Details (even extraneous) are much appreciated, that's why I asked here.
I have the base from a forge I made years ago. The top was intended to unbolt and be raised up on firebrick as needed; the sides didn't seal well, leaked the hot stuff. The base has legs and end shelves (firebrick doors), might as well use it.
The body will be a bit more than half a cylinder; I like to go past half on the cylinder to gain some height without a lot of loss in width. 13" diameter, 16" long. A friend has a roller, I've already got the 16 gauge. I'm still thinking on the size, if I really want it that large.
Two layers of 1" 2600F wool, spray with rigidizer and dry. Kasto-lite 30 over the wool. I like 1/4-3/8" to keep the thermal mass down. All stuff I have on hand, which is nice. I lay a floor of insulating brick and then put 1/2" or so of Kasto-lite over the top. I haven't done any welding for a long time; if I did, I'd get some kiln shelf to protect the floor.
My forging slowed down a lot 10 years ago, when we moved into a 90% complete house. I made large strap hinges for the saloon doors on the shop and barn, then many other tasks took over. I was laid off in 2015--more time, right? except hard to focus on anything except finding work. I found work 2018 in Seattle for 2 years, Massachusetts for 1 year and as of April, I'm retired! I am greatly enjoying being retired.
Steve