How do you know? Do you work there? Not one of their coins or medals has renwax on it and you know for sure?
Instead of arguing about how many teeth a horse has why doesn't someone contact the British Museum's numismatic department and ask them simply, "Do you use any of the micro-crystalline products, or anything else, to preserve the coins in your collection"? ?
I have no idea personally but I’d imagine they might wax the coins they display and maybe not for the ones they keep in the vaults?
A hoard of some 4000 Antoniniani of the late 3rd century was found in Switzerland (hoard of Ueken) last year. The coins were restored and - according to the press reports - treated with a "substance to preserve the surfaces". I don't know what that substance was. I imagine it could be a micro-crystalline wax. Anyway, it looks like professional restorators do use substances to preserve and protect the surface of ancient coins - at least in some instances.
Well, I'm going to take my own advice. I am going to try to contact the British Museum and ask them. I sent an e-mail to the museum and asked them about the use of micro-crystalline or any other kind of preservative on their numismatic items. I'll report what they tell me as soon as I get their response.
Well, I found the contact for the British Museum and sent an e-mail asking the questions and I got a response already. They will send the message to the appropriate department. Well, that's progress and maybe they will tell us much more about how they preserve coins than just about the micro-crystalline option. Stay tuned.
That would be useful to know. My guess is that they don't apply anything routinely. This does, however, not mean that a conservator wouldn't apply wax or some other material in certain cases. In the case of the Swiss coin hoard the 4000 antoniniani were cleaned using scalpels, maybe this process called for the application of some kind of sealant. https://www.ag.ch/de/bks/kultur/arc.../funde_fundgeschichten/detailseiten_64450.jsp If I look at bronze coins in major auctions, I often wonder if some kind of oil or wax has already been applied, perhaps to improve the eye-appeal in the catalog. I may be completely wrong, but look for example at this group of sesterti in the upcoming CNG sale: https://auctions.cngcoins.com/auctions/4-8YHV9/electronic-auction-460?categories=4-8YJO9&limit=48
I'm not sure this will conclusively settle things as British Museum employees are probably instructed not to say anything to the public that could be misconstrued as a product endorsement. It's also highly unlikely that they would wax all of their coins. I wax mine only on a case by case basis. If I had state-of-the-art humidity controlled storerooms like the British Museum or the Met i would not worry so much about some of my coins. That's for sure!
I asked the British Museum this very question a couple of years ago. This was the reply from a senior conservator in the Ceramics, Glass and Metals Section of the Conservation Department: We no longer use Renaissance Wax on our metal antiquities as its presumed protective properties have been superseded by other materials, notably the range of Paraloid© acrylics. Also, some scientific investigations recommended to stop using it due to its particular ageing problems. It becomes hard to remove due to molecular crosslinking and there is the possibility that it may break down into acidic by products. All soft waxes can pick up dust and lint and sometimes there are problems from heat (e.g. from photographic lights or display lighting) where the wax melts slightly and adheres to or stains showcase linings. If the coins have any chemical problems, such as chlorides or ammonia/nitrate compounds from soil environments, a layer of wax will seal these in, allowing them to “stew in their own juice” until the problems becomes visible as crystals force their way out of the coin surface through the wax. Hope this helps.
Educate me. On what type of coins would you use wax? Would you use it on gold, silver, copper, bronze coins? Would this be used on ancient, medieval and/or modern (post 1500 A.D.)? How is this applied? Are there before and after pictures? Can anyone apply this "wax" after practicing on cheap common coins or is this best left to the experts? Thank you in advance for any advice. PS Where does one obtain said "wax"? PSS Are there educational videos one can watch to learn about this process?
No expertise necessary. I just dip my fingers in, "massage" a bit into my late Roman bronze coin, and buff with a Dremel, but that's not necessary. Again, I don't really use it anymore. Here's a promo. Take the ad rhetoric with a grain of salt. https://www.shellac.net/RenWax.html
I rub with a cloth. I use it on bronze coins only. Not all of them but most. "a little dab will do ya"
Sounds like good questions for a Google search. My thought is primarily for copper/bronze coins with a rough, uneven surface and signs of porosity.
Back on Dec 26 2019 there was a thread on this topic under the name micro-crystalline. Some of your questions, including b efore and after images were posted.