i can barely weld but figured i would take a shot at mig welding my exhaust.

i know that i have to disconnect the battery.

but here is the real question...

when i am welding in the garage i ground the welding material with the given ground clamp.

if i am going to weld on the truck do i have to use the same ground clamp on the work surface, or is the truck already grounded via contact with the ground sufficient?

the clamp just before the muffler isn't holding very well and dont want to use exhaust tape if i dont have to.

any help?

thanks
jay

Ground the clamp to the end of the exhaust pipe, since thats what you will be welding on. Start with a few tacks on it, then fill it in all the way around if you can, but be careful not to blow through the pipe. Maybe practice on some extra exhaust pipe first to get the hang of it.

Good Luck.....

if i am going to weld on the truck do i have to use the same ground clamp on the work surface, or is the truck already grounded via contact with the ground sufficient?
1.The truck is not grounded to the ground. It sits on rubber tires, rubber is an insulator.

2. It doesn't work that way anyway. The welder needs a complete circuit to work. Ie, the truck has to be grounded to the welder.

sweet i thought so, but wasnt sure.
i have been screwing around doing some stitch type welds on some scrap exhaust pipe that i have laying around. the last thing i want to do is ruin something or screw the pooch bigtime on the bko, and wind up having to have somebody unscrew my damage.

nice,
thanks for the input y'all

It should go without saying but...

watch for gas fumes and don't set the carpets on fire either, and whatever you do don't fuse the muffler bearings to the case !

Sixlitre

It should go without saying but...

watch for gas fumes and don't set the carpets on fire either, and whatever you do don't fuse the muffler bearings to the case !

Sixlitre

aaaahhhhh yeeeeesss ... many a muffler bearing has been destroyed in this manner.

be careful welding exhaust and body panels. The steel ain't very thick, so if you start getting it hot your just gonna blow through it. Use short bursts and weld a bead in a series of short shots, let the steel cool in between each burst.

On a exhuast system or body panel or frame rail, clean all rusted areas with a wire brush (preferably on a grinder) to clean the area, and your gonig to need to get the ground on a good piece of steel too.

You don't HAVE to disconnect the battery, but since you already did, no big deal. Clamp your ground as close as reasonable, to the area you want to weld. The size of the weld wire makes a difference here, too. Ideally, you'll use .023, but .030 will work too. Your voltage should be set fairly low... somewhere between 9-12V, IIRC (yeh, it's been quite awhile since I've done anything that thin). Then, just follow the rest of the advice - tack welds, to hold it in place, then stitch weld around the pipe