I was looking at some 6-8 year old silver proof sets on eBay and they are starting to yellow. I know from prior ownership of proof sets, yellowing is common. If I buy one with no yellow, I ask should I put a seal of super glue on the edges of the case, or remove & put in archival flips, or ??? Thanks in advance...
Hmm? I've got proof sets that go back to the 70's, and I've never had a problem with yellowing. Is it possible that the sets you mention were affected by environmental conditions? Edited to add: I also have silver proof sets that go back to the 90's.
Yep...I have hundreds of proof sets from the '30s to the 20-teens...no yellowing. By "yellowing" I assume you mean "toning".
I have Silver Proof sets from 1959-1964 and 1992-2020 and none of them have shown any toning (yet)! It depends on how they're stored. Mine are still in the original packages/holders and stored in non-PVC plastic boxes with dehumidifiers in each box. The dehumidifiers are changed on a regular basis. When I see how much toned coins are selling for, I get a "bright idea" to store them differently and let them tone. If I ever did that, with my luck, they'd tone black or some ugly unattractive combination of colors.
It's not only possible it's a certainty. Any and all coin toning is both directly and indirectly caused by the environment in which they are stored. And there are literally a thousand different variables.
The best way I know to protect coins from toning is to store them is something more reactive with environmental stresses than the coins themselves. I believe that's the concept behind Intercept Shield coin albums. I just wrap my coins in aluminum foil. It seems to work fine for me...and it's cheap (like me).
Last summer I sold some non silver sets from 1970's & 1980's with toning on some of the coins. Here is the set i am refeerring to.
Can you tell me a little more about the non-PVC boxes & dehumidifiers? Can you suggest a source online? thank you.
I'd exercise caution using an adhesive such as superglue since the vapors may inherently tone the coins if they are not already. As for the yellowing, I've noticed this predominantly on the 1999 business strikes and those in mint sets but have not noticed any in the proof version. not so much after 2000. Personally I like the golden tone.
Not sure what the holders are made of or how quickly the inserts will cause toning, but the silver proof sets are now .999 silver rather than .900, meaning they're much more reactive than before and will tone more quickly all else being the same.
No, absolutely not. A couple things, the gasses put off by super glue would be harmful to the coins. And sealing the edges wouldn't do any good anyway because the plastic itself is air permeable - air can and will go right through the plastic itself. That kind of depends on the specific sets and the mint packaging. The sets you posted in post #7, those are kind of doomed by the packaging because of the paper inside the packaging. That paper contains sulfur and the colored inks other harmful chemicals. And all that is right inside the outer plastic case - trapping everything inside it with the coins. What the mint calls "a beautifully designed package" - well, it's that "package" that's harmful to the coins. If one wishes to slow down toning then proper storage methods have to be applied. That means no paper, no cardboard, no anything except inert materials can be anywhere near the coins or kept in the same storage container, safe, SDB, or however wherever you keep your coins. And inside the container where you keep your coins you have to keep rechargeable silica gel packs to keep humidity as low as possible, and you must store them in an area where the temperature remains pretty much constant - cool and dry.
Toning isn't an "if" it's a "when" for a lot of people, myself included, I stopped fighting the war and accept it for what it is, the natural progression of metals given certain environmental factors. I'm in a place with high humidity, even indoors it's high, You can slow toning to a crawl, you can't stop it entirely. I'm not going above or beyond to try to stop it. Toning has won as far as I'm concerned, now lets see how it turns out.
Ahhhh, early stage sulfur toning. So if they were kept in there for 20 to 40 years it would go through the normal color toning stages? And were do you find rechargeable silica packs?
i dunno all about that. one way or the other it will balance itself out again, not clear if we will be here after that happens though. The cockroaches will be pleased though.
@Chris Winkler. I bought the plastic boxes from uline.com I don't recall which boxes I bought but you can call them and ask them which ones are PVC free. As far as the dehumidifier, any coin supply co. sells silica gel desiccant packs. I bought the 40 gram units that can be reused. Bought them from Coinsupplyexpress but they're sold by other coin supply outlets.