Acetone

That was fast

I posted earlier in this thread that ANACS recommended using Acetone to remove PVC damage.

The information no longer seems to be on their site now that they offer their "Conservation" service for a fee.

Go figure.

biokemist6 wrote:




This seems to be the key point, but I would be interested in everyone's comments on something I experienced. I was experimenting on a gunky Hershey-brown 1950 Lincoln that happened to have a struck-through-wire line across the bust. After the "conservation," everything looked OK, but the line was now bright exposed copper. If it is true that acetone cleans organic gunk but does not react with metal, then my untutored assumption would be that the "trench" got filled with gunk before it tarnished. It's a little hard to picture how that would happen, but I can't think of another explanation. Any other guesses? Also, for this reason, or any other, would you assume that a brown copper coin with a "bright" scratch would be rejected by a third party grader? An interesting sidelight on that is that I have a PCGS graded 1914-D, a humble brown F12, that has a very tiny scratch of that nature on Lincoln's tie. I've been curious whether someone missed it, or if that's OK.

1) pure acetone will leave no residue. If you're really worried about it you could buy higher (lab) grade stuff from a chemical company, but this is likely overkill. The only issue that could possibly arise is if the acetone has picked up a lot of junk from other coins it can cause them to be redeposited on a fresh coin with drying, hence the common advice to rinse in fresh acetone before drying.

2) It might help to remove the strands, alternatively you could try rinsing them off with DI water since they might just need to be physically dislodged from the surface. And then rinse in acetone to expedite drying and avoid spotting

3) I wouldn't worry about the difference between synthetic and fabric gloves for this. Fact is, as soon as you decide to wipe/scrape the surface of a coin with any cloth, however soft, you are taking a big risk of marring the surface from whatever microscopic particulate that might already be on the surface and dragged across. In the future if you want to remove a spot or debris, I would instead recommend a high pressure stream from a lab squirt bottle or the like, since it will not risk scratching in this manner

Leave it alone.

to CCF

The following is an older but still applicable 2009 thread that focuses on cleaning copper cents. I say copper since some are made of zinc-coated steel...

Also, I agree that you should NEVER forget the following cleaning sequence which is further broken down in the thread below: 1st de-ionized H20, then acetone & finally xylene.




Best of luck

evidence - only before-test aberration is this scratch on glass:



post evaporation corroborating evidence - formation of particulate matter:



post-verdict reaction w/ plaintiff covering his face from shame after passing out from stress & excessively inhaled chemical exposure from his perspiration:



case closed-clear the jury room, the judge can't breathe...