I have been assembling a collection of all the national parks quarters that are coming out now (and yes I know they will never really be worth anything, I just think that they are cool). I have a few of them that have a big fingerprint in the field of the design, and I was wondering if it would be ok to clean this with 90%+ isopropyl alcohol? I was thinking yes because it's otherwise quite new and isn't silver or toned.
Just a bath (no rubbing) can't hurt. I would use acetone just because that's what has worked for me in the past. If you do rub them, you will create hairlines on the coin. Based on the value of these, do anything you wish if it's fun.
You could try the rubbing alcohol. And I'll be a contrarian to @ldhair's sound advice - just this once. I think if you're very careful, you could get away with a light rub, if you use a soft enough cloth or tissue with the alcohol (or acetone). The key is not to polish the coin, but to use just enough (gentle) pressure to remove the fingerprint without making the affected area of the coin shinier than the rest of it. It's not like we're discussing a proof Gobrecht dollar or Mint State 1792 half-disme here.
Don't clean it, just find a new one! As you know, cleaning can not only devalue the coin, but ruin the luster.
So if I do a light pass with a microfiber cloth and isopropyl it should do the trick? I have some acetone, but it is in the form of nail polish remover, and thus has lots of nasty additives in it. Getting another quarter is out of the question mostly, change is kinda scarce around here at the moment
No, it won't do the trick. Fingerprints are permanent after a short period; they're etched into the coin. You could remove it with a thiourea dip, since that strips a layer of metal off the surface and the print with it, but nothing less invasive will likely be effective. If it's going to be removed by a noninvasive procedure, acetone is the chemical of choice since a fingerprint is an organic deposit. Won't hurt to try, but don't be surprised if it doesn't work.
All above is good advice, I use 100% acetone. Soak coin in it for several hours. Then while coin is still covered, very gently rub the area with a Q-tip at an angle (maximize cotton area). Remove and air dry on soft surface. Best you can do to it. Whatever is left is etched into surface.
If you just want a set to look at clean them with soap a warm water, dried off with tissue paper. You're not going to hurt them any and the value will stay the same.
