david weaver
Thanks for that. I have two of the ingredients already and ordered asphaltum to give it a shot.

I wonder what makes the "store bought" version cure without the oven. Japan drier?

Japan drier in Japanning?

Todd's version requires heating to 450 or so (degrees F), which I can't do in the house, but may get a toaster oven to facilitate if japan drier doesn't work. If nobody knows, I can try it and report back. I've never used japan drier, but am getting weary waiting for sunlight with a violin varnish recipe, and will have it on hand.