I have been welding structural for a decade now. I have always been told and readily believed other welders and inspectors saying you have to grind it off. Today I pretty much told my foreman he was a joke and texted the owner saying i was not the guy for the job of welding through galvanizing, he believed me, so I won and got to watch the foreman grind my parts, HAHA. Well I get home and start googling and come to find out I was really wrong.
Zinc is NOT toxic, it will make you feel like crap for a couple of days until it leaves your system (I was also told many times that it accumulates, so every time you are exposed it takes less time to make you feel icky)
You CAN weld through it without compromising weld integrity as long as bead appearance is not affected.
I will man up tomorrow and admit I was wrong. But He is still a joke regardless.

How do you guys handle galvanizing? I have read use a low silicon rod, any suggestions? I have always used 7018, which I know is low hydrogen.