I have a lincohln pro-mig 140 that i am using for my project and i am currently welding a bunch of spot welds up. My problem is that sometimes when i'm welding it will stop crackling and make more of just a hissing noise. It will still weld a puddle but sometimes it doesnt seem like its welding to the other metal, just the wire is melting, and also it seems to run cooler causing big mounds of metal instead of flattening out. I've tried switching the ground around and also switching the tip along with straightening the line. still no dice. Any help would be appreciated. I really want to continue on with my project but this is too annoying. Also there is usually a ball of metal at the end of the wire after i weld if that matters.

 

It's probably how far away your gun is from the welding surface.

If it starts to ball up and make a hissing sound try bringing the gun farther away from what you're welding. Either that or turn your wire speed up or heat down.

 

I'm having the same problem. I had my welder setup for flux-core 035 wire, and I switched to 308L 030 wire. I can't seem to get the settings dialed in. Its either burning the wire before it hits the base metal, or it isn't penetrating at all, and just mounding up. I hadn't tried moving farther away, I'll give that a shot. I had moved the wire speed all around, turning the heat up, down, etc. Nothing seems to help much.

 

replace tips, and nozzles, and keep the nozzle clean, this helps alittle with this problem. then its just normally add more wire speed.

 

when i first started welding i had this problem ,i still do sometimes ,just like its been said turn the wire speed up ,i dont see why cleaning the nozzle is going to do anything unless he is useing argon ,could you tell me why this will help please

i think you have the gun to far away ,maybe try welding in the center and moving out into a circle would help

 

Ckeck your wire feed rollers. If they are worn so much that they have a U shaped groove instead of a V shaped one it will cause the wire to bunch back and recoil back into the liner. It's the biggest pain in the *** on spot welds because the filler just sort of splatters on top of the basemetal. You can tell when it's doing this when there is a jagged line around the edge of the tack weld. It kind of looks like what happens to silver solder when it drips and falls onto the table if that makes any sense.

In the mean time try cutting your wire at an angle with a pair of wire cutters so that it has a sharp point on the end and hold a shorter stick out when you are tack welding. It will help you get a lot more consistant, hotter start.

You might also want to make sure that the liner hasnt gotten loose from the setscrew in the diffuser and retreated into the gun a bit. The wire can arc off the inside of part of the setscrew if this happens.

 

Thanks for the info guys. I already tried keeping the tip further or closer. Its weird because in some spots it acts up like that but then i move to a different spot of the car and it works fine...