I am welding together a roll cage, its made out of 2" OD 1026 DOM. We used 7018 to tack the tubes together while it was in the truck, now I am using the TIG to finish welding it.
I think using the 7018 to tack was a mistake as whenever I get near the
7018 tacks the puddle goes sour and starts bubbling. Repeated grinding out and rewelding is not helping much, although I did figure out if I go to more heat and a larger filler rod and I focus on the rod in the beginning then let the droplet flow into the ground out groove I can mitigate the contamination a bit.Anyone care to comment on this? am I correct in thinking the 7018 tacks were a bad idea? Any other tips for eliminating contamination without totally butchering the weld area with the grinder?
Would adding in a root-pass in the ground out areas with Silicon-bronze be a totally bad idea? I know in the "Old Days" they used to braze cages together, and I have had good luck with silicon bronze on dirty old sheet metal, but I dont know how it would do in a structural application...
Thanks for any advice...
-Zach