I bought a couple of bottles of Gordon's stump remover granules for a few bucks a bottle. There was a couple of varieties of the Gordon's, one which was a certain % of Sodium Nitrate (salt peter) and another that was 100% pure Sodium Nitrate. The pure stuff is what I bought. I picked up a steel bread pan from Goodwill for around $1.00, tested on some steel and proceeded to nitre blue some screws and pins and have used it a few other times over the years.
I read about using stump remover here a number of years ago and it works. If you have a propane burner, then you'll not have much money into the project.
