Cleaning Verdigris From Silver Coins. One Technique

Well Bad Thad, it would be nice to have access to VerdiCare in Australia ... but unfortunately not all newbie/low budget coin collectors live in the USA.

When postage (JUST postage, not for the actual product itself) is more than $24 to mail a small 60ml bottle here via your ebay store ... VerdiCare suddenly does not seem a viable solution for collectible-but-not-expensive coins that have a small amount of verdigris.

If this process gently stops verdigris on a coin that would otherwise be worthless as the verdigris progresses, then it seems a chance worth taking in my books.

In real life it actually looks heaps better. If you have some tarnished silver try it on that ( not anything with stones or pearls on it) Actually the reaction is very fast sometimes taking less than 30 seconds. I will try to post a better photo later to day

Verdigris is INSOLUBLE in organic solvents. The primary constituents in verdigris are inorganic salts.

The posted procedure will remove tarnish, it will not remove verdigris. It is also pretty much the same as usign a commercial dip. It strips the surface, but uses a base solution instead of an acid one. Either way it causes the same surface damage to the coin and if overdone will strip the luster. Bases can be just as corrosive as acids.

WRONG! First6 off it is completely different to a dip, Its a sacrificial metal process. Similar to that used to prevent corrosion on Oil rigs(Magnesium blocks) Its an electro-chemical process(like a battery). The coin I posted now has a copper sheen where the verdigris was. The soda only acts as an electrolyte. When the coin touches the the foil some of the foil is corroded while the corrosion on the coin is reversed) this includes the verdigris....Obviously there's some people here who have a commercial interest in putting people off this process. They want to make people use their product rather than something cheaper.Accordingly they are naturally biased against anything that challenges their profits. As I said at the out set I only recommended it for already damaged coins...and look how threatened BadThad was over that!!

Its amazing how commercial interests will rubbish something and misconstrue what it does so as to support their products.

Here is one of the chemical formula's that explains how the silver sulfides are affected in this process( I don't have the formula for the copper compounds in verdigris but copper sulphate is a significant component of verdigris):


3 Ag2S + 2 Al --/> 6 Ag + Al2S3
silver
sulfide aluminum silver aluminium sulfide


Actually I found another name for the process Electrolytic cleaning:

See this entry in Wikipedia and scroll down to Electrolytic cleaning don't be scared of the term "Galvanic corrosion" in this process it is the Aluminium foil that is being corroded

I would suggest the verdi care people stop pushing on this one because some of the research I have done to check how the aluminium foil actually works suggests there are some very real concerns about verdicare Such as: As you remove the verdigris you must be removing some of the coins original metal.

You going to yell at the maker of the 2x2's for the distributor's high shipping, too?

There have a couple posts by people offering to ship it to members overseas, one by a mod if I remember correctly. Take them up on it if you want to. You lashing out at a manufacturer because of the distributor's policies/ship charge is just plain ignorant.

Regarding the foil 'technique' - while it's great for tarnished silver, what you aren't realizing - or at the least did not state - is that the process takes a bit of the silver with it when it moves to the foil. Your first sentence needs to be bolded and enlarged: This is a chemical process and should only be used, IMHO, for gap fillers where you wish to prevent further deteriation and stabilise the coin. It's a harsher method than a dip. It sounds like you're very new to it, so I'd suggest you proceed with a great deal of caution if you're going to keep doing this to coins.



Yes. We like our coins undamaged. Sooner or later the ones being killed of any numismatic value in this manner are going to leave your hands, and in the same manner that caution is urged against any other harsh method, other people will warn against it. So yes, I believe many have a commercial interest.

... was going to be my last public post on this thread except for the comment posted by dei gratia regina eight minutes ago while I was writing that posting.




No, it is not "just plain ignorant" of me, and again I am surprised at the insulting language being used.

I raised that point not through ignorance, but purely BECAUSE of my knowledge of the standard postage fees I have paid over the last ten years for many different sized items posted from many different countries. I have bought many items from America - and most have been much bigger and heavier items than a 2.2 ounce/60ml bottle - and have ONLY ever paid a reasonable price for postage.

Over $24AUD IS ridiculous and overpriced.

And by the way, "ignorant" is not an insult. It means uninformed or having no knowledge of something.