I have this 1921 S Lincoln with what looks like glue on the obverse. What is the best way to remove it? Or, should I leave it alone? If I dip it will the dip remove the patina and reduce the desirability of the coin? Thanks for any help.
Like with most copper coins, start with a few hours in water to see if anything losens up, then dry it and switch either to acetone or xylene for a few hours, otherwise leave it alone.
I think it's probably old glue. @Kentucky's advice seems sound to me. Unfortunately, even if you successfully remove the gunk without altering the existing toning on the coin, you still run the risk of having the "protected" areas that were beneath the deposits being brighter than the rest of the coin afterward. But it's worth that risk to get the stuff off, I think. If there are brighter patches afterwards, then we can discuss the possibility of retoning with a Vaseline and sulfur paste- something like Deller's Darkener.
Thanks for the advice. It is not a high grade coin. But, it does have great eye appeal and character, 2 attributes that I enjoy.
Looks more like solder than glue. Soaking it won't have any affect at all. The problem is, once you remove that stuff the areas that were underneath it will have a very different appearance. It will not have great eye appeal on the obverse at all, as LordM mentioned.
