In the last post the plan was to line the forge with 2 layers of blanket and then cast an interior liner. In order to do that I needed to make a form for the inside cavity.
Once that was completed I calculated that I needed 36 inches off the 300″ long 24″ wide roll to make 2 layers in the forge. Which means I have plenty left for future projects. With the blanket in I secured the form and mixed up the casting refractory. Since I didn’t have a reasonable scale to measure I decided to err on the side of too dry rather than too wet, based on my experience with other casting media and based on my understanding of the product. It is kind of odd stuff, sort of like styrofoam beads in cement with fibers. The mix I wound up with was a “pack-able” consistency and not really pour-able. This was expected and I knew there was the risk of having some voids in the lower end especially around the burner inlet port. Reality did not disappoint in this.
Which meant that after initial curing (24 hours) I needed to patch some areas. Which went quite well.
While the forge was curing post patching it was time to fire up the lathe and start making burner parts.
First up was to turn the 3/4 to 3/8 bell reducer which is the burner end cap. This makes it smoother and will allow the burner to perform better.
Once that was turned i moved to the jet injector tube. There are multiple ways to make this pice. One method is to take a Schedule 80 1/4 inch steel pipe and thread it with 1/4-24NF threads and screw in a mig torch tip. This is supposed to work well but I really didn’t like the level of thread engagement. It just was too sloppy and easily stripped out the copper threads on the mig tip. Being the perfectionist that I am and having a lathe I decided to drill out the end of the steel pipe and turn a brass adapter, solder that to the steel and then tap tighter threads in the brass. Here is the result.
Next up more burner parts and applying the ITC-100 to the forge body and heat curing all the refractory.