srthyuj
Wait, so you mean to tell me that these pipes that were rusted on the inside like hell, and was painted afterwards, and which I grinded until they were shiny still had a zinc layer?
When grinding galvanized materials, you initially take the surface off and expose a bright shiny layer of zinc.
If you grind further you remove the zinc and expose a slightly darker (comparatively blue-er) steel surface.
Because zinc boils at a temperature lower than steel melts any zinc you don't remove in the area that gets hot boils off leaving white, yellow and black residues, and in extreme cases whisky wool like structures.
Inhaling zinc fumes will initially give you an awful taste in your mouth, and if you inhale enough will cause a very unpleasant flu like illness lasting several days.
Whilst there are practical reasons why you might occasionally need to MIG or Arc weld galvanized materials, it's not something anyone would ever normally want to TIG weld, especially as TIG really depends on extreme cleanliness to give strong welds.
Yellow soot is from the zinc
Wait, so you mean to tell me that these pipes that were rusted on the inside like hell, and was painted afterwards, and which I grinded until they were shiny still had a zinc layer?