So I picked up a little mig welder. My beginners welder if you will.. I set it up to practice on a fender laying on the table. Hooked up the ground to the fender and when I went to weld I got a huge spark off of the ground clamp...wtf? I figured before I went any further I would check in with the experts..Anyone? I cant imagine this is normal

Did you assemble the machine? Leads hooked up to wrong polarity?

Normal if the ground contact is dirty or not attached properly to the "work"

It was hooked up when I bought it

Thank you! This is probably the cause..will update now that I know my lifes not in danger

If cleaning the ground to bear metal doesn't work, try to get a copy of the manual for the unit and verify that it is wired correctly. The polarity is reversed based on whether you're doing Flux-core welding or true MIG (using a gas source). Sometime there will be a diagram on the unit itself to outline how it's supposed to be setup.

I would go with the ground clamp first and then check the terminal inside the welder. Then check the gun supply terminals.

Reversed polarity shouldnt make it pop. I reverse the polarity with MIG all the time when welding upside down to keep my ear wax virgin.

When welding make sure you have the proper stickout so the wire doesnt burn back and stick to the tip. Make sure you are not shorting the tip out on the material.

Easy test to see if the board has a short or blown diode. Run about 5 inches of wire out and then touch the wire to the material and press the trigger. You should see the wire pre-heat and glow red if everything is ok.

If your spool is old it can get rust deposits on the wire surface. It will sputter and pop.

A mig will weld on rusty metal - very badly. When the arc hits the rust you will get sparks all over, your puddle will fly around and you will be too dazzled to see what you are doing. Then when it cools the bead will be just sort of glued to rust.

So the important thing is to make sure that the ground and the weld surface are shiny new steel. That often means cutting back to clean metal making for a bigger repair. Do that - it will be worth it. Also the heat and wire feed adjustments both do things to the weld so you will need to experiment. Bigger metal needs more heat, so if you are welding something thin to something thick, always start heating the thick piece first. You may never have to directly heat the thin, the puddle will just melt into place.

Good luck.

Thanks everyone!