A decent "flat clinch stapler" is worth the $10 and no pliers are needed to flatten the staple backs. I'd also spend the extra money on coated staples or even stainless steel staples for corrosion resistence in the future.
I don't like the self stick 2x2's because of the adhesive. It could get on the coins, possibly come unstuck years later and the coins drop out when you pick the 2x2 up and don't realize the glue has let go. Maybe I'm too skeptical about the self stick 2x2s but I just don't like or trust them.
Using good scissors to cut off the parts where the staples are so the coin comes out easy and safely is certainly the way to go.
If they were protected and fine inside just transfer them to new 2x2 holders, staple and label them again, but be careful to not touch surfaces sneeze or cough on them ect. Hold them on the edges touching minimally or buy a $5 pair of lint free cotton gloves. It would benefit your respiratory system and the coins to wear a dust/nuisance mask because your dealing with mold dust,abd really shouldn't be breathing that stuff in. Also this will keep a stray cough or sneeze off the coins.
Only if they have been exposed to the mold or rust and need more work to clean them up should you mess with doing it and even then start with distilled water and gently pat (blot) dry with a lint free cloth, if that don't work then try a pure acetone dip (not nail polish remover) and again pat (blot) dry gently. But only do this to the coins that really need to have it done and might really benefit from it. Otherwise just transfer to clean new 2x2 holders and new staples.
If the rusty staples stained the coin, it might be a lost cause, it's hard to get rust stains off and likely just damage the coin even worse to get them off. Of that's the case, probably call those coins a loss and put them into circulation unless they are silver. If they have silver content they are worth more at melt then 25 cents.
After that then it's just keeping them dry and check on them once in a while every (6 months or a year or so, whenever you think it's a good time to take a look at what's going on) for signs of decay of the new 2x2s or staples. If there's any issue starting, change the holders again so it doesn't get that bad as it is right now.
I think it's mostly salvageable. There may be the majority just need new holders, some that would benefit from a distilled water dip or acetone dip, and one or two lost causes, but maybe no lost causes at all. It's bad, but I've seen worse, I don't see termite evidence or rat chews lol.
Edited by Big-Kingdom
09/22/2019 12:01 pm