Having trouble tig welding horseshoes. I'm using a AHP 200x AC/DC tig welder set at 160 amps. Can't get good welds. Using 1/16 filler and 1/16 green tungsten. I cut one horseshoe in half then weld it to the front of another horseshoe. Horseshoes are brand new and are 1/4" thick. Mill scale is removed and cleaned with acitone. It's hard to get a good puddle. If I up the amps I get black soot and multiple craters. Any suggestions would be appreciated. Thank you.