Welding issue/question....

admin

I have a Sears 110v MIG welder that I use on small automotive stuff -- making brackets, exhaust tubes, etc.   Works for that.I have a fireplace grate made of 1" square stainless steel bars.  The bars are tack welded together and those welds are starting to fail under the heat of the fire.    I tried using my little MIG on it, and it kind of worked, but I had a very hard time getting any penetration and the (ss) welding wire had a tendency to bounce off the metal and spin around the floor in little balls of molten fun.  I cranked the amps as high as the 110v machine would go, and used shielding gas intended for ss.So...any suggestions for getting a decent weld with this welder?  Would it help if I heated the bar up with a torch before trying to weld it?
Reply:Maybe. That little machine really doesn't have the balls to do great welds on thicker material, but you may get enough of an extra "boost" by heating the material up so it doesn't suck out as much heat when you go to weld it.If the heat of the fire has started to break down the stainless so the welds are failing, I'm wondering about the prep you did to try and weld this. If the stainless is "burned" or oxidized by the fire, you aren't going to be able to make great welds even by warming up the material. You really don't have the power to blast thru that top layer of scale wit a machine that small. You'll need to grind down to good stainless to have any chance of getting this to work. I've done some SS mig and what you are describing doesn't sound like the way SS normally welds with decent material. It wouldn't at all surprise me that the poor surface material is causing you issues..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Not answering your question but after screwing around with several welded grates I finally just bought a cast iron one and all those problems were solved.