Welding Tips and Tricks

I am currently attempting to replace the floor pans in a project car... the pans are formed from 18 ga steel sheet with a thin galvanizing on them.

I am in the process of tacking them in with a Miller 211, C25 gas and .030 wire, er70s6, I think. I am using the settings recommended on the chart on the welder, but am having issues with blowing holes in the metal. If I just give a quick pull/release on the trigger, I don't get any fusing of the metal, but if I hold it an instant longer, it blows a hole in the pan. If I set the machine up for 20 ga steel, when I pull the trigger, the wire tends to push the gun back instead of establishing an arc. I have the ground clamped directly to the replacement pan. Would the galvanizing tend to prevent a good ground?

Would this project be easier with .025 wire instead of the .030?

Thanks- Bear

The galvanizing needs to be hit with a grinder. Be careful not to take too much metal. And yes .025 would be easier but let's throw the chart out the window. Does your machine have specific settings or just an increase value? That would make it easier but it sounds as tho you have too much wire speed. It's preventing it from fusing until heat builds up. Try turning that down. If I have to mig thin metal I will pulse or trigger it not run a hole bead. And hop around from end to end.

The machine setting are variable instead of having specific settings... right now, I am just tacking the pan in position, so I am not running any beads. I will try buffing the galvanizing off in the weld areas and where the ground clamps and change over to .025 wire and try it again... so turning the wire speed down a fuzz may help also? I am much more comfortable with thicker materials...

Thanks... -Bear

.025 takes less heat to burn so you can run colder to accomodate for the thin metal. I realised you were just tacking it just giving you a heads up for later. Wire speed helps you punch through and voltage gives you the heat to do it by my understanding. And yea I feel you, I would rather be building structural and pipe than fiddling with thin stuff. And especially mig. Not a fan. Nothing is outside of my abilities I just don't prefer it.

I have done some auto body welding before... with a tig welder. My tig welder is hard wired in my basement, though, and there is not enough ceiling height for the car mounted on the rotisserie. Moving the tig into my shop would be a lot of work, but I may end up doing it before I finish this project, anyway...

-Bear

You don't need to remove the galvanizing it will just smoke a little more. .030 can be done I am dokng a bunch of 16ga no problems. If it's only panel try silicom bronze you will be very impressed with the results and it doesn't burn theu the galvanizing so rust protection will be good still. If you use silicom bronze you can stick with .030"

Bear,
You need to do what us amatuers with lower end machines do.
Pick your wire size and then play around with your settings on some 18 guage material until you get the result you need and then go onto the job.
Saves me teaching all and sundry within earshot some new words, when unexpected holes appear in something important.
Cheers

I used .023 for a floor pan replacement recently I'll look later today at the volt and speed settings.

pavetim wrote:You don't need to remove the galvanizing it will just smoke a little more. .030 can be done I am dokng a bunch of 16ga no problems. If it's only panel try silicom bronze you will be very impressed with the results and it doesn't burn theu the galvanizing so rust protection will be good still. If you use silicom bronze you can stick with .030"

No you do. Especially with mig.

Ok, thanks, everyone...

Poland, I'd be interested in hearing what settings you used to do your floors...

The sad thing is, a couple of months ago, I bought the .025 wire and tips in anticipation of doing this job... hut was just too lazy to swap the machine over...

-Bear

.023 70s6 wire. 75/25 gas 145 imp and 16 volts. After it was tacked I just back stitched it about 1 to 1-1/2 inches at a time. Used the Lincoln 210 mp.

Thanks, I will compare that to the recommended settings on the machine chart and maybe have a good starting point to work from...

-Bear