Can a large magnet screw up a mig weld???

Ok... I am trying to teach myself to mig weld... (with the help of the internet.

I got pretty decent at laying down a bead on a cleaned up area of an old test fender...
Then I started practicing filling in holes with the use of a homade copper back plate...

Getting decent at both...

Yesterday I decided to weld a patch to fill a 2" x 3" hole...
I cut a patch out of sheet metal I picked up at Home Depot (22 gauge I think) Had a pretty good fit and stuck a big magnet to the back of the fender to hold the patch in place.

When I went to weld it, I couldnt get the welder to lay a bead. Just spit and sputtered like crazy!! I upped the voltage, played with wire speed, moved the ground around. NO GOOD!

move back to the other area of the fender and could lay a bead...

Last night I got to thinking, could it be the big magnet???

 

I've used magnets before without problems..

Curious as to what type of metal you got at HD?

 

For sure, welding near a magnet will screw it up something fierce and the bigger the magnet the worse it fucks up, same with a tig.

weld as far away from the magnet as you can, then reposition magnet and go again.

 

Magnetism will affect a welder, I used to work in an aluminum smelter and there was a HUGE magnetic field in there. We had to weld pipe under the cell line and the magnetism would do really weird things like pull your weld away from the stick, drag your puddle sideway, strange stuff.

 

You bet ....welding in a magnetic field is like pissing in the wind... everywhere but where you want it....you have to get away from the field to get back to normal

 

I have used magnets to hold patches in place and haven't had that problem. What kind of metal is the patch piece.

 

I think a big magnet will dick up your welds. try a small one, tack it , then remove the magnet

 

Yes....this is true.......use your magnet to get your weldment fitted together and then get the magnet outta there before final welding.

Same goes for magnetism too, find a pipe that you just can't get to take a weld, look for magnetism as a possible problem. Carl Hagan

 

I've run into that with a TIG weld before. The closer I get to the magnet, the worse the arc blow. I would think the MIG would be less affected by it but take off the magnet and see what happens. If you still have issues maybe your shielding gas isn't flowing right? kink in the torch lead?

 

This is really one of the very 1st things you learn when taking a course, certifying, or just any all around formal instruction. Carl

 

Make sure there is no coating on the steel. like galvy

 

Who needs all that crap when I got you fellas!!! lol!

Seriously, I wish I had time to go take a welding class!!!
Thanks everyone!!!!

If anyone in the fort worth area wants to make a little cash on a saturday giving me some instruction, PM ME!!

 

The magnet will screw up your weld. Use the magnet to hold the material in place enough to get a couple to tacks on it, then take the magnet off and finish up your weld.

 

Not only will the magnetic field affect your arc, the heat from the weld can ruin your magnet.

 

It's seldom you'll get everyone to agree on a subject. Yes, magnets will mess with your mind when your welding near them. I use my gas torch to tack weld first when necessary.

 

An easy way to get around the magnet is to just tack your patch in the middle to where your wire sticks to the patch, then let out a little wire and cut it off at the gun. That way you have a "handle", to hold your patch in place, and of course wear your dry leather gloves. Works really well on smaller hole filling where your fingers and gloves get it the way...........

 

Yup, and the bigger the magnet, the worse it is. I was working near an aluminum extrusion (roller coaster magnetic brake) that had some of those crazy strong finger-breaking magnets embedded it in. I could not get a decent bead within a foot of the magnets. I ended up having to dismantle it and move the magnets away to finish the job.

 

Thanks!!!
I wonder if it will still be magnatized when I take the magnet off.....

 

Not likely, in fact pretty much "no" period

 

Cool deal, I had that happen to me. I never asked about it just knew that welding was good without the magnet. Love this learn me how stuff.

 

Ive had the arc try to travel towards the magnet, but can usually get a decent tack so I can remove the magnet. Im wondering if you got a piece of galvanized sheetmetal for your patch? Galvi makes the weld spit and sputter and also gives off a gas (a form of cyanide I believe) which you dont want to breath. If the arc looks green and gives off a white cloud, you have a piece of galvanized.

 

i try to use magnets as little as possiable due to issues that cam occur

 

ok so a magnet will mess up a mig weld I have used them and had the same problems so when I need to weld a small patch in I take masking tape and put it on one end of the patch place a small tack weld on the other then peel off the tape and weld the patch up. I have even done this with 1/4 inch holes in panels using a plug in the hole. If you are too close to the tape it will catch fire but you can easy blow it out. hope ;this helps RED

 

turn the gas on?

 

GATOR...you said BIG MAGNET so don't even try and tack weld. the magnetic flux will screw the ark up BIG TIME...POP.

 

Was the metal galvanized? If so there is your problem.

 

Oh, so that was you watching me that time! (okay, actually more than once...)

 

Where the hell were all you guys when I tried to tell this guy that magnetic welding clamps were a bad idea and he was telling me I was full of crap? See page 3 of this post..
http://www.jalopyjournal.com/forum/showthread.php?t=381013

 

Kind of unrelated...

Magnetism is the main reason to have an AC option on your stick welder. When welding on magnetized pipe fences, I have to run AC just to be able to control the arc. Non magnetized pipe, I run DC. The AC negates the arc blow.

Allengator, if you want to drive west 30 miles to Springtown to my shop on Saturday, I can show you the basics on Mig welding. I have two Migs and am pretty proficient at using them.

 

Somewhat related side note. If you ever weld galvy and breath some of the yellow acrid smoke you may become physically ill, especially the shakes. If this happens drink a glass of milk, instant relief.