[Andrew Rowe]

Lynn, use mild steel solid core 0.9mm wire with CO2 shielding. This is the most cost effective and best results with no cracking. It will weld any of the armour from any country, and yes use techniques that dissipate the heat from the weld zone, as David has eluded to. One technique is "backstep" welding, where you stop your run from where you last started it , if that makes sense, as it does not allowe heat to keep transferring along the direction of weld. Also use veeing the steel as well for penetration, and gap depending on thickness for sound welds, Cheers Andrew.