Hoping to get some help improving/optimizing my JABOD. I built a box following Charles' method and today was my first good long day with it. I wasn't able to get a good heat on top of the fire I had to slightly bury the stock which at one point got it up to welding temps when I left it in a bit too long. Is that normal, or do I need to make some changes to my firepot? I also got some bitluminous smithing coal for the first time so I'm probably introducing some inefficiency there too. For instance I was adding the green coal on top of the fire instead of letting it coke up around the edges first. Did some searching here afterward and realized my mistake.
My firepot is 4 inches wide, 9 inches long, and 5 inches deep. The center of the tuyere(3/4" schedule 40) is 3 inches down from the top of the box leaving about 2 inches below. I have 2 pieces of hard firebrick standing the long way on top of the forge as a back stop. Should I make the firepot a little shallower? Deeper? I eventually would like to form the firepot out of fire clay once I learn the best configuration.