Step 4: Finishing touches
Over time, the bricks will crack. As long as they are fastened securely and don't come apart, there is no effect on the forge's performance. I used two of the thinner bricks on top and bottom to improve the insulation. Use STEEL wire to fasten them together. Use 8 or so ties across the width, and at least two across the length. If desired, add a handle.
The last steps are optional, but recommend for safety. Make a simple stand to keep the torch upright. This reduces the fire hazard if you happen to bump the torch out of position during usage. Next, cover the rubber propane hose with a piece of pipe or conduit so that if hot material flies from the forge and lands on the hose, it will not burn your shop down.