[eddy8men]

i replaced quite a few patches on my T16 floor using normal mild steel plate and .8mm mig wire. i welded it normally in one run and had no problems.
the only time i got cracking of welds was doing short 1" welds on the 1/2" wading plates. it goes against what everyone else has said but i put it down to not enough heat transfer from the weld to the armour plate. i did a few large plate patches on the side armour with the mig turned up all the way and had no issues as i believe the original armour got hot and took longer to cool down helping to even things out.