Thanks to all of you who responded to my earlier post on buying a welder, as well as lots of other welding-related posts, I bought a Millermatic 135. I'm excited. graemlins/hurray.gif Since I'm planning on only welding patch panels and not doing frame work, I think this unit will be adequate for me.

Now for the fun part. I have to learn how to use it. I went to a salvage yard, and a really nice guy gave me some steel scraps of various thicknesses, including sheet metal, to practice on. So I'll be learning how to mig weld for the next two weeks, and then I have a week's vacation at which time I plan on welding on my patch panels.

I've read the Basics of basics and lots of other welding posts, but I still have a couple of other questions, the first of which is embarassingly BASIC: graemlins/clonk.gif

1. Since the welding wire is electrified when welding on a patch panel, and the clamp is clamped on close by to complete the circuit, doesn't the whole car body become one giant live electrical contact? If, hypothetically speaking, (and I don't plan on doing this) you were to touch the car body while welding, wouldn't you get a shock? Can any damage occur to other parts of the car or electrical parts when welding on the body, like through the ground straps? Should they be removed? Any other precautions to take before doing welding on the body?

2. What about the gas tank? One of my patch panels is the lower rear quarter patch. Should I remove the gas tank before welding? I want to be as safe as possible, but I don't want to go overboard, either.

3. What's the best respirator to use while welding, the canister type from the hardware store, or is there a special type (I'll check with the place where I bought the welder on this, but they didn't offer to sell me one, and I forgot to ask).

Sorry for the long post. Thanks for your help, and I'm sure I'll have more questions in the weeks to come.

1.NO any electricial compenats within a 12in area should be removed
2.Yes without a doubt...whats overboard??
3.The best mask 3M 07187 a good mask 07183 an ok mask 07189. Only use a mask APPROVED for welding period!...Eric

1. You need to watch were you place your ground, although this is more emphasised in industrial applications, you never want to pass that current across a bearing or any other machine type of componet. When welding on the body, place it as close as you can.

2. I would pull the gas tank. And always remember, its the fumes that are flamable. If you are doing this sort of restoration, time to clean it out or replace it anyway.

3. If you have GOOD ventalation you shouldnt need a resporator. I use a couple fans around when welding.

Other item:

Wear boots without a open front (no laces) and pull your pants down over them. This keeps you from catching any sparks dropping off.

Also, think about your work area, sparks go everywhere. I love to see guys welding in their home garage which is not finished with drywall (just has exposed studs). This isnt the smartest thing to do. Granted you could go a lifetime and never have a problem, but there is that one time......... Look for cardboard boxes laying around, ect.

Don't attach the ground cable to any engine component, alt bracket. etc. if the current flows through the engine it can arc the bearings, not good. :D

first off.. nice choice on the new welder!! graemlins/beers.gif
What I learned was to watch your surroundings like they said above, anything flamable will light, simply because of murphy's law. Wear good gloves with sufficient coverage to keep flack out of your cuffs and if you happen to be upside down or perpendicular to the ground you might want to get the leather jacket, or vest depending on your job. My father in law who was a carreer welder only just began using ventilated helmets for certiain processes because of work hazards. Doing this for a living 8 hours a day, everyday, will get you sick without proper ventilation. I remember a post about a member of TC getting an alergic reaction to welding gases. NO fun at all. Those small welders masks as described above, are just the key but if you are outdoors or have very good ventilation I never saw an issue. Common sense plays a big part. Millers website is pretty good and they have some online tech courses you can click through which will give you a pretty good intro to welding. Enjoy buddy!
miller electric homepage (http://www.millerwelds.com)

Actually, as far as electrical goes, I've seen voltage regulators go out due to welding with the battery hooked up. It's always best to unhook the negative battery terminal when doing any welding on a car, especially a newer efi car.

I also bought a millermatic 135 and I love it.Im going to get a respirator though I dont want to take any chances.

I always remove the neg. battery cable or you can buy a thingy that goes across the battery posts to stop spikes. This is for newer cars,not an old chevelle but you can easily fry the computer or other electronics in the vehicle.Even using a stud gun we take those precautions at the shop i work at.Ever price a ECM on a late model car? Not worth the risk. Also not worth the risk welding without a respirator, ask SEVT_CHEVELLE. It only takes a breath or two to cause lasting damage.

Thanks for the help so far. I can't find any welding respirators at the local stores, so it looks like I'll have to order them online. Until they arrive, I think my regular vapor/charcoal respirator should be O.K. while I make a few practice welds, if it fits under the mask.

My body repair book strongly recommends a welder's cap, to prevent scalp burns. Sounds like something else I need. This same book shows a photo of a guy demonstrating practicing MIG welding on some small steel coupons, only a couple inches square, while holding them in place with his bare hands! -and the sparks are flying! The clamp is attached in a location opposite where his fingers are. The photo caption says "don't try this at home", but still, I don't understand why he wouldn't get an electrical shock.

As for the gas tank, I'll take it off. It has already been off and cleaned up, but I don't want to take any chances.

Yesterday I set up the Millermatic and have everything all ready to go. Now I just need a little more courage to pull the trigger.

Don't waste time learning how to run a bead. All you need to know is how to stitch. Even if you decided to weld a frame you would need to stitch it to avoid warping it.

I weld without gloves a lot.Maybe not the smartest thing, but i never got a shock,a few burns-yes. graemlins/clonk.gif

The guy doesn't get shocked because he is not part of the circuit.
Current need to flow through your body to shock you. Metal conducts electricity 1000's of times better than your body ( unless you are wet ).
The current takes the path of least resistance and will flow straight from the ground clamp, through the metal to the wire in the gun.

You'll find that fans blowing on the job will also blow the gas away causing welds full of bubbles.

Read this thread! It's just your friggin health! (http://www.chevelles.com/forum/ultimatebb.php?ubb=get_topic;f=3;t=008203)

DO NOT USE A "REGULAR" VAPOR RESPORATOR!! . Every particle compound follows a different path, every particle compound needs a different way to stop it. BUY A REAL WELDING RESPORATOR as Eric pointed out. The disposible one he mentioned is only about $18.00, for Gods sake, spend the lousy $18.00 smile.gif

The rule on clamping is simply get it as close to the weld area as possible. It is not a big deal, the current will flow across the car just as your battery current does. But the rule is more so you don't make a mistake and do something like put the clamp on the body, weld on the door and weld your hinges together from the current flowing thru them!

I have seen a guy MELT the throttle cable in half on a hot rod once. He put the clamp on the exhaust pipe, the engine has rubber motor mounts right? The exhaust is rubber mounted to the frame right? Well, the only place the current could go is thru the beautiful Genie shifter throttle cable and it melted it in half.

By the way, I HIGHLY recommend a good pair of supple (sp?) leather welding gloves and a good welding jacket. The gloves are about 20 bucks and WELLLLLLL worth it. The jacket can be bought on eBay (search under "Tildon" ) for about $20.00.

It is a lot easier to lay nice welds without hot beebees of metal in down your shirt or pants. smile.gif

That's good stuff....I'm all for stoppin' the beebee's graemlins/thumbsup.gif

I use a cotton welding apron (I weld from my wheelchair). I haven't done much in my garage, but I know I need a better mask.

Will this work?

Mask (http://www.keysan.com/ksusa19b.htm)

DG, I dont see that part number in my '03 3M catalog but the info on the site lists that mask as welding.

The mask I use, uses that purple looking disc on the bottom which is part number 07183.

For more info call 1800-243-4630

Edit looked farther down
http://www.keysan.com/ksusa19.htm#MMM999530921852