I am sorry if I offended. That was not my intent. I would have to know captn would open his pie hole. I dont think he can help himself. yea look at me lol.

Your right about contaminating your tungsten. I dont think your gona get anough of a wiff of zinc oxide to hurt ya. This sounds like a wifes tale but it does work. If your worried about getting sick after getting a good blast of zinc oxide then drink some milk and it helps prevent you from getting sick. I dont know how this works I just know from expereince that it does work.

As far as identifying stainles it is gona be non magnetic. not always though there are some grades of stainless that are magnetic but he magnatism is gona be a bit weaker than for steel. you can also tell by grinding on a small portion of it to see what the sparks are like. I really dout they would be stainless as they want to build as cheap as possible.

As far as not grinding it if it is stainless it is always good practice to clean up the area your gona weld anyhow. you will know its zinc coated as soon as you start grinding. it takes twice the heat to burn through the oxide layer than it does to melt the base metal. also do you really want that junk in your weld? if your tigging or even migging steel definatly clean off the mill scale. clean makes all the difference in the world.

Also you do know your supposed to grind your tungsten with a green wheel right? if you grind it on a wheel you grind regular steel on you will contaminate your tungsten.