I've read Richard Finch's book on welding, and actually have been welding for many years, but one thing still gives me a problem. When I TIG weld mild steel, my welds sort of "foam up." I'm using argon as the sheilding gas, and I've tried increasing the flow, larger and smaller cups on the TIG torch, and using both thoriated and non-thoriated electrodes. I use high-quality certified welding rods. I've tried welding slower to keep the argon over the weld longer, but no luck. This happens mostly when I'm welding thick 1/4 inch material. Everything is clean. No drafts to blow the argon off he weld. Tried both DC electrode negative, positive and AC.
What am I doing wrong?
Thanks for all. You can even flame me if you like. I like it.