armour plate welding

[rob love]

Welding on armour plate calls for exactly what Chris just mentioned; preheating the work. Especially if you find that it is cracking after the weld.
I treat the armour plate like I would treat cast metal. Cast calls for the metal to be warmed up to 400 degrees before welding.
I used mig on some of the front armour repair on my UCmk1, and the only real problem after dressing the welds is that the welded area ended up looking nicer than the rest of the armour plate. Nothing a couple of strikes with the chisel won't fix, mind you.