JMForge

sorry about that i should've made it clearer. Yes I'm talking about the top plate where ill be putting coal and holding the rotor. I'm planning on using 1 1/2 inch black pipe with a t section to create my tuyere and a pvc ball valve to control my air flow as ill be using a single speed bathroom vent fan as my bellows.

I'm wanting to build a forge from a brake rotor forge and sheet metal, I'm trying to understand what gauge of sheet metal I should use.