Grant, I agree that theres a coating there, I'm not sure its always galvanizing though. I suspect its similar though and reacts similarly. I've gotten in the habit of cleaning 1/4" around the sheet metal I'm using when I weld. I like leaving most of the stuff on, it doesn't burn off too bad other than right where I'm welding and it doesn't seem to rust. My next step is to buy a bigger grinder. I'm going to get a 5" with the thinner grip. I don't know what its called other than its not the paddle grip my 4 1/2" Makita has, that one makes my hands tired quick. -Curt From: G Mann via Mercedes <firstname.lastname@example.org> To: Mercedes Discussion List <email@example.com> Cc: G Mann <g2ma...@gmail.com> Sent: Friday, June 5, 2015 6:42 PM Subject: Re: [MBZ] Slag hurts PC boxes are most likely clad with galvanize material. Galvanizing requires the base metal be coated with Zinc compounds which can and WILL contaminate your weld, thus welds that look like bird droppings. The job of rod flux is to carry away the contaminates in the weld puddle, but the flux core wire from China doesn't have enough volume of flux to combat zinc contamination of the weld puddle.. in fact.. if you were using gas, you would have to crank up the flow rate to over come it.
The fact that you are having splatter and slag issues should have keyed me to tell you the zinc boiling off is likely the cause. I overlooked that.. my apology. Try a welding a piece of the same material you have dressed with a grinding wheel to clean steel.. see if it doesn't give you a much better weld. I will lay bets it does. Go to your local steel supplier and pick up some end cut scraps for practice, in MILD STEEL only.. then run a few passes.. look at the difference.. you should see immediate good results.. even with crappy Chinese flux wire from Harbor Fright. A good part of welding is knowing the metalurgy of the metal you are joining.. and how it affects the weld. _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com