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 Replies: 11 / Views: 4,115 |
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New Member
Australia
1 Posts |
Hi everyone at CCF! HELP! My newly acquired 50 cent silver coins have developed mould spots on them, which seem to be growing. Arggggg. I live in the tropics, & thought I had them stored properly. What can I do about restoring them? I gave them a quick wash in some hot, soapy water (I know cleaning is a no-no, yet at this rate, these coins will be useless), and the mould didn't budge. It looks like its eating into the coins. What can I do? If anyone has any tips, they would be quite welcome! Thanks everyone  |
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New Member
 Australia
1 Posts |
ps - not sure if I posted this in the right area or not? Still new to CCF, my apologies if it's not correct.
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Bedrock of the Community
Australia
21786 Posts |
moonglow: Welcomre to the CCF!
If the 'mold' is organic, soaking in acetone should remove the spots.
I suspect that the acetone treatment will not be successful. They may be black spots of silver sulphide. If that is the case, the spots are about as difficult to remove without damage to the coin, as verdigris is to remove from copper or bronze coins.
Fortunately, Australian 50 cent coins are not worth much above their silver value, they made over 36 million of them, and are certainly not scarce by Australian standards. For this reason, cleaning them would have very little impact on their value. These coins are strictly traded on their silver value only.
Cleaning them with 'Silver Dip' or similar should remove the sulphide spots, but the coins will very obviously look cleaned. At least this case, you won't lower their value by much. If they were my coins, I wouldn't go down the 'Silver Dip' path.
What you must do is change the storage environment, and if living in the tropics, store them with silica gel, preferably in an airtight container.
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Formerly nancyc
Australia
5385 Posts |
If you're going to try acetone, be sure to get the pure acetone from a Hardware store (Bunnings) and whatever you do, don't use nail polish remover. It contains a lot of other nasty chemicals that will not be kind to your coins.
life is a mystery to be lived not a problem to be solved
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Moderator
 United States
188415 Posts |
 to the Community! I moved your topic to a more appropriate forum  |
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Pillar of the Community
Australia
877 Posts |
If it is tarnish (silver sulphide) and you are really desperate you could try the old technique of bi-carb soda, aluminium foil and hot water -Google "silver cleaning" for a multitude of pages describing this.
But first read this http://www.hermansilver.com/care.ht...ctrochemical. Then decide. Lots of good information on this site about silver. One thing to beware of is proximity of rubber. Sulphur is used to vulvanise rubber it can tarnish silver very quickly. I learnt this when I sat a round 50ยข on the rubber mat on top of my set of storage drawers (I think it may have been damp). Just a few seconds was enough to substantially blacken one side of the coin.   I endorse Nancy's recommendation about acetone and Sel's about silica gell. Acetone is good for removing sticky goo; adhesive, blue tak, chewing gum etc. but will have no effect on tarnish. If it is mould then you should see by viewing against the light. Mould will show as a build up on the surface. If the surface is OK, but discoloured, then it is a stain or chemical reaction. Boiling water should kill and loosen mould but the mould will probably leave a discolouration.  Jeff |
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Valued Member
Australia
191 Posts |
I know people say never clean your coins however this is probably the exception to the rule (assuming your talking about 1966 50c coins), unless your coins are UNC they are worthless (numismatically), their price is linked to the spot sprice of silver, therefore I would try some soapy water and removing any spots with a cotton bud. In future try to store them somewhere try and at a constant temperature (I note that dry extends to somewhere which won't be effected by humidity). If the damage is starting to pit your coins then maybe you can try using some disolved chemicals in water, I know some people use lemon/vinegar to clean copper (maybe others can help you with an equivalent for silver).
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Pillar of the Community
Australia
7096 Posts |
With sel these are not a great numistic coin, They are like a---holes, everyone has one. If you can get a few unc ones put them in airtight storage with silica gell and keep them for 50 odd years and they may become a numistic item. At the moment they are just bullion coins, Don't get me wrong they arn't rubbish (80% silver) and well worth hanging onto but they don't command much of a premium over spot silver price . By the way |
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Rest in Peace
United States
9104 Posts |
If it's actual mold (mold eats organics, not metal), try hydrogen peroxide, available in the health + beauty aid department.
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New Member
Australia
1 Posts |
Hi everyone Thanks so much for the feedback. Much gratitude. It's certainly given me food for thought. I had the coins stored in plastic sleeves, which I assumed were PVC free. We've had up to 85% humidity lately, so I am taking it that maybe the coins + humidity + plastic have caused the reaction. When I washed them in the soapy water, I actually gave them a light scrub with a soft toothbrush (given I had nothing to lose!), & it had no effect. I'm leaning towards the acetone treatment, (this stuff is tough & not easily scrubbed off) & Jeff's bi-carb treatment. Jeff, I have actually seen that on Youtube, never thought I would be doing it on my own coins! Will post further when I've tried some of the suggestions here, & let everyone know how it goes. Thanks once again everyone for taking the time to write back. A great forum, & a great community of people |
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Bedrock of the Community
Australia
21786 Posts |
There are lots of methods of cleaning for silver flatware and tableware, but coins are different. Flatware and tableware do not have mint lustre, which is greatly appreciated on coins.
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Pillar of the Community
Australia
841 Posts |
I haven't tried it but they say a little teatree oil in hot water is good to kill mould but I'm not sure how it'd go on coins..I suppose if you have nothing to lose why not.
5ml/L for foot paths etc..I must try it : )
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Replies: 11 / Views: 4,115 |
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Posted 11/24/2011 01:08 am
