I was fooling around with a larger forge a while back which did work well, but I needed to use a different set up.
I had this one Isolite fire brick here, so I thought I'd make a one brick forge
Attachment 9709 Attachment 9710
I wired the brick together, as they usually do crack in use, I also built a frame around it just to make it easier to keep in one piece.
Here is it with the torch fired up
Here it is after one minute
No I insert a piece of steel in there
....and after two minutes or so, I have a nice cherry red piece of steel to work.
I can use this to heat up steel to bend it, or even to shape it with a hammer.
The block cost about $6 here, I had the torch and the wire etc, so the cost is minimal.