Brian
I have Magnesium welding rod alloy AZ61A I have used to weld magnesium motorcycle racing wheels that have been damaged and it work very well. It is similar to welding aluminum I used the same 100% argon flow 10 to 12 LPM AC balance from 30% to 45% AC Frequency was from 120hz and up to 200hz on my 250EX. Yes you have to get the welding surface clean and the rod clean, the rods oxidize very easily sitting around they turn black. When welding magnesium the weld has a different color to it then when welding aluminum. Now getting the welding rod I had to by the minimum amount and that was about 50 rods they are light you get a lot per pound. It probably cost more for me to send you some rods then it will cost for you to buy them Canada / USA boarder line. Question are the screeds electric or air ones and can you take off the vibrators and move them?
Everlast PowerTig 325EXT (Canada)
Everlast Power I Mig 250 (Canada)
Everlast PowerPlasma 80S (Canada)
Everlast PowerCool W300 (Canada)
Everlast PowerMTS 250S Fitted with a 30A Spoolgun(Canada)
Miller Dynasty 400 wireless(Canada)
Millermatic 252 plus 30A Spoolgun(Canada)