I originally used about 10% Manganese Dioxide in my mix but it went bad last year. I don't know what happen, as it started to melt a bunch of black foam kept raising to the surface. When it was all melted I poured it out. my new batch is from Brownell's. it seems to work fine. As far as I know there is no MD in the Brownell's. I have a large pot and small one I made from a iron 2" end cap that I removed the threads from. I use it for small parts like pins and screws so the small pot is very handy.
