zinc pennies

[Coilcop]

Not sure if it is the soil content here in Connecticut, or if zinc is that easily corroded, and oxidized. Did anyone ever notice that when you pull a zinc penny (1982 in some cases, and 1983 forward in all cases), they are already becoming corroded, and in some cases eaten away, where part of the penny has sharp edges, or missing all together? It makes me believe, that as these stay in the ground for as long as other coins that pre-date them, they will not be found, but completely disolve!

[DougsGraphics]

Yep, they corrode quickly. Not quickly enough, though-- I get tired of digging them up! I doubt they'll last long in the ground -- natural galavic couple and all; takes only a bit of corrosion on the outer copper to get a galvanic reaction going in moist sand or soil.

[julieburger]

I got a 1961 penny today and it looked awesome and all the newer ones I find are so ate up I can barely read them.

[bigbillinsc]

saltwater captains use zinc in places all over their boats. they call them sacrificial anodes. the zinc corrodes so fast it saves other metals on the boat from rust and salt water decomposition. so yeah they are designed to rot away into nothing.

[bigjohn]

but remember indian heads can fall rite in with a zinc reading.

[julieburger]

The strange thing is I find zinc ball jar lids all the time and they have to be old and they are still together.

[bigbillinsc]

they may have a higher tin content in them julie... or maybe the ground around them doesnt have enough corrosive salts like modern fertilisers are full of. just water wont corode them and just salts (sodium, magnesium, potassium, nitrites... all of these are "salts" in the dirt) wont do it either. but put the two of em together and zinc will disapear fast.

[julieburger]

It must be the tin b/c this ground has been fertilized to death.