What size wire - might try droping the ext cord and see what it does

 

Check the polarity of the machine. Sounds like it may be backward.

 

Thanks, I did check the polarity when I switched from gas to flux...so I got that part right. Wire size is .035

Thanks guys

 

Drop back to 030 wire - works better with that size welder -
find a piece of metal like you are trying to weld on and
see what it does

 

How far away from the metal are you holding the gun?

 

Do you have a good ground. Sounds like you don't have it grounded well.

 

If you're welding on the body wouldn't it work better to use gas and solid wire?
Mike

 

This problem has happened with both gas and flux...

I think its the ground. Difficult to get a good clamp on clean, straight surface in some places. I will try harder to get a good ground, I just wanted to make sure I wasnt missing anything obvious besides the ground....

 

This problem has happened with both gas and flux...

I know you have checked polarity, but have you swapped them for the heck of it just to confirm? Perhaps it was wired backwards?

 

Sounds like you are holding the gun too far?

Have you practiced on regular scrap steel or did you jump right into trying to weld on your car?

Make sure the machine is working right on a more controlled weld.

If ur welding on a car you need to make sure everything is clean especially the ground.

Idk if the magnet would mess with the electrical conduction but you could try getting a thick braid of copper wire and holding it against the panel you are welding via a magnet. (Sandwich it between the car and the magnet so the braid touches the panel). Clamp your ground to the other side of the braid.

 

I think its a combination of both holding too far and not having a good ground.

Time to take a break... pretty frustrated.

Incidentally, I have practiced on a flat piece of steel, so I am thinking that my technique on the flat piece isnt translating to the car...i.e prob not a great weld AND gun gets too far from the metal

 

If doubtful about the ground, try clamping a small piece of flatbar in the ground and weld it in an out of sight place on the body. All it needs is a small tack and it can be broken off when you're finished.
Mike

 

Just another piece of advice from a guy who started with MIG less than 2 years ago, a car isn't going to be the best way to start. I'm sure you bought your machine with auto body in mind but you should at least get a basic technique/form down on various types of joints in a controlled setup. Get some flatbar cut it into strips make some joints. Get a piece of plate and just run beads around and across it. Most guys welding auto body stuff especially at home tend to make a series of 1,000,000 tacks so they don't burn through the metal but there's guys on this forum who can weld razor blades with your machine.

 

i think the problem may be that the wrie speed it way to fast.
on a Lincoln 140 with .035 fluxcore with try the settings at just below 2 on the wire speed and all the way max of the voltage. should work perfect!!!

 

Ok, this I will try next, along with finding a better ground. I know I have the wire speed set fast.

As for gun distance - I don't know what exact #s but I am holding it maybe 1/8 inch away or so.

Thx guys

 

Not that this is your problem, but welding on auto body stuff usually involves welding out of position, usually vertical, or horizontal and occasionally overhead. ( no one seems to replace roof, trunk or hood panels for some reason... :laugh Welding out of position is NOT the same as welding flat. I usually strongly suggest guys who want to do this set up their practice pieces exactly the way they are going to weld. Welding on flat is a great way to learn the basics or gun angle, stick out, travel speed etc with out all the complications welding out of position adds to the mix, but you still need to learn to weld out of position before jumping into a project like this if you want good results. Also I suggest guys set up practice pieces in real world positions after they learn to do out of position welds at the bench. Doing overhead welds are one things, doing them laying on your back with the gun jammed against the floor because you only have 16" to work is another manner entirely. A lot of time you end up laying on the floor to do welds on lower panels unless you have a lift to raise the car to a more comfortable level. Again once you learn the basics and are doing good consistent welds in a comfortable position, it's time to learn to do so under real world conditions.

The other thing I notice is guys don't really spend the time practicing on material similar to what they are going to weld. Learning the basics is easiest on material 14 ga to 1/8" on smaller machines as you don't burn thru as easily. However again, once you are doing nice consistent welds, you need to apply what you learned to thinner sheet before starting your project. Welding thin sheet has a whole new set of requirements, almost perfect fit up being one of the big ones. It's a lot better to go buy 3 or 4 scrap fenders at the junk yard and chop them up and mangle them, then it is to screw up the project car, I've seen plenty of minor repairs turn into major replacements because the project kept getting bigger and bigger as the guy kept screwing things up.


A sanding disk will be your friend. Grinding disks are too aggressive for thin sheet on average. Flap wheels or a rubber backed disk will remove rust/paint better while not removing as much material. You need to not only sand the area you want to weld, but your ground point as well. You need to go thru all the paint and putty and get down to shiny silver metal. Rust won't cut it. I'm not a big fan of magnetic ground clamps, but in some cases like body work, they make good sense, as long as you make sure you get a solid ground. Too many times the ground won't touch the steel well on irregular surfaces and you have to do something to adapt.

 

So did you try it with the wire speed at 2 abd voltage maxed??

 

I will update hopefully tomorrow. Had to go out of town for work....

 

The most common problem I see is a bad miggun with this complaint.
The weld conductor in the Lincoln magnum 100L gun breaks under the boot at the welder end.
You can find it with a volt meter. put a clean piece of metal in the work clamp. run out 1 inch of wire.
clip the meter on the gun power block and the gun diffuser. Try to weld. high voltage = bad gun.
Low to zero is good gun. With you machine set up right, the 035 wire should burn with 1/4 inch to 1/2 inch stick out.
Or you can pry off the metal clip. gently pull back the boot and look in the slot where the trigger wires come out and see how many strands of wire are broken. They all may be broken and the liner is
carrying all the current.

 

SUCCESS!!!!
I am happy to report that I was able to resolve the issue this way: I bought a magnetic grounding clamp and I lowered the wire speed wayyy down. Night and day difference when I tested it on scrap metal. Much better welds now coming out of the gun. Huge improvement on my tack welds on the VW.

I think my problem started with the grounding clamp. I was unable to find a good ground...somehow I adjusted the speed up too high after that.

Thanks everyone for your input, I couldnt be happier:cool2::cool2::cool2::cool2:

Matt

 

good to heard

 

If you intend to do a lot of welding on auto sheet metal, you will be much happier with the results if you go back to solid wire, .023 and 75/25 gas (don't forget to change polarity). It will produce WAY better welds and almost no burn through. The truth of the matter is that the heat of the welds will cause the joint to shrink, so you want to "hit it and quit it" with each tack to avoid warping and shrinking the joint.

 

Thanks for this. I am going to go back to gas... I ran out of gas, and the local TSH doesnt carry it anymore, the drive is far to get some...just havent gotten to it, so instead of not welding I switched to the flux wire I had, but I am looking forward to better welds without burn through.

 

Also, get used to clipping the little "ball" off the end of the mig wire with some wire cutters. That helps to avoid the sputtering and push back on the wire when you first start a weld. The little ball at the end of the wire prevents your wire from making good contact when the wire first touches the area you are trying to weld. A nice sharp clean end to the mig wire makes better instant contact.

 

Thank you. I am looking forward to much better welds....

 

Another update: Beautiful tack welds, after switching to MIG from flux. Really great results.

To summarize- Bought a magnetic grounding clamp, turned my voltage up and my speed all the way down. Initially was stuck with flux until I was able to buy some gas a few days ago. Now using the gas and everything is awesome. Thanks guys..

Matt

 

Jody (Welding Tips and Tricks .com) taught me about a good ground and it changed my life when I first started welding. Watch his videos on Mig and you'll learn a lot about how to set your machine, gun set up, and mig welding. Aka, GMAW.