Root runs in Weld to Code

I’m currently learning Weld to Code using MMA (1554), part of which involves a butt weld of 10mm steel plate. While I have no trouble with the hot pass and capping runs, the root run is proving difficult to master. The two plates are bevelled at 45 degrees, gap is approx 1.5 – 2.0 mm with 2mm face, using TC16s at 100 amps (Unimig 200), inductance midway.

Results range from


[LIST][*]a good 45mm continuous bead length with 2mm ridge through the root before burn through, stop & start again[*]complete 150mm continuous bead (length of plate), perfectly even but short of the root by

Root runs in Weld to Code