ive done some welded maille, more butted maille than you could shake a crane at.. welded maille is part of how i got into bs in the first place. what i did was take an insulated firebrick and hollow it out and put a hole in the side. then i took a mapp torch and pointed it into the hole on the side. use a really heavy duty (prefferably cheap) set of needle nose pliers and use those as your tongs, pick up ring stick it in the "forge" get it a good orange color. dip into borax, put back into heat until it gets that butter look to it pull it out hold it where just the overlap is on the piece of plate (what i had at the time) and wack it with the hammer. drop into a bucket of water, 90% weld success rate on them, making the 5-lets was a little harder but once you got the hang of it it went pretty fast. helps if you preheat your plate because it will suck the heat outa the little rings really fast!
i used bailing wire, close as you can buy to wrough iron wire. i tumbled the rings between initial welding and assembly to get rid of flux residue, made 1 shirt... it paid for my junker 4x4 lol