Treating problem coins with oil.

Hey gang!

I know there are a LOT of coin purist out there. I appreciate your position. Here is a position that I am sometimes confronted with. From time to time I come across a collection of coins that was improperly stored... either in PVC holders or in a place with lots of moisture... say a basement.

I see coins relatively often that end up green and look like the coin below. In this condition I think everyone would agree that this coin is not collectible.



Depending on the cause of the "green" whether it be PVC or light verdigris I have found that applying a light oil... such as Coincare can dramatically increase the eye appeal... and value of such a coin.

This coin came out of a collection that was stored improperly and ALL the coins were varying degrees of green. The coin was soaked in acetone and what was not removed was removed with a que tip covered in Coincare.

Here is the final result.

 

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The acetone ok, but my question sir is how long the oil will last? If its not permanent like the acetone dip taking the contamination away, what will your buyers think when their pretty brown coins turn green again? This is what I worry about, the long term affects of the oil on the surface, and if in 5 years it will revert back to previous condition.

I don't know the answers to this, I just bring it up since the coin industry has long memories it seems, and you wouldn't want to be known as a coin doctor. Would this coin slab? How would the TPG feel if it turned green in their slabs in 5 years, like the putty incidents a few years ago they had to make good on.

That's all sir, and if everything I just wrote is not a concern, and this is a great long term product I apologize is I brought up unwarranted caution. If it is stable and a good long term product I would like to know about it.

Chris

 

I have coins I have done this to for more then 10 years that have not reverted to this state. I believe it's the state in which you store the coins that will cause further issues. From my experience it seems to be permanent towards heavy PVC contamination. (which is what's on the coin shown). It also appears to be the same for light verdigris.

 

I am not a purist so I have no problem with conserving a coin, as you did, to make it presentable. Although a purist would say you removed the patina by cleaning it, you only removed the undesirable aspect of the patina.
Rust on an old car is original patina but you don't leave it on a car for the sake of keeping it original.

 

Thanks for the post Matt. Do you know if "coincare" similar to "Blue Ribbon"? I have not seen Blue Ribbon for sale & I wonder if the brand owner still offers the original product. (I used to have his business card but apparently I've lost Chris's contact information).

 

So do you believe the oil is removing the green toning/residue? I don't have a problem with that at all. Sorry if I seem squeamish, its just when I hear "oil" I immediately think of things like gem cutters adding oil to emeralds to hide inclusions, and similar things. Oil can hide problems for a while, just for them to come back when the oil leaves. If you think the oil actually removes the contaminant, then I think its better than the alternative.

Chris

 

Chris,

The cotton swabs are always green after use. It definitely removes the PVC. Coin care and blue ribbon can be used as what I call "coin make-up" for coins without issues... basically adding it to a coin that might not need it can make it look better then it really is. However it can be used as I'm using it to remove surface debris and contamination.

Here is another I did that would have no problem grading at a TPG. It's common... and not in high grade.. but it would definitely grade.

 

Ok sir, fair enough.

 

This is a great method for improving eye appeal. The oil itself will likely last longer than the collector.
I've had collections where coins were oiled and put into slips 30 or 40 years ago and there doesn't seem to be any difference between the ones that I have recently treated this way. If anything, certain oils will develop an unpleasant smell over the years, but appearance seems to remain

Aside from pvc/corrision spots, this also works well on coins that have developed funky colors due to chemical cleaning. It evens out color variation and dulls that unnatural iridescent color that dipping can cause.

One small note when using it on copper and bronze: You may want to lightly wipe off excess oil with a soft tissue. It will leave enough to have the desired "cover-up" effect, but will not make the coin so glossy as with that Hong Kong cent.

 

Doug,

The first coin had an several hour soak in pure acetone. It was changed 3 times untill there was no more green in the acetone itself. I think the acetone got all it was going to get.

 

I would use acetone to get the visual verdigris off first, then use a light oil to neutralize whatever microscopic particles remain so it doesn't return. Even using acetone again to get most of the oil off leaving only traces in the pores of the damage. Much like pulling a weed and leaving the root, you have to spray it with poison, or it will return. The coin is still damaged at some level, sure, but not a total worthless coin like the before picture.

Either pick up a coin raw with a little schmutz on it and remove it yourself or probably pay someone a premium for doing it before you saw it. JMO Matt

 

I guess I should stress that you should NOT just start going and oiling your coins. Their are special circumstances that dictate when I do this. Coins with heavy PVC contamination or coins with light verdigris are the ONLY coins I would even consider doing this to.

 

Matt's pics are VERY useful for detecting coins that have been boinked with.

Notice the even brown coloration with wear -- that's the key feature of these worked coins that every copper collector should become familiar with.

I am NOT judging or saying what Matt did was wrong -- it's his coin and he can do whatever he wants with it, and frankly it looks much better after the work -- but rather just commenting on the look that results from this work.

Thanks for sharing....Mike

 

Unfortunately, the problem still exists, it is simply masked by the oil. Verdigris is primarily composed of inorganic salts that are insoluble in acetone and oil. Your acetone soak may have turned slightly green, but it only solubilizied some of the acetate based verdigris and to a very slight degree some polar consitutents.

Other than that, you physically removed some verdigris with your qtips but it is still there clinging tightly to the surface. The oil simply masked the root problem. Also, oil contains metal reactive impurities such as sulfur, phosphorus and chlorine. Over time, these will react and cause changes/damage.

 

I like your reply and agree with you.

 

Doug,

I agree with this statement completely. The situation I face is that coins presented to me have not always been stored properly. I face the decision to either leave the coins be... in an noncollectable junk state because of their previous owners poor storage decisions, or to experiment and look for a way to conserve the coins to a state... that while not perfect... and somewhat controversial may still be collectible.

Those of you that know me personally know that I believe in full disclosure in my business. I have no problem divulging my conservation methods for everyone to see and to comment on as I have done here. I will say that this is not the norm... I would say that 95+% of the coins I see require no conservation at all. Some coins require an acetone bath, some coins require a well executed dip (GASP!), and some coins such as the ones posted need more.

I'd love to hear of other methods folks have used with similar coins as the point of this post was in the spirit of education...myself included.

 

This isn't directed at Matt speciffically, I am just talking out loud here.

I am on the fence with the oil on the coins. At what point have you gone too far? What's next? Re-browning a coin? I see certain sellers on ebay who buy discolored cents or verdigris, or problem cents and then clean and oil them. They resell them under the same account they buy the other ones form. It is very deceptive. Or is it?

I also have been fooled and bought a terrible "re-colored" copper coin.

I am all for removing PVC damage though. I have had to acetone and even dip some due to extreme pvc slime (silver). As far as the example the OP has in the post, it certainly does look nicer after the oil. However, I do not know about the underlying problem, or whether or not it still exists. It's really a fine line to walk. Depending how many beers I've had, I can fall to either side at any step.

Here is the "re-tone" disaster I purchased.

 

Well said sir. I believe anyone who reads your posts are aware of your upstanding attitude and full disclosure. You are truly an asset to this board, and I am glad to make that statement.

I have found this thread informative, and glad you started it.

Chris