Fingerprint on SBA proof - how to remove

[pendragon1998]

I just got a 1981 proof SBA in the mail that I ordered off ebay. To my delight, it has what appears to be a fingerprint covering about 10-15% of the reverse.

 

I'm normally very opposed to cleaning coins, but this coin isn't expensive enough to justify the postage needed to return it, and it's a fairly new coin with no toning to protect. Is there a way I could give it a quick dip in something to remove the oily residue?

[James_OldeTowne]

I would think a quick dip would solve the problem. Possibly consider using something called "MS-70", as I know of at least a couple of proof specialists that have helped coins with it.

 

James

[MunkyMan95]

You might also try heptane. Heptane is a chemical used in oil analytical labs to clean oil off of any instruments they may use. Since fingerprints are oily, it should work. I have used this on my coins with no ill effects. Don't be surprised if you have to soak it for a few days, though.

[Jazzy]

Send it back.

[pendragon1998]

Well I would, but the coin's worth perhaps 8-9 bucks, and I already paid $8 + $2 for shipping. I'd get refunded for the $8, but it'd cost me several dollars to ship it back, at which point, I'm out $5 over an $8 coin, which is becoming ridiculous. I'd rather just take my chances cleaning it.

 

Isn't heptane carcinogenic? Would acetone work?

[jason888]

i`d send it back, very common coin. u can send it first class in padded envelope for .63 cents.

[mhardin2413]

cut off the genius's offending finger. that's one way to get rid of fingerprints for good.

[pendragon1998]

Okay, let's just say I'm curious to try cleaning it. I've got one vote for MS-70 and one for heptane. Can anyone else give me any ideas that don't involve shipping it back or going to jail for assault?

 

Currently, I'm thinking of using some lab grade ethanol and just gently running it over the coin using a squirt bottle or possibly soaking it in a small, clean beaker. Then I'll rinse with deionized water and see where I am at that point. If for some reason I get spotting as it dries, I'll rinse again with deionized water then hit it with a gentle stream of compressed air from a distance to blow the residual water off. I'll be doing this while wearing neoprene lab gloves.

 

If that doesn't work, I'll try to round up some acetone at the lab.

[James_OldeTowne]

Proof coinage is one area where acetone is a risk. I understand it can haze a proof coin's surfaces. However, I am guessing that if you acetone it, then do a very quick dip, then neutralize it, you'd be in good shape.

 

I'm am NOT a dipping expert, so regard my suggestions with a grain of salt. This is just based on listening to what other collectors / dealers have suggested over the years.

 

James

[pendragon1998]

Well, I did it. I soaked it in a small beaker of 200 proof lab-grade ethanol, then rinsed with deionized water (di). I ended up with a haze, and it didn't remove the fingerprint. Next, I pulled out the industrial-grade acetone and repeated, again rinsing will with di. That removed the mark, but left the reflective fields still hazy, with repeated water rinses not improving things. This wasn't acceptable, so I spent 20 minutes with several kimwipes (lint-free towelettes meant for optics) and basically breathed onto the coin to fog it up, then carefully wiped the surfaces clean. I'm about 85% happy with the results.

 

I was able to remove the fingerprint, which was the major detractor from the eye appeal of the coin. I did, however, end up putting on some micro-abrasions, mainly on the mirrored surface of the coin. The micro-abrasions are barely visible with the naked eye, and are noticable under 6x magnification if the light is angled right.

 

Like I said, I'm 85% satisfied with this coin. I think it looks fine - not a perfect coin, but much better than when I received it. I've also gained experience in determining whether a coin's been cleaned, and learned a little bit about cleaning. I'm going to take some time before too long and try cleaning some non-proof current-issue coins just to see what happens. I still think cleaning is inappropriate in upwards of 95% of situations, but I'm glad I cleaned this one.

 

My current collection goal is to complete a full set of all SBA dollars in the best condition possible, so for now this coin's going to be a place holder. I think a SBA collection will be an entertaining (yet affordable) goal with an end in sight in the next few year or so.

[TomB]

I would have suggested sending it back as this way you would be out a few dollars but wouldn't have to boink around with an impaired SBA that will bother you each and every time you think about it the rest of your life! For the difference of a few dollars this was worth it very much.

 

You needn't have used a higher technical grade acetone since it would not have been any "stronger" than reagent grade acetone. Also, using Kimwipes killed the surfaces of the coin, regardless is you have noticed it yet or not. Kimwipes are mighty rough and proof surfaces are extremely fragile.

 

Next time, send the coin back.

[Here]

Since it didn't really cost you that much why don't you use it as a pocket piece? Then in 5 years send it into NGC to be graded. That'd be kind of fun.

 

 

 

Jerry

[jgrinz]

MS70 "would have" worked great with finger prints - Mostly ammonia and soap minor chemical constituents.

[pendragon1998]

I would have suggested sending it back as this way you would be out a few dollars but wouldn't have to boink around with an impaired SBA that will bother you each and every time you think about it the rest of your life! For the difference of a few dollars this was worth it very much.

 

You needn't have used a higher technical grade acetone since it would not have been any "stronger" than reagent grade acetone. Also, using Kimwipes killed the surfaces of the coin, regardless is you have noticed it yet or not. Kimwipes are mighty rough and proof surfaces are extremely fragile.

 

Next time, send the coin back.

 

I was really just curious how it would work out and wasn't overly worried about destroying the coin. I certainly won't be worrying about it for the rest of my life ;-) Next time I'd send it back, though.

 

I wasn't thinking the higher grade acetone would be stronger, but was hoping it would be more pure.

[errorist]

A few drops of Olive oil and a little toilet paper works wonders. I sent a coin in one time after doing this and the finger print was gone and the coin came back PF-68 deep cam.

[Coin]

I'm glad you cleaned it. In fact , I am very very happy that you had the gusto to go for it and try an experiment and learn from it . At least you used a somewhat common coin that will more than likely never end up being traded at an unfair price and tricking an 'expert' into thinking that it is rare and valuable.

Some of the replies here seem to be on the edge of dispise for you trying to learn something...as if they are saying do it my way only or else...and if you don't listen to me then pass on ya.

Folks , with 20 years experience in the millitary , I've learned that there are actually some people that get so consumed and curious that the only way they can possibly get a concept is by Hands-On learning (OF course you don't want them in a demolition class ).

In the future , however , I would have suggested getting a 'control' group of common circulated clad coins from pocket change and trying the different methods you worked out....even getting some of those cheap 82S Washington commemorative 50 cent proof pieces ( about $5 each at any coin show and most magazine ads) and intentionally screwing them up with grease and oils and other grundgy stuff ...then letting them sit a while . Later go and fetch them and have at it. Try every reccommended technique ever posted on this board's threads.

You'll probably ruin a few coins , but hey -they'll still be worth face value at the local market- and you'll learn ,hopefully, enough to satisfy your curiosity and maybe be able to post something about it .

We are talking about common coins though and I only mentioned the 82 proof as one of the cheap big coins ( cheap proof set coins will work too).

I would not reccommend that you destroy any rare or highly collectible coin during any of the experiments for fear that it would likely cause the death of many a board member should they ever find out about it.

Remember , this is the kinder and wiser chatboard site , I am sure that the members were only trying to help and not deter you from finding out any secrets . They just sometimes don't take the time to word everything out to you. Good luck with it -I'm glad you learned something .

PS , Mike(jgrinz) is right , MS70 woulda worked on the prints without having to wipe hairlines into the fields like TomB said. Keep in mind , some older prints leave surface damage and can not be completely eradicated .