Coin Community Family of Web Sites Join Thousands of Coin, Bullion, & Money Collectors
Royal Canadian Mint products, Canadian, Polish, American, and world coins and banknotes. Vancouvers #1 Coin and Paper Money Dealer Royal Estate Auctions - $1 Coin AuctionsCoin, Banknote and Medal Collectors's Online Mall 300,000 items to help build your collection! Join Thousands of Coin, Bullion, & Money Collectors Specializing in Modern Numismatics








Username:
Password:
Save Password
Forgot your Password?


This page may contain links that result in small commissions to keep this free site up and running.

Welcome Guest! Registering and/or logging in will remove the anchor (bottom) ads. It's Free!

Coin Cleaning Problem - Red Gunk

To participate in the forum you must log in or register.
Author Previous TopicReplies: 3 / Views: 1,231Next Topic  
Pillar of the Community
Ben's Avatar
United Kingdom
4208 Posts
 Posted 05/30/2014  09:16 am Show Profile   Bookmark this topic Add Ben to your friends list Get a Link to this Message Number of Subscribers
I dont know if anyones come across mention of this in the literature, but I went into my coin pot today and found a load of red gunk, covering my Allectus and spread to several other coins, but basically localised.

Its been coming off easily enough, but I'm sure its bacterial, so I'm going to change the water and boil the coins, flame sterilise all my instruments and quarantine anything from the pot (which includes the allectus and 2 nice Carausii).

What do we think this is? The Allectus is from long enough ago that its also had an extended period in Oil - could this be the food source that the bacteria are latching to, remaining on the coin? Is the gunk organic? It could be iron oxide being leached from the coin, I guess.
Pillar of the Community
pishpash's Avatar
United Kingdom
3626 Posts
 Posted 05/30/2014  10:09 am  Show Profile   Bookmark this reply Add pishpash to your friends list Get a Link to this Reply
No idea Ben, but keep us posted. Did you take photos?
Pillar of the Community
Ben's Avatar
United Kingdom
4208 Posts
 Posted 05/30/2014  10:20 am  Show Profile   Bookmark this reply Add Ben to your friends list Get a Link to this Reply
To observe the stuff, I didnt do anything harsh to the Allectus to remove it, just remmoved the excess. if its biological, it should continue to grow. There are iron secreting bacteria which deposit iron oxides similar to this and a lot of late roman coins have a high iron content in their bronze alloys.

Coin-Cleaning-Problem---Red-Gunk

Only the side exposed to sunlight was effected, so perhaps it is some kind of algae. Which shouldnt happen - the water is distilled, the coins free of organic matter - there is nothing to derive nutrients from. The only explanation is that its deriving important vitamins from metal salts in the water.

A good thing is that I have a good control group - a pot of other coins received recently which have had no contact with that water or that group. Ill leave them somewhere in direct sunlight and see what happens.
Pillar of the Community
jcmworld's Avatar
United States
567 Posts
 Posted 05/30/2014  6:45 pm  Show Profile   Bookmark this reply Add jcmworld to your friends list Get a Link to this Reply
Looks like adherent iron oxide sloughing off. Probably had something iron touching it when it was buried. Mechanical cleaning should pull any residuals off that don't come off in a soak. Also add some baking soda to your soak, helps get that stuff off nicely.
  Previous TopicReplies: 3 / Views: 1,231Next Topic  

To participate in the forum you must log in or register.



    




Disclaimer: While a tremendous amount of effort goes into ensuring the accuracy of the information contained in this site, Coin Community assumes no liability for errors. Copyright 2005 - 2026 Coin Community Family- all rights reserved worldwide. Use of any images or content on this website without prior written permission of Coin Community or the original lender is strictly prohibited.
Contact Us  |  Advertise Here  |  Privacy Policy / Terms of Use

Coin Community Forum © 2005 - 2026 Coin Community Forums
It took 0.23 seconds to rattle this change. Forums