I just melted down the inside of my waste oil forge. My fault,.... I knew I had to re-line the inside with some new refrac, but thought I could get one more session out of it.......riiiiighht. The forge body was essentially reinforced concrete molded around refrac. The burner was nothing more than lava rock with a gravity fed fuel and injected air from a compressor. It worked well enough, I could get a peice of spring steel stock (1/2 x 2 x 6 inches) up to non-magnetic in about a minute. Fuel usage was about 1 quart every 20 to 30 minutes. I could use a variety of fuels from motor oil, hydraulic fluid and such to used fry-oil and would get up to working temps after 10 to 15 minutes. I guess I should of seen what was comming when I had to chip the glassed lava rock out, Huh? Jim L.