Welding on vechicles

[iso50]

Ok, I know its a dumb newbie question, but its always better to ask and feel silly than do it wrong and feel stupid.

How safe is it to do body repair (MIG) on a vechicle (1993 Ford F-150) while the whole thing is still together? I know welding on the bed near the fuel tanks is a bad idea, but what about around the door and the extended part behind it? I have rust issues, and would like to do it myself, esp after finding out what the shop wants. Btw, there is rust on both sides of the truck.

[dyn88]

mig "should be fine" Ive seen many body shops do it, but remember to establish a good clean ground directly near the repair. do not ground on the frame and weld on the body.

[stinkinlincoln]

I remember reading a post a while back on this topic, you should do a search for it. Several individuals in the know gave their opinion on the subject. I believe the consensus of opinion was that it was safest to not do it. If it is necessary, disconnecting the battery, coil and any sensitive electronics (particularly the engine control computer) is a must. Also having a good clean place to hook the ground clamp near the weld. I'm mostly just paraphrasing the old post. There were also some horror stories about arcing inside bearings or gear cases . In case you didn't know, a full gas tank is much less likely to explode than an empty one. Incidentally, I have arc welded on 3 or 4 different vehicles without disconnecting anything and had no problems. However, I won't be doing that anymore after reading that other thread

[iso50]

I am more concerned about fuel explosions.

[Sberry]

Welding on trucks with fuel tanks is done all the time. Make sure they dont leak, dont blow grinding or weld on them, shield them if you can or have to with sheet metal. I never disconnect anything electrical when working on cars. I always make sure to ground on the piece I am welding on as there are so many interconnected ground wires in wire looms anymore it would be easy to set up a ground loop thru a wiring harness. Also watch for fuel lines and most important vapor lines, lots of them are plastic, look inside frame rails and locate these lines so you know where they are at.

[VBI]

Iso 50

Sberry brings up good points, cautions. I know a few body-men who do not disconnect the battery while welding on the body itself, but they all use a magnetic ground as close as possible to the actual weld work. Furthermore they also connect a 10 gauge wire with alligator clip ends to the body panel they are welding on and to a common earth ground, i.e. water pipe, building beam, in-ground hoist. They say they use the procedure every time as it is considered mandatory where they work.

Better to be safe than sorry.

[migmaniac70]

Those magnetic ground are GREAT especially if yours is only one of those cheap *** battery charger type. Just slap the magnetic one where you need and it wont come off.

[burninbriar]

Befor you start welding make sure you know whats on the other side.Some times there may be undercoat or insulation thats flamable.I set a car door on fire once when I was a kid on the farm.

[aametalmaster]

I used to weld trailer hitches on trucks 3 or 4 a week. I never unhooked anything but that was pre computer days. As everyone else says watch out for hidden lines and small fires on the backside. I was welding a hitch on a new 13 mile Ford F-150 and heard a little pop. That charcol cannister thingy on the engine lit off and was burning. If it had not been for the pop i never would have seen it. I got to see my dad burn up a brand new '64 Ford Galaxie SW when i was a kid. He hit a fuel line welding on a hitch. That kinda stuck in my head...Bob