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 Replies: 8 / Views: 1,000 |
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Valued Member
United States
143 Posts |
Hello everyone, hope it's a good day :) I've been running coins out of a basement to examine them in a partially heated room. I'd say the basement runs around 20 degrees, while the exterior area is 60-65 (Fahrenheit in all units). I've noticed a sheen, almost like an oil slick, has started appearing on more coins than I expected. They have been stored in different ways, but most of the effected are AU and above. Is this a temporary discoloration? Is this temperature related at all? I suppose I'm looking for answers about the effects of changing temperatures on metals. Happy to provide further information or pictures - I hate to be vague, but the problem and question seem general enough to try and pull some information from you folks before digging further into causes. Thanks in advance for your time and contemplation; on an unrelated note, after 50 posts, I still think this community is full of some great people. Glad to be aboard  |
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Pillar of the Community
 United States
7973 Posts |
My best guess is that something is condensing on the surface when you bring the cold coins into a warmer room.
This kind of temperature fluctuation should not affect the metal to the best of my knowledge.
Edited by tdziemia
02/12/2021 09:02 am
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Bedrock of the Community
United States
10284 Posts |
When my coin mail arrives, I leave the package unopened for a few hours in the cooler part of the house. There is a slower adjustment in temperature. This goes both ways, hot or cold outside.
I would suggest a gradual transition over time when moving them. Maybe some kind of cooler. Take the cooler downstairs and put the coins in and close it and bring it up and let it sit in a less warm area for awhile.
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Bedrock of the Community
United States
19301 Posts |
Would really love to see some photos of what you're encountering. Thanks.
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Moderator
 United States
190660 Posts |
Quote:
I'd say the basement runs around 20 degrees, while the exterior area is 60-65 Quote:
My best guess is that something is condensing on the surface when you bring the cold coins into a warmer room. If these temperatures are correct, an item will attract condensation when taken from long-term storage at 20°F into an area that is 65°F with a relative humidity greater than 18%. http://www.dpcalc.org/ |
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Pillar of the Community
United States
7973 Posts |
If you leave them in the 60-65 degree room for a day, what happens? DO they still have the sheen?
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Bedrock of the Community
United States
19301 Posts |
Hate to be a pest... Any chance we could see a few photos?
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Rest in Peace
United States
18456 Posts |
I would say the main culprit of the sheen and oil appearance is the humidity in the basement . You didn't mention how long the coins were in the basement . Most coins affected by temperature changes occur over at least a 3 year period where the coins are stored in a 4 season climate . I really doubt that you will see any difference's in days or weeks by bringing them from cooler to warmer temps .  |
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Bedrock of the Community
United States
20753 Posts |
You should get a Hygrometer to measure the Humidity too. And do you use any kind of oil lamps in your house? Kerosine Lamps too effect the air.
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Replies: 8 / Views: 1,000 |
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Posted 02/12/2021 10:06 am
