Thanks for the tip Peter, the burner seems very economical, I have used it many times as an open air burner for spot heats on various things and have yet to get to the end of the first barbecue tank of propane so I'll watch out for the freezing.
G2, it would be very hard for me to estimate how long it took me to make. I've been working on it for months, an hour here, an hour there. I generally work quite a bit of overtime and have a young family so I try not to totally immerse myself in this stuff every spare minute I have, though who knows how much cumulative time I've spent on these forums!
General specs: Made from a freon tank with two 1" layers of 2700 degrees kaowool coated with ITC-100, which is a ceramic heat blocker that acts as an extra inch of insulation. The burner is a venturi design made from off the shelf plumbing parts and works amazingly efficiently.
It seems to heat up to forging temp in 5 minutes or so and heated the last four inches of 1/2" rod to forging temperature in nothing flat at around 2 or 3 p.s.i. With luck it will forge weld at around 5 or 6 p.s.i. Oh, don't use a barbecue regulator, get a good red top regulator rated at 0-15 or so.
Guy Thomas/Thomas Knives
