the gases released from galvanized steel when welded is very toxic. (not to mention gives off a pretty green glow)If your just doing a few pieces your not going to die from it, probably wont even get sick. I would just recommend getting some plain sheet metal( i know Home depot lumber yards sell small pieces)
I can not warn you enough about welding on the galvanized metal. Galvanize coating is ZINC, it gives off fume what will cause "Zinc fever" as it was called years ago. It is VERY, VERY serious. Eric, known here as Sevt_Chevelle was damaged for life because of welding on a Honda with weld thru primer (also zinc rich) ask him, he is more than happy to explain the dangers.
As Martin said I got Zinc "fever" back in Dec of 98. Since then suffer daily said affects like constant coughing and shortest of breath. Last Dec/Jan I found out that I NOW have a lung diease because of my exposure to Zinc from welding.
To make a long stort short basically the air sacs that make up your lungs, mine are dying off, my lungs are self destructing.
My total lung function is around 45%. If you rated that % out is equals to a male in his late 70's who was a smoker for 50 yrs.
Am 26 yrs old, be 27 on the 22 so this isnt something I got from a lifetime of welding. All it takes is that one time. My lungs are shot because I didnt fully understand the dangers of welding on zinc and didnt protect myself from the fumes.
I take daily and weekly meds. Two inhalers in the morning and night. One cost 35 bucks a month the other is 65-70. Each week I have a infusion with human steriods that help stalbize the lungs. From when I started taking this med back in Jan til now it has cost me around 1500 bucks. This is something that will stay with me for life, it WONT get better only worse. So please use some caution...Eric
Ventalation!!!!! and more ventilation. If you have access to one, I much prefer TIG to MIG for galvanized. I worked on school busses for years and all the panels have to be galvanized. With a TIG, you can boil the zinc off just ahead of the actual weld and the fumes are not so bad.
I wasn't thinking too well and did some stick welding on a couple of seat brackets in a closed garage. Less than a dozen 1" welds and it put me out of comission for a day. NEVER AGAIN.
Thanks Eric...My sincere hopes that you do get better. I have asthma so I understand the inhaler thing. Until I find some plain sheetmetal(more difficult that I imagined) I'll Mig weld Galvanized..but since my patchs are small I'll sand off the galv and still treat it with respect.