Step 4: Adding refractory
Of course, to keep the forge body cool enough so it is not damaged, we need a layer in between the fire and the grill. I will use Mt Savage refractory cement, although you may use 1 of the following recipies, a 1 part furnace cement and 4 part perlite or 50/50 of sand and clay. We will want to fill the forge right to the tuyere and have a 70 degree angle upwards to provide a trough to hold our fuel and blade. Let dry.