early-to-late Byzantine coins, the alloys and "fabric" vary tremendously and react in different ways; likewise different qualities of patina may require different solutions, in both senses of the word). I guess I also like the DIY aspect of knowing which solutions work for what (and the commercial solutions tend to keep their ingredients "propietary")--and as far as I can tell a single cure-all doesn't exist. And since my cull/practice coin pile is big enough, there's not much risk of damaging anything of value by testing something new. Again, I do think those are good ideas. Just looking for another tool to have in the belt when the situation calls for it. Don't know if Borax is that, but it seems plausible that it might be, and that someone would know either way.
I apologize for resurrecting this somewhat old thread, but I thought it was worth mentioning something I just realized: Soda ash is not only available at pool supply stores, but it’s also used as an activating agent for good quality tie-dying. If there is a good art supply store or fabric/hobby store near you, and they carry supplies for tie dying (the brand I’m familiar with is Jacquard Procion dyes), they might have the bags of soda ash. I bought some tie dying stuff on sale a few months ago, and didn’t realize until today that I was also buying a well-known bronze disease fighting ingredient. It’s probably more expensive to buy it this way than at a pool supply place, but it still wasn’t very expensive.
