1. I have a 99% nickel rod coated with flux. According the MSDS the flux contains barium carbonate, which I believe is used as rat posion. Being a possible contact surface for food, does the flux become part of the weld? Can it be washed away?
2. When welding cast Iron with TIG, the weld puddle sometimes pulses or bubbles at certain place. What causes this? How do I prevent it?
3. Based on Metallurgy why did the technique below led to failure?
Oxy-acetylene torch oxidizing flame attempt to decarburize while brushing with stainless steel. Stacked refractory bricks, to make a temporary oven. Cleaned joint with solvent. Preheated with large propane torch of more than 500 F (temp. crayon), but less than 1414 F (Curie point, checked with magnet). Welded using tig DC - 130 amps (full pedal) ER70S-2 .035" cracked grind out (decarburize) and tried ER70S-7 .035" DC- 100 amps (1/2 pedal) (cracked). Post heated with torch is both cracks.
Best Regards,
Adam Prince