gas forge for welding in Tools and Tool Making Posted March 27, 2008 Thanks, Steven. Nice design, but I'm already pretty well committed to ceramic wool (with a hotface) for the lining. (I already have the wool. ) What sort of burner are you using? Naturally aspirated, or forced air? If it's natural, is it a Reil or something else? And what size orifice are you using? 0.030" MIG tip? Or did you drill one yourself?