Yes, nickel will plate onto iron, and assuming your handles are galvanized, that's probably the only metal in them underneath the zinc. I was looking
into making my own soldering iron bits, and my research indicated that to do it properly, you have to plate the copper bit with iron, then plate
nickel onto the parts that you don't want solder to wet.
Really though, with electroplating, a major concern is metal atoms diffusing through the various layers, which is why nickel is typically put down as
a base layer, since it's pretty good at keeping metals from diffusing through it. Copper is then plated onto nickel, because it works the best for
further plating with gold and chrome. (Hence the reason cheap metal stuff turns a copper color when the chrome plating is worn away) Silver is really
bad about diffusing into other layers, and I'm not sure you'd be able to plate it onto iron anyway. You can't plate silver directly onto copper
either, or it'll turn a splotchy bronze color after a few days. I believe you can plate it onto nickel without any major problems, except for the
fact that in order to properly silverplate anything you need its potassium cyanide double salt. Same goes for gold. You can purchase plating
solutions that take away a lot of the risk, but you seem more interested in making your own plating solutions, in which case, nickel is probably the
way to go.
As far as the sulphate ion, the reason they use it is because it does virtually nothing in solution except carry a charge. In the rare instance that
it gets oxidized to O2 and SO3, that SO3 doesn't waste any time reacting with water to form H2SO4 again. Usually the potential is too high for that
though, and you just get oxygen at the electrode. |
