I'm building my first gas forge right now. I'm using firebricks and refractory cement(left over from redoing my oil fired boiler) with a steel angle iron frame(so that I'll be able to move it). I redid my math on the volume, and it came out to 248.625 cubic inches. Originally I somehow originally had come up with about 300, and I'm thinking I miss measured originally. The burned is getting mounted straight into the top and will be sealed around it's opening.
I did build a tee burner following the directions in the sticky at the top. Thank you Frosty for the nice clear write up, it was very easy to follow. The only changes I made to them was that I tapped the 1x1x3/4 tee for the threads on the flare instead of the pipe thread and used the pipe thread for a ball valve, as well as using a ball peen hammer to make my flare(one going inside and hitting it with another). For a regulator, I'm using one of my spares for my oxy/propane scrapping kit. Got it tuned to burn nicely(all the way from about 2 PSI all the way up to around 20 PSI) in open air.
Am I going to have too much burner for this size forge, or will I be okay with the 3/4 one that I have now(I think that I had read that the 3/4 ones were good for about 300 to 350 cubic inches)?
Also, on a single burner forge, is an idle circuit worth doing? I'm already contemplating making a bracket for the control valve to hold it to the side, and it doesn't seem like it would be hard to add a needle valve and associated fittings to give it an idle.