Orion Kindel

Gotcha, thank you Maxwell!
Couple more questions, I'm going to line the burner openings in the chamber with refractory as well, does the thickness there matter much?
And would it behoove me to shape the castable there into a ~12° flare for the burners?

Hey folks, long time lurker first time poster. I'm about halfway into a propane tank forge build with a pair of 3/4" Frosty T burners and have been perusing IFI mindlessly for the last couple weeks absorbing all the information I can.

I'm planning on following Wayne build guide, which is essentially a 20# propane tank forge with the flat bottomed chamber. The entire tank is cut lengthwise following a line drawn across the opening of the collar, which is roughly 1/3 from the bottom of the 7" dia collar circle.

For the bottom "half," he advises to use 2 x 1" layer of ceramic wool then (from what I can tell) filled and screed with castable refractory which from rough guesstimations would be about 1-2" of solid refractory. Wouldn't the forge get to heat faster if I filled the void with more wool, rather than an inch of solid refractory, and instead shoot for the surface be around 1/4" of castable?

And for the top "half" he builds his forges with 1 layer of wool topped with 2 full 5lb bags of castable, which to my uninitiated mind seems like a lot more than 1/4", which seems to be the target thickness of castable from other threads here on IFI.

Should I shoot for a thinner castable layer on both halves for efficiency's sake?