To be honest, I have no idea how to do the plating process. I'm assuming it would involve some kind of electrolyte, some hunks of zinc (those I have, in abundance - I have a boat that needs new zincs twice a year, and I have a pile of partly-dissolved ones), and some amount of electrical current. I'm sure it wouldn't be too difficult, aside from the obvious issues of having a big enough vat to submerge something 12' long or so.
In order to do it right, though, the best way would be to drill holes in every single tube, so the electrolyte can get everywhere, including inside all the tubes.
Interestingly, Porsches from the late '70' onward were fully galvanized. Once the entire frame/body were built & "in the white" (no coatings etc., just raw steel), they were carried by an overhead rail down into a tank, fully submerged, and plated inside & out. Even here in the Pacific northwest, where salt & moisture are airborne 24/7, these cars simply never, ever rust...unless they've been damaged & had bodywork. Then, all bets are off.
Anyway, at one point galvanizing my Locost was a dream (okay, maybe a pipe dream...), but I'm learning that simplicity is a virtue. You might not know it from my build, but I'm learning.
My buddy insisted my cooling system wasn't going to work, that I needed a remote pressurized expansion tank, a remote filler neck, see-through bleed-nipple adapter, dual chrome-lined reverse de-coupling framulators, cooling-inversion gespatcho-stimulator modules, and a bunch of other stuff I didn't understand.
Then, I pointed out that my radiator cap is already the highest point in my cooling system, so if it worked in the original Ford Focus with nothing more than an overflow bottle, it ought to work for me, too, right? See - I'm learning!
_________________
Scratch building, at continental-drift speed, a custom McSoreley-design framed, dual-Weber 45DCOE carburated, Zetec-engined, ridiculously fast money pit.
http://zetec7.webs.com/