That burner is a good start but most of the heat just goes around the the pot. I have three pots, 60, 80 and 100#s and it took much longer than the old plumber's pot I have but alas it can no longer be filled anywhere due to no OPD device.
So I made a shield and lid to turn the 100,000 BTU burner into an oven and made a holder to heat the 10# cast iron pouring caldron to fill a commercial ignot maker that came out of a linotype shop. The lid on the oven has a threaded rod to pick it up and can be removed for storage.
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