Is Acetone really the trick?

Log in or Sign up to hide this ad.

I've been seeing something similar using my mixture of acetone and alcohol or even pure alcohol.

Rinsing immediately in warm water seems to lessen the effect.

I'm going to try rinsing while still soaking next. I'll just change the alcohol to warm water as quickly as possible giving the air no chance to get to it.

 

You can only imagine my condition.

The mint set packaging is four layers with a soft PVC laden plastic touching the coin on both sides. These inner layers apparently serve as a sort of "glue" to hold the mylar together when it is crimped.

I have no excuse. I've known this for years and done very little about it. Even coins stored in my safety deposit boxes are ruined.

 

Proof sets have proven relatively stable so far. Pennies are often ruined but other coins for the main part are OK. They may or may not prove suitable for longer term storage but so far all the ones in hard plastic are "good enough". The SMS are a little worse but the coins mostly just haze and this can usually be corrected. Older sets in soft plastic are hit and miss and should probably be removed or put into ideal storage conditions.

The mint took vary little concern for purchasers. In their defense they might not have known how bad the mint set packaging was. They did finally tweak the packaging in '81 and then switch to something more stable in '84 with even better in '85. '85 and later sets are rarely affected but they probably still aren't suitable for long term storage. Young people should be reminded that the "long term" comes much faster than their expectations and much more slowly than their plans.

I'm heartsick about the coins I've lost. I thought saving coins for the future would be a laudable goal and then I allowed them to be ruined.

 

I should add that it's not as simple as just keeping them wet and there must be something left on the coin when this happens.

 

I just came across a beer bottle of cents that I filled and taped off in 1982. It's a brown bottle, so it's hard to get a true reading on the color of the coins, but it looks like the ones that were lustrous when I put them in still are.

I used packing tape, which probably ruined any coins it actually touches, but seems to have kept oxygen out pretty well.

Don't know how they would fare over centuries, but after 35 years, so far, so good.

 

Don't ever do this to any coins you think might have numismatic value. eZest is a coin dip that could be used for jewelry (I guess), but is pretty specifically for coins, and be careful with it also.

 

...yes, don't use just any jewelry cleaner on coins.

 

Where did you get that idea?

 

Pretty good "cleaning" strategies exist for silver and gold coins. Nickel and CuNi coins are more problematic and aluminum is a REAL problem to do anything with.

 

Every once in a while you'll see them delaminate.

 

I don't think it's something left on the coin. My theory has been that it has to do with rapid oxidation. The coin is coming out of a cold bath and is drying rapidly causing a difference in temperature between the surface of the coin and the ambient air.

 

Doug, we're talking about Aluminum coins having been rinsed in acetone here, not silver. No amount of rinsing is going to fix the spots left behind on an aluminum coin. We're trying to figure out how and why aluminum is affected so adversely by acetone.

 

I searched every acetone-aluminum article I could find and coin forums ( 7 people total said it happened to them or a friend , but no one had any photos that showed the effect of acetone damage. Several claimed acetone did bad things to their wheels, castings, cars, bikes, etc. but no info on the aluminum alloy content. Many others said it hadn't happened to them, but with the small aluminum coins, collectors generally have available, one can not draw any secure conclusions. If anyone has such photographs I would very much like to see them. I know another collector who purchases pound bags and searches for rarities since the bank banned him from boxes of coins and I will ask him to look for some with all stages of wear to try it on them sometime. My suspicion is that the observers who claim it happened remember wrongly about the surface before acetone use.

Jim

 

Honestly can't figure out what acetone would do to an Al coin.

 

It will take me a little while, but I am going to buy a few cheap aluminum coins, acetone treat them, and take copious before and after pictures. I'll send the disfigured husks to you or any other interested numismatic chemist for whatever surface samples you desire.

I assure you, I do not misremember the lustrous surface before and hazy, spotted surface after.

 

You certainly have talked into trying it.

 

Anyone willing to participate in my experiment will receive credit in the thread I'll start.

Please see my wanted poster here: https://www.cointalk.com/threads/wanted-aluminum-coins.322597/

 

[Raises hand in embarrassment]