All i couldd find was threads telling you not to clean coins... I am looking for real methods that coin Conservation Services use.
I agree with Hobo, it is proprietary information that they are not going to release. You would have to apply for a job as a Conservator with NCS to get in on what they use or study metallurgy and conservation sciences / techniques to learn what is possible. Also the topic has recently been discussed so with more reading you can find more on how CT members have responded in the past, even recently this came up.
" Anyone here have any idea what NCS does to clean coins? I don't think anyone here knows for sure but some of you must have an educated guess? Acid and a wire brush?
I've already put a lot of thought into it. Here's my educated guesses: - Chemicals, they have a full lab stocked with everything you can imagine. I'm positive they do use the classic acid/thiourea reagents they make themselves at various concentrations. They also surely have a wide array of custom made reagents, each designed for a specific purpose. - Ovens - I suspect they do some heating as needed. They probably have the ability to purge and blanket the ovens with various gases or to run them under vacuum. Heat can be a powerful conservation tool if used properly. They may even have some tightly-controlled, pinpoint heat sources they use under magnification to vaporize various deposits. - Electrolyic cells - I think they may use electrolysis as needed with a highly controlled, customized apparatus and special eletrolytes developed in-house. - Gases - You can bubble various gases, such as hydrogen, around the coin that will react with and remove many surface deposits. They might have special fluids they use for this depending on the residue to be removed. The fluid could even be heated to specific temperature. The possible combinations of fluids, gases and temperature are endless. This could be a very powerful technique but it would require a lot of scientific thought and testing. If I figured it out, I'd keep it a huge secret too!
I agree; I think you have a very thoughtful list. It's certainly to their financial and industry-leading advantage to have all means available.
You think they may use a spectrometer to determine what foriegn substances is on the surface of a coin?
They might have an SEM EDXRF, but that analysis is time consuming and costly. I think they just have enough experience to determine the problem without resorting to instrumentation. I suspect an analytical determination is reserved for the very rare and valuable pieces.
Tools of the trade. I'm a Chef....the customer doesn't need to know or would care that I use a $2,000 Robo coupe to mince their onions.