MINIATURES REFERENCE:
Preparing

Lead rot does happen over time, especially if the figure contains a high bismuth mix within its alloy.

A way to prevent this effect is to soak in vinegar overnight when you first buy the figure, and then wash with warm soapy water and rinse thoroughly.   Allow to completely dry, and then prime even if you can't paint right now.   The rot comes from oxidation of particles on the surface of the miniature.   Soaking in vinegar removes the existing oxidation, and the priming seals the miniature from the air necessary to cause future oxidation.