Austin, i used lava rocks to spread the heat on the hoizontal batch box rocket barbie. I think i need several layers for it to spread the heat.
http://donkey32.proboards.com/thread/799/barbie-core-horiz
If the pics don't show, click on the blue link next to the little crosses.
The batch box is too large for the heat riser. And it smokes a lot before getting to temps. Works wonderfully as a plancha. As a barbie, not so well i need more lava rocks. I haven't tried the
oven yet. Well, sort of. I tried boiling
water on top, but it didn't even remove the paint, and water was just simmering. Too much radiating surface into that barrel cutoff.