Gonna attempt some welding when the weather perks up a bit?

I was mooching around for something in my den earlier on and came across some fire resistant plate,this plate looks looks like asbestos but its not,its used to seal off the inside of the chimney around the flue.

Was thinking about making a jig to protect the shroud of the mig welder fom hitting the sides of the metal box section where I'm welding a joint,the jig will attach to the square box section about 3/8" to an 1" up from the welding area maybe.

I don't think I can watch the shroud and keep an eye on the weld at the same time? so do ya reckon this jig might work for stopping the contact with the metal and at the same time its fire resistant material ie it should take the heat from the arc?