I have a collection of Barber quarters that I inherited from my grandfather. They were stored in a really old Whitman folder (the copyright date is 1940). I took them out (very carefully) to examine them, and every single one has really dark vertical lines on the reverse from the glue on the paper. These coins are almost all G-4 at best. They're all extremely worn down, and in some cases the date is barely visible. Most of them are worth less than $10 in their current condition. There's a few exceptions, most notably an 1892-S and an 1896-O. Barring those exceptions, I'm wondering how much further damage I could possibly do to these coins with a quick dip and a cleaning. I'm well aware of the prohibition against cleaning my coins, and I haven't done anything to them yet. It just seems to me that dipping a G-4 coin is only going to make it prettier, especially with the ugly lines on the reverse of all of these coins. Thoughts?
I suggest you try dipping one in acetone, which is generally very safe to use on coins, to see if it helps. Just take precautions not to breathe the fumes, and be aware that acetone is highly flammable, and will damage some items.
Don't forget that beauty is in the eye of the beholder. And just about any collector who looks at a G4 coin is going to expect to see that coin a toned color, not bright and shiny. Glue on the other hand should be removed, acetone is the answer. And if acetone doesn't take it off - then leave it.
You will likely destroy a good portion of any numismatic value that these coins have individually and may reduce their value to you as something representative of your grandfather. I am quite familiar with the effect that you are describing on low grade coins from these Whitman albums, but I doubt you have glue residue on these coins. It is more likely that the glue affected the rate and type of toning that occurred on the reverse of the coin and that these stripes or lines are deeper toning lines that are not glue. My suggestion is to leave them as is and, if you are determined to mess with them, simply sell the set and allow someone else to enjoy your grandfather's collection.
Circulated coins, particularly in G condition, virtually never look better after being dipped, IMO. If I were you I would leave them alone in the Whitman -- if it is the Whitman I'm thinking you can only see the obverse anyway.
Thanks for the feedback. It didn't occur to me that an old G-4 coin would look worse from having been dipped, but I do believe you're right. These coins are so very heavily worn that having them look all shiny and new would be very strange. I don't think there's any actual glue on the reverse; like Tom B said, I think the glue just affected the rate of toning. The reverse of these coins is really ugly, but as long as I leave them in the folder it's not a big deal.