Before the early 1990s, most miniatures were made from a lead alloy which can be affected by Lead Rot.
Lead Rot is caused by dampness, which cause the surface of the lead to go powdery (a bit like rust), but can if unchecked, make a miniature turn into a lump of rotten metal (not to be confused by metal bloom which is caused by the overheating of the lead alloy in the casting which blackens the surface of the miniature which is perfectly OK). Lead Rot cannot be cured, but can be stopped.
Stopping Lead Rot
Antique restorers used the following procedure on lead antiques which also works on lead miniatures.
- Soak overnight in white wine vinegar.
- Boil in de-ionised water.
- Wash and clean between each process.
- And then repeat.
It will take a long time to do and some details on the miniature will be losted (or fall off), dependent on how much the miniature has been affected by Lead Rot. The Lead Rot will go soft slowly, so you will need to repeat the process. You can help to speed it up by using modelling picks and files.
There are a number of other ways to deal with Lead Rot, check out the links below.
The best way to keep lead unpainted miniatures is not in a damp environment (or in wooden box), but the very best way is to paint them (or at least undercoat them), especially if you taken days to remove the Lead Rot.