I'm interested in finding out what to disconnect before mig welding on an auto body, frame or exhaust. My concern is frying the computer or other electrical components. I've heard to disconnect battery leads and all chassis grounds to disconnecting nothing before welding. Any help out there? Thanks in advance.

Just disconnect the battery and your good to go. The newer cars are the ones you really need to do this in. It can be a hit or miss leaving them hooked up so why chance it.

RandyB.

I weld on cars nearly every day. We do about 150 cars a month at the shop, most needing welding of some kind. We don't disconnect batteries unless the battery is being removed. We do however use an "isolator" that hooks to each battery terminal and "absorbs" any shock.

But I have to say, over the months and years, a LOT of cars get welded on where the tech forgot to install the isolator. I have NEVER, EVER seen ANY damage what so ever to ANY componant of ANY car. I have seen seats burn, carpet, seam sealer in flames, glass damaged by sparks, etc. But NEVER have I seen or heard of from anyone an issue with a welder damaging anything.

Let me put it this way, even disconnecting the battery is overkill. Nothing it going to happen PERIOD.

The basic rule is to not weld within 18 inches of a computer. I do it all the time, sometimes it just can't be helped. The real concern is if one is stupid enough to ground the welder on one side of the computer and to weld on the other and SOMEHOW weld something that will make current actually go thru the computer. It is crazy and an overkill to worry a whole lot about it. Disconnect the battery and NOTHING will ever happen.

Brian

I welded for a bunch of years on injection molding machines that were
all completed. Almost any kind of electronics you can think of are on these.
My rule of thumb was to put the ground on same piece of metal you are welding. Never had a problem. However, another guy put the ground on the
frame and welded a sliding assembly on the frame. The transducer cable
had some shielding that he cooked. Was the only path for the current since
the assembly was setting on micarta and grease.

I've forgotten to disconnect things sometimes with no negative results.

I always place the ground to an area very close to where i'm welding, since the High Frequency start in the TIG machines concerns me with electronics.

SS dave .

I too work in the plastics industry and we have 2 machines from France that absolutely have to be fully unplugged from the PLC's or we'll fry chips.
Needless to say these 2 machines were prototypes and are a real bitch to get boards for. Now as for our Huskys, they too are very tempermental. The sumitomos, nesseis, and Van Dorns, there is no issue, but I still always power down. Why take chances.

What plant and where do you work?
I work for Captive Plastics in Ky. We make whiskey caps and PET bottles

RandyB..