Had to weld the burner holder in place… Used some sch 80 pipe, then drilled and tapped three 1/2-13 holes located approx. 120 degrees apart…
Next I built the forms. 10″ diameter concrete tube form from Home Depot. 19″ piece, split down each side. I used some 1/4″ plywood ($5 for a 1/2 sheet at Home Depot), and cut 6″ wide X 24″ (just because it was that size) pieces to fill in the rest of the form.
I used duct tape to put the form together… hopefully that will make it easier to get the forms out once the castable cures enough.
I also picked up a 2″, sch 40 PVC conduit, 90 degree. I had to heat and form it to get the radius I needed. But the idea was/is to form a channel in the castable that will “guide” the burner flame around the inside. After getting the dent I needed, I sawed the PVC with a taper around the curve that terminates about mid way on the opposite side of the forge from where the burner enters.
I also used the 1/4″ plywood to fill the front and back “doors”, trying to ensure that castable would cover most of the steel portions of the doors… again… used duct tape to keep things in place.
Since I had a limited supply of castable, I decided to do a “hybrid” forge… used 1″ of #8 density Kawool next to the shell, and used the castable for everything inward from there.
5 bags of Mizzou 3000F castable later…
Now to leave it alone for at least 2 weeks… then try to take the forms out. After that I suspect it will be a month or so before it will be cured enough for some firings.
NOTE: YOU MUST LET CASTABLE REFRACTORY CURE NATURALLY! IF YOU TRY TO RUSH THE PROCESS BY FIRING THE FORGE, YOU WILL SERIOUSLY DEGRADE THE LIFESPAN OF THE REFRACTORY, AND, IN SOME CASES, IF YOU GET TOO OVER ZEALOUS, HAVE TO TEAR IT ALL OUT AND START AGAIN!!!!!