Oily Residue on UNC Australian Coins In Original RAM Plastic/Vinyl Wallets

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Joined: 26-Jul-2019
Posts: 9
Good afternoon, Since I’ve started cataloging my coins, I’ve come across an oily residue on some coins that have been kept in their original plastic/vinyl wallets from the Royal Australian Mint.

It appears as tiny dots similar to pitting on the coin, but can be wiped off. It also seems to be on the inside and outside (to a smaller degree) of the sleeves the coins are kept in (see images). I thought it was age related as the first two sets I found it in were my UNC Year sets from 1970 and 1971, however my 1982 UNC Comm Games $10 Silver Coin has the same.

While I just wiped the coins off with a tissue on the early sets, I’m more relunctant to do that on the $10 as it’s a nice looking coin. I’m sure it’s a well-known thing...I’m just new to the group and would appreciate some advice on what it is and how I deal with it. Thanks folks,
Joined: 22-Mar-2016
Posts: 1226
I believe your seeing "PVC" damage. In PVC plastic there is a plasticizer, which leaches out of the plastic and can damage coins. What you should do is soak the coins in acetone, and store them in non-PVC flips or 2x2s.
Joined: 4-Jan-2019
Posts: 45
looks more like moisture damage to me, however like person above has said it chemical/PVC damage (the water is causing the oils on the case to come off and leach on to the coin and reacting with the silver), and complete up to you what you want to do with the coins.
Joined: 22-Nov-2017
Posts: 782
Yes, most likely damage from the storage medium. As Steve said, you can soak it in something that won't damage the coin, acetone or alcohol, then rinse it and pat it dry with a cotton cloth. But most important is to get it into a decent non-plasticised flip.
What? Me Worry
oggy Numista team, Moderator
Joined: 8-Mar-2016
Posts: 1560
Those RAM kits are notorious for it. My 1963 needed a good long acetone bath.
Joined: 7-Feb-2011
Posts: 2265
I had the same problem with a couple of 70's & 80's Unc sets from the South African Mint - rubbing alcohol did the trick with them.
Just because you can't see it ... doesn't mean it isn't there - Anon

Catalogue referee for Celtic Britain, England, United Kingdom, New Zealand & Pre-Union South Africa
oggy Numista team, Moderator
Joined: 8-Mar-2016
Posts: 1560
Quote: "radrick007"​I had the same problem with a couple of 70's & 80's Unc sets from the South African Mint - rubbing alcohol did the trick with them.

I've never had that problem with the South African ones as they are usually nicely boxed, but the Indian ones (especially the 1969!!!) are another that have a real problem, as well as the 1927 and 1950's GB proof sets.
Joined: 30-Nov-2017
Posts: 120
When moisture gets trapped into these plastic wallets, there are high chances that they leave behind an oily residue after a period of time. Try changing the storage accessory once.. Check out lighthouse products here.. they are very reliable..
Joined: 26-Jul-2019
Posts: 9
Thank you all for taking the time to reply. I’ve finally purchased some Acetone and have my first lot soaking. I’m not sure how long to soak them though. I might leave them 24hrs. My Dad started me off on coin collecting many years ago (along with stamps, banknotes and even phonecards when they were popularz|) so unfortunately most of my albums have those ghastly PVC sheets.

What do do people use to store their non-valuable coins? Surely using the 2x2’s would be extremely expensive for the thousands and thousands of standard world coins of little value? I’m using 2x2’s for my crown-size collection and anything I value, but in the interim I am using these bags (pic below)
I don’t think they have the plasticiser in it so I’m hoping the coins will still be ok after several years.

Sarikanair, I looked at the link you suggested and almost choked when I saw the prices! Then I realised it couldn’t be AUD, surely (and if it is, I need to give up this hobbyB.). I did buy a lot of Lighthouse sheets a few years ago at a coin fair, but they were all for banknotes. They are definitely a good product, but not cheap.

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