I'm working with 1/4" mild steel plates and 2" square tubing which is also 1/4" thick. I'm currently using a 115 volt arc welder with 3/32" E6011 electrodes. It is taking for ever and requires several passes to achieve a nice strong weld pattern. I do have a 240 volt Miller arc welder that I can use instead of the 115 volt arc welder. What size electrode would be good to use with the 240 volt arc welder? Thanks for your support.