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hi folks

sorry if the question is stupid, but still i rather ask before i make a stupid and expensive mistake :)
if i want to weld something on a car. like exhaust. do i need to take it of. or is enough to disconnect the battery?
does the welding harm the cars electronics or not, if battery is disconnected ? :question:
 

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hi folks

sorry if the question is stupid, but still i rather ask before i make a stupid and expensive mistake :)
if i want to weld something on a car. like exhaust. do i need to take it of. or is enough to disconnect the battery?
does the welding harm the cars electronics or not, if battery is disconnected ? :question:
Disconnect the battery, then it'll be fine. I had to use a welder to heat up and remove the pressed bolts in the stock downpipe/catback flange.

Disconnected battery before hand and had no issues afterwards.
 

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hi folks

sorry if the question is stupid, but still i rather ask before i make a stupid and expensive mistake :)
if i want to weld something on a car. like exhaust. do i need to take it of. or is enough to disconnect the battery?
does the welding harm the cars electronics or not, if battery is disconnected ? :question:
Def a good question. If you dont mind me asking what kind of welder are you using?
 

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It's always good practice to disconnect your battery when doing any maintenance for various reasons. With that said, I'm usually lazy and hardly ever do it unless I'm working on something electronic and don't want to cause a short. I've welded countless floor pans, quarter panels, etc, and have rarely ever disconnected the battery to do so with no ill effects. Still, my advice to you, disconnect the battery.
 

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I have heard it both ways.... I know most muffler shops do NOT unplug the battery. I do sometimes but I welded in an exhaust this weekend and didn't so.

Safe than sorry says unplug it, but I don't think it is needed.
I concur, the way I see it is my 30k dollar car doesn't need to have ANY undue risk...so I unplug it. Takes what? 25 seconds? Precaution never hurts.
 

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I welded in a resonator delete without a problem. I disconnected the battery as a precaution, but with a MIG and the ground clamp fairly close the area you're welding on, it is probably not going to be an issue.

I use an Eastwood MIG 135. Pretty inexpensive and has worked well for me for a few years now. Most MIG welders now should work well enough as long as you buy from a semi-reputable company.
 

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I concur, the way I see it is my 30k dollar car doesn't need to have ANY undue risk...so I unplug it. Takes what? 25 seconds? Precaution never hurts.
I have had people cry about having to setup their settings after a unplug. I just laugh and say well it is better than a tow to the dealership isn't it? I cant remember ever setting up a favorite radio in my car anyways, radio is dead to me.
 

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I've been a fabricator for 6 years now, and let me say this: the myth that you need to unhook your battery is a bunch of...well...****. a welder works by current flowing from the + side to the - Side. the heat made there melts the base material and the filler material. Electricity goes to the best ground, or the ground that best completes the circuit, so you O2 sensor does not have a ground that connects to the welder, then the circuit will not be completed, and the electricity will not flow through a ground into a sensor and burn it out. Also, MOST ECU's use a system ground to turn everything on via a fuse and a relay. so, with the ground circuit broken, electricity cannot flow to anything. A welding basic is have the ground as close to the base material and weld location as possible. It reduced the amperage needed to create penetration. So if you are welding on a muffler for instance, grounding to the muffler is best, or grounding to the pipe a few inches or a foot up stream works too. Make sure your ground is clean, make sure your materials and base material is clean, and your good. I've welded hundreds of exhausts to hundreds of cars and do all the tack welding on the car. Then partial placement welds after that, THEN remove for finish welding. Thats the easiest way to do it, and also ensure proper fitment. Everyone has their own little tricks and shortcuts. this is just mine

links to examples of proper exhaust welding and fabrication:
skip to 7:21

TIG welding, same concept as mig, just different method. Ground is always within 6-8" of what im welding:

Steel tig welding, ground is on the exhaust pipe as its being welded:
 

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As i have been welding for quite some time on customers vechiles as well, on any customers car i undo the battery, I have blown out an ecu on a ford ranger before, either it happened happen stance to me welding, or it was due to welding with the battery connected. it came in running and left dunzo...

I Disagree with some of what the user above me has said. its not all BS....
How ever...I do agree with putting the ground as close to what your working on... if you are welding on a roll cage...ground to that (wont have any problems) ground on the exhuast, and work on the exhuast(wont have any problems), ground on frame, wweld on exhuast, probably will have an issue.
Again having the ground close and directly connected to what your welding on is the key....
 

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My 16 year old self agrees hahahah


Sent from my iPhone using Tapatalk
is that the former you that would agree at the age of 16? because my 16 year old self would agree as well... but my 37 year old self laughs out loud and takes their sh!t to someone else to weld..LOL
 

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Here is my .02, I was a welder/fabricator for almost 20 yrs. I worked with everything from 18 gauge sheet metal enclosures to 2" thick military ship hulls. As long as you ground on the part you are welding on, you will be fine. The current will not pass through any electronics.
I remember back in the day people worried about wheel bearing damage from cars being welded on.
 
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