Some more notes on the eighth plague (my original lead rot post is here), largely culled from some discussion at the Collecting Ral Partha Yahoo group:
Apparently zinc-lead alloys can have the same sort of problem (“Zinc pest“).
I don’t know if any version of Ral Patha’s “Ralidium,” which I earlier reported to be pure zinc, would have contained lead, but I think almost certainly not, since Ralidium was introduced because of the lead scare of the mid 1990s.
Also, I’ve been reading that acetic acid — vinegar — is actually a good way to remove lead rot; you just need to wash it off thoroughly. Further Update: a great blog post here more or less confirms that acetic acid, the known catalyst of lead rot, is also a good remover of it.
Finally, here is a picture of some Minifig riders (Pathans? Sepoys? Rajputs? Not sure anymore; I bought them long, long ago for WFB…). I think the middle guy has some lead rot sprouting up through the paint! (I think the white spots on the other two is just dust which looks worse than it is due to the camera’s flash.)
The weird thing, of course, is that these three would presumably all have same alloy composition, the same priming, painting, and sealing, and the same storage conditions. What the hell? I think another possibility is that I super-glued the middle guy’s lance once too many times and the excess glue, reacting with the humidity in the air, left that white residue. I’ll have to disassemble the stand and look into this.