How I cleaned this steel penny...

[RyanChappell]

That war penny looks amazing!!!

Make sure you get all the acid off. I would neutralize it with baking soda solution.

Originally Posted by DIGGER27

Yep. Copper and steel...two completely different metal types.

I think the steel ones are coated in zinc, but it does look like the iron in the steel is leaching through the zinc and leaving rust on the outside. From my experiments with Zincolns with holes in the copper plating, zinc reacts very strongly with lemon juice.

I think the results depend on microscopic pits and cracks that are probably all over IHs and old wheats.

I still think that tumbling is the way to go on restoring old wheats that are pitted, because it wears off a small layer of the coin fairly uniformly, like circulation, and maybe it even fills in the holes with ground up copper?