TIL that George R. R. Martin has a miniature collecting web page that covers lead rot.
https://georgerrmartin.com/for-fans/knights/comments-on-collecting/#lead
He summarized Bert Caldwell’s article in TOY SOLDIER AND MODEL FIGURE #13.
Causes; humidity and poor air circulation
Solution to stop it; 50/50 turpentine and mineral oil
I mixed some up and doused some recent eBay buys that had a light white dusting. Now I wait a week for them to dry and I'll try primer on them.
Here are three identical #StarFrontiers battleship #miniatures after varying amounts of treatment with Rochelle Salt.
The topmost ship had the most #leadrot, and needed 10 minutes treatment to remove it all. The middle ship only needed five minutes treatment, and the bottom ship hasn't been treated at all.
Anyway, back to progress photos. This spaceship is the only miniature so far that I had to treat for 15 minutes (three five-minute Rochelle Salt baths, with scrubbing in-between) to remove all the #leadrot. Scarring is severe, but the ship is structurally intact. I can maybe still use this for something.
And that chart also references lead *formates*, corrosion produced when formic acids (which like acetate, can be found in carboard), act on lead. As this photo lifted from https://www.mdpi.com/1996-1944/13/24/5672 shows, lead formates (and lead sulfides) are darker than acetate/carbonate corrosion. It makes me wonder if the darker #leadrot seen on some #miniatures is a combination of different corrosions.
Not that it would matter much to me. Rochelle Salt dissolves almost every type of lead corrosion.
According to the famous "Navy Ship Model" article, the white #leadrot we're all familiar with is a combination of lead acetate and lead carbonate, triggered by acetate fumes from (among other things) cardboard. https://www.navsea.navy.mil/Home/Warfare-Centers/NSWC-Carderock/Resources/Curator-of-Navy-Ship-Models/Lead-Corrosion-in-Exhibition-Ship-Models/
But, as this chart from https://sciendo.com/article/10.2478/kom-2021-0013 shows, it's not *that* simple -- varying levels of humidity and fume exposure can create different combinations of corrosion, which I suspect might be why some #miniatures are easier to clean than others.
A major (but seldom acknowledged) problem with understanding #leadrot is that there are several varieties of lead corrosion that *could* affect gaming #miniatures, but no easy tests to differentiate them. One study I'm referencing had to use "infrared spectroscopy" and "x-ray diffraction!" My lab (the remnants of my childhood chemistry set) doesn't have an infrared spectrometer.
I've encountered a new phenomenon while using Rochelle Salt to clean corroded #miniatures. This spaceship had a lot of white corrosion (which most sources identify as the earlier stages of #leadrot) but the corrosion turned black after a few seconds in the solution. There's some chemistry going on here that I don't understand, because I'm not much of a chemist.
Tested Rochelle Salt on another batch of gaming #miniatures -- some scarring/pitting on some minis, but nothing I'd call ruinous. A few #StarFrontiers aliens mysteriously darkened in color, which is something I need to think about.
Even so, I'm feeling confident enough to continue processing mild #leadrot cases this weekend, and then I'll go back to experimenting with the more severe (and more unusual) figures next week.
Rochelle Salt was more effective at cleaning #miniatures that haven't reached the "tumorous" stage of #leadrot. After a 10-minute soak, the corrosion on this #StarFrontiers mini could be scrubbed off with a toothbrush. The miniature lost 0.05 grams of mass.
My preliminary test of a Rochelle Salt solution for removing #leadrot from gaming #miniatures shows some promise. After a 10-minute dip for two highly-corroded minis, you can see corrosion coming off as I dry them, and they (together) lost 0.1g of mass.
Nothing will really save these particular miniatures, but I should test the process on early-stage leadrot next.
I am reading some very sciency articles while I contemplate the problems of #leadrot in gaming #miniatures, and considering ordering chemicals I probably shouldn't play with. I was an anthropology major, for God's sake!
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7764096/
(My wife isn't discouraging me, though, because she has far too much faith in me.)
