A number of years ago ( 25 plus ) I made and welded togather a large swing set for my kids. I used 1 & 1/4 inch galvanized pipe. The project turned out sweet, however I was sick for ten days after the fact. I even went to the doctor & when I told him what I had done he said the stuff would just have to work out of my system. I would get up in the morning and feel fine and about mid morning I would start running a fever and got that serious run down feeling for the rest of the day. I have a lot of respect when welding galvanized stuff.
