Buffalo Nickels

Nic a date! or a long soak in white vinegar. However, both causes damage to the coin. If done properly, a nickel with a restored date will look somewhat presentable. If done improperly, over time an ugly dark spot appears where the nic a date was applied. (I probably have $20.00 worth of Buffalos I used Nic a date on when I was much younger and less wiser)

Nic-a-date, a metal etchant with ferric chloride as the active ingredient, works in a matter of minutes while the vinegar is a slower process since it is only 5% acetic acid.

"How long of a soak?"

I tried a few with vinegar and it took between a few days to several days. I think 7/10 were restored enough that I could read the date, but some were very tough to read. My best advice (if you're going to try it) ask your coin dealer for some dateless buffs, if he/she lets you look through them first, pick out some with mintmarks, if there are any. You can also tell if they are the Type 1 "raised ground" which were only made in 1913, without restoring the date at all.

Oh yeah, make sure that whatever you're soaking them in doesn't run out of vinegar, or get too low, otherwise you'll end up with blue stains on your nickels.

My coin store sells them for about 20c each.

I use nitric acid to restore dates. Very very cuastic stuff and should be used with great caution, golves and protection of the table or surface. Only needs 10 seconds on the date area. Probably restores half to 3/4 of dateless nickels. Some the date can be read easily, some take two treatments and still have to tilt it in the light. Typically, if you see less than half of the "Liberty" showing, it won't restore successfully. I'd probably try it out on a few dateless with no mint mark to get the time down and then go to the ones with mint marks (where the money coins are).

I've never tried acetic acid (vinegar).

20 cents apiece for dateless is fine. Grey sheet bid is 15 cents apiece. From what I've found, dateless lots sometimes have partial dates in there.

Happy hunting.