Can I weld (mig weld) on a headache/bed rack that is mounted to my truck? I would attach the welding ground directly onto the headache/bed rack, but am I'm concerned about the computer getting screwed up.

 

I've done it, dont know if it is a good thing or not. Maybe unkook the bats as a precation.

 

I am no expert but I have welded on my bumper and my exhaust. I unhooked both negatives on the batteries with no problems at all.

 

Yep all you need to do is unhook the battery, if you leave it connected the power from the welder will go through your computer and fry it.

 

I did 90% of the welding on my hauler bed while on the truck without unhooking anything but I always kept the ground close. Craig

 

Yes you can. Take a couple of precautions before lighting the arc. Disconnect both battery negative terminals, get your ground as close to the work as you can and you should be OK.

 

as most everyone said, i always disconnect the battery ( + and - ) before welding on a vehicle as a precaution...

although when i took my cousins truck to get a muffler welded on they just put it on the lift and went to town. no troubles and this was at a respectful shop...

i guess to each their own everyone does it differently

 

As long as the ground is in-between the welding area and the computer, you're good. I always unhook the batterys before welding on my truck.

 

I've welded on my truck without disconnecting the batteries, but kept the ground close. If in doubt, unhook them.

 

I have never unhooked the battery in anything i weld on , and i have never had a problem.

 

I welded without problem on hundreds of vehicles, tractors, etc without disconnecting anything till one time- Toyota PU tailgate, ground close, fried the computer.
$800!!!!
Now I always disconnect the batteries.

 

So, if I disconnect the ground on both batteries, I'm OK to MIG weld on my truck?

 

Lots of welding has been done on my mega cab...afterall, it was stretched.
Welded with batteries unhooked for that. Did not disconnect for the welding of the hitch brackets to the frame. Next we will be welding adjustable brackets to the frame for some 'real' side steps. Whenever we get to that is a mystery right now though.

Scotty

 

Thousands of welders here in Texas use their flatbeds every day for work benches. They clamp the ground to the bed and lay the work right on the bed to do the welding. Never seen any of them unhook the batteries.

 

I've posted this before, but maybe someone might be interested in it;

I have been operating a portable welding business for 20 years now, and without fail, if I weld on the back of my truck, (93 Dodge diesel), and do NOT disconnect the battery, the electronic Throttle Position Sensor becomes inoperative. I have fried this little component 4 times now.

At first, I held many of the opinions that have been expressed here; keep the ground clamp close to the work area, disconnecting the battery causes more problems then it solves, etc. But since I started disconnecting the battery, (when I remember!), I haven't had any more problems.

As for explanations of WHY things 'fry', maybe this will help;

Electrical components are at risk NOT from the normal voltage and current given out by a welder during use, but instead from the very large voltage spike that occurs unavoidably when the arc is switched OFF.

This spike occurs because the high current path through the welding cables, the weld pool and the arc itself will set up a significant electromagnetic field around itself. When this field collapses very suddenly as the arc is switched off, it will induce a voltage pulse in nearby electrical circuits even if they are electrically isolated from the actual welding current path.

The size of this pulse is determined by a whole host of factors, but long connecting cables are particularly good at suffering from this induction effect, hence the need to disconnect them from sensitive circuits.

The welder's transformer itself also generates a big spike as its electromagnetic field collapses when the arc is switched off. This is directly carried into the component being welded and so distributed to anything connected to it.

Some mechanics disconnect the battery during welding in the mistaken belief this will protect those sensitive systems on the vehicle from voltage spikes. Others think that positioning the welding ground clamp near to the weld area will offer protection. In fact neither of these methods offer 100% assurance that the voltage spikes will not cause irreparable damage. The only way to guarantee protection is therefore one of three ways in order of effectiveness:

1.Remove the object to be welded from the vehicle and weld it before refitting it.
2.Fit a surge protection device to the vehicle being welded.
3.Disconnect all sensitive equipment from their connecting cables.

Having said all this, welding on a vehicle without taking such precautions doesn't mean it will always be damaged. It does however mean you are risking damage and given the cost of replacing components you have to ask yourself whether it’s a risk that is really worth taking.

chaikwa.