The burner is cast and cured. The crayons drill out easily after waiting a few days to take the wooden frame off. A tip for future attempts: oil or WD-40 the inside of the wooden form to allow for an easy release. The bottom piece of wood with the crayons stuck in should be very carefully sawed off with a hacksaw blade. Emmerling's directions say to "wack it on the edge of a table", or something similar, and by follow these direction unfortunately meant I had to perform the entire casting twice.
The forge shell was then assembled with legs to bring it up off the ground, and the burner port hole was cut out with a cut-off wheel on an angle grinder. Sides were cut out and welded on and were made from 2" x 1/8" material. The directions called for 1/4" stock and I think this would have been preferable, but I didn't have any on hand so I figured the slightly smaller stuff would do (plus it will lighter in the end).
I created some super weird front and back baffle/support systems to hold the insulating firebricks that will act as doors. This was an awkward and tedious process and ultimately I feel there is a much better way. The material I used was 16 gauge sheet steel and I feel it is way to thin. My fear is that intense heat from the exhaust holes will rise and at best warp the thin steel, trapping the bricks. The worse case scenario might be that the sheet steel reaches an incandescent temperature and degrades/bends/warps/melts? rather quickly. But, it's an experiment, right! We shall see.
Finally, the pieces are together and the metalwork is more or less finish (I realized later I forgot to add a handle...woops). I added the two layers of ceramic blanket to the interior and rigidized it with coloidal silica with additive food-coloring so that I can tell where it has been applies. I don't have photos of the process of putting in the ceramic wool, but I can say I am glad that I didn't make my primary round hole any smaller or else the rolled up piece of wool would not have fit in at all! I fire cured the rigidizer to get any remaining water out and then began the casting.
This was a tricky step but very satisfying to shape it into an aesthetically pleasing and hopefully functioning interior. The material used was Kast-O-Lite 30, a high temperature, insulating, castable refractory. The final picture shows the forge on its side as it sets up.
So far so good. Soon we will see if this burner actually functions as planned. Next up some proper plumbing, curing, and Plistix application. Stay tuned!
Starting the process of building a propane tank gas forge except I'm going with a burner design called a ribbon burner. Here are the initial steps of building the burner. The starting material is a piece of 3" x 3" x 1/8" square tubing. The front in cut out, a hole in the back in cut out and a baffle for the propane to filter into the plenum (chamber behind the to-be castable refractory) evenly. The sides are welded shut- carefully now, no leaks allowed here. Then the burner is ready for a 2" pipe nipple to be welded onto the circular hole and then the casting can begin. A link for these burner plans will be on my links page.