Originally Posted by
Winger Ed.
I've had Iron molds do that. I think the heat does it.
I think these Iron molds get seasoned sort of like Grandma's old cast Iron frying pan.
All my molds are pretty old and well used by now, and don't remember seeing them being purple any more.
Like Grandma's frying pan, they're all a solid black and don't change or add any new colors.
My newest mold is a Lyman DEWC, and I got it used.
It came in with a few heat marks on it, and the area around the hole for the boolit was purple.
But it went away after the first 1/2 coffee can full of my production.
I don't know what difference it makes, but I do run my pot on the hot side.
I crank it up to start, then turn it down a little at a time until I have just the barest hint of frosting.