Novice welding safety quetion

I'm in the process of cutting the fenders to fit the big Hoosiers on Tom Celica. Now, eventually, I'll need to weld the inner and outer fenders back together in the rear. I have a bit of time because I want to run it first to be sure I trimmed enough.

But, when I weld on the car, I want to do it safely. I've heard people talk about removing the fuel tank before welding on a car, or removing the ECU. Do I need to do that, or anything else to make sure I don't mess anything up?

Thanks,

Ed

WEAR A GOOD MASK.

Disconnect the battery is always good advice.

Put the ground clamp AS CLOSE TO THE WELD AREA as possible. You don't want electricity going through things like bearings and such to get to ground.

i've never heard of an ecm getting fried by a welder, and i've also never heard of a car 'sploding because someone was welding close to a gas tank...

if you are worried about either, then remove them..

as long as the electricity has an easy path to ground, you should be good... if you are welding on the body, then put the ground clamp on the body.. if you are welding the exhaust, then put the ground clamp on the exhaust. also make sure you don't use a movable suspension point as a grounding point- i once tried to use a lower rear control arm for a grounding point for some stupid reason, and kept getting mad because the wire would just push out and there would be no sparky action.. it took a few minutes for me to remember that rubber is a damn good electrical insulator and that there was a rubber bushing at each end of that arm- luckily no one was there to see it..

i also fried a ground strap because i was trying to weld the exhaust on my Nova with the ground clamp put on the body.. the battery was out of the car, so that ground strap from the front of the engine to the subframe was the only ground path between the exhaust and body- if i would have had the stock rubber body mount bushings and not the solid aluminum ones there would have been no ground path... i was welding on the exhaust pipe right in front of the rear axle, and the ground clamp was on the leaf spring mount about 8" away... it was welding nice for a few seconds, then i heard a pop and it stopped working.

electricity is easy once you figure out the simple things...

I have nothing to offer since all the welding I do is on cars without ECU's, and with points distributors with condensers, which I might add, have gotten somewhat difficult to find.

Don't worry about it. I've never pulled the ECU or a fuel tank. I do disconnect the negative battery terminal and ground as close to the weld as possible.

Being safe means keep a fire extinguisher handy just in case. Use a welding hood so you don't go blind. Don't pick up that piece you just welded because it's hot and will burn the snot out of you.

Oh, and don't try to weld anything to the ECU or the fuel tank. That would probably end poorly.

Check where your wiring harness is routed so that you aren't frying wires. Wet towels work well to shield anything close to the welds thst is flammable.

Brazing?

Cool, thanks guys. Good tips, especially on where to ground. Since it's rear quarters, and I have to grind the paint back anyhow, I'll grind a spot on the body for the ground.

Thanks!

Just keep your hands and feet inside the ride at all times and you'll be fine.

...and disconnect the battery.

My understanding is that the high frequency start on tig welders is what can fry electronics. I've mig welded on several hundred modern cars without disconnecting the battery, so far so good.

Maybe I got lucky also, but it's a two minute deal.

Study this photo, and do everything different:

DARWIN!!! Where are ya when we need ya ?

Read through his site. Recommended reading for anyone involved with welding anything!

http://www.weldreality.com/

It's stuffed with safety information. Things like which gasses from different metals to be aware of, as well as why they are harmful and what to do about it.

slantvaliant wrote: Study this photo, and do everything different:

C'mon, thats quality lumber right there.

BBsGarage wrote:

slantvaliant wrote: Study this photo, and do everything different:

C'mon, thats quality lumber right there.

Exactly! And he has the wheel chocked so it can't roll. Looks to me like he's the very paragon of safety.

Yeah, disconnect battery, ground close to where you are welding and have a fire extinguisher handy and you should be fine.

Travis_K wrote: .... have a fire extinguisher handy.

Keep a wet rag nearby also. A fire extinguisher blasts the project with powder, overkill for a little insulation fire.

Welded up the entire cage in my Civic with a stick welder and all we did was make sure the ground was good and close to the weld, disconnect battery and had a hose near by to put out those pesky undercoating fires. We also employed the wet rag technique when welding near flammable/combustibles like the fuel tank which is right behind the front seats and under the rear seats. Didn't have any issues at all.

Plus a billion having good welding Helmet (hood) and long sleeves of a heavy canvas or leather are nice as the hot bits falling off when you weld over head can really burn the tar out of you. You can buy welding jackets or sleeves commercially or find a good heavy canvas shirt or old leather coat at Goodwill and be just as protected. Oh and heavy full leather gloves at the least of not real welding gloves. Bought mine at HF for less than $20. Work gloves work in a pinch but the cloth/nylon backs can burn or melt right through and burn you, I learned that the hard way. Finally as I have prettled on long enough, long pants preferably cotton or denim. Nylon work pants will melt when slg hits them and burn the tar out of you. I have even gone over kill many times when wleding over head and wear a baseball cap backwards to keep metal from getting in over the top of the hood. Be aware any skin expsed to the arc will be getting alot of UV so you can get a wicked welding sun burn if you aren't aware. I tend to look like I am on the bomb disposal unit when I go to do any major welding. Silly looking but safe.

Wear a respirator rated for what you're doing.

Welding anything galvanized releases something horrid that will berkeley you up. If I recall, welding stainless releases hexavalent chromium. Not good either.

And never, ever clean part with brake clean prior to welding. That make chlorine or phosgene gas or sumpin' awful. Use acetone or lacquer thinner, let it dry thoroughly before striking an arc, and move the solvent container and any rags away...

Remove your ecu. If you have an iffy ground you will fry it. I know because I did, and the battery was not even in the car. All I know is that the car ran fine, I welded in a full cage, and the car did not run fine. 2 weeks of troubleshooting later and we discovered the ECU was bad. Unplug or remove it and one less worry.

mr2peak wrote: Read through his site. Recommended reading for anyone involved with welding anything! http://www.weldreality.com/ It's stuffed with safety information. Things like which gasses from different metals to be aware of, as well as why they are harmful and what to do about it.

I can't seem to find the safety section on there. Can you point me in the right direction?

Do not wear jeans frayed near the crotch or you'll look down and find your testicles on fire.

And, yes, I did.