Don't quote me, but I think you need a gas welder, but you can also use a tig welder. Not sure
http://www.weldingtipsandtricks.com/welding-4130.html
They are welding 4130 chromoly with a tig, but idk. Just google it....
check the dates? WTF? SO the way I read that I drill the hole, then drill a hole the size of the nut head halfway in so the bolt sits flush? What if I fuck up my deck?