Sheet Metal with a Stick welder help

What Ernie said. You might have to switch to 6011 in 1/16" or

Expect to have some burn though issues s> >

Wow, now *that's* what I call a challenge! Talk about 2-hand welding. What is that, like 20-22 gauge sheet metal? 1/16" 6013 at about 40 Amps max (DC) would be one hell of a challange without chill bars. I've done this kind of repair work before, but I resorted to O/A and brass. (brazing in new pieces with Oxy Acetylene), and that may be a better approach since that way you can get an air-right seal (especially for floor boards).

What's a chill bar? Don't think I've ever seen one.

Brazing might be a really good choice here.. My other thought was that it might be much faster and much easier to go in with a small MIG welder that you could rent from Home Depot.. (e.g. Lincoln SP-135)

I've welded thin rusted out exhaust tubing before -- it can be done with 6013 running really cold. If I had to do that one over again, I think I would have grabbed a small MIG and been done 2 hours sooner.

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How good of a weldor are you? I am a very poor one and I've gone down to 1/16 with 3/32 6013 (before I got my baby MIG). I _always_ burned through in some spot(s). It was a real hold-my-breath experience, hoping it wouldn't burn through.

A chiller is a hunk of copper that you hold to the backside of the weld. It reduces burn-through by dissipating some of the weld heat. Being copper, the weld doesn't stick to it if there is burn-through. I suppose aluminum could be used also.

Bob

A 'chill bar' (usually copper) is placed on the underside of the weldment to absorb excess heat, control penetration, and minimize warpage etc.

True, but joint prep may be an issue if its old rusty automobile floorboards, but I guess thats no biggie to grind clean all edges.

Thing is, exhaust pipe is much thicker than the sheet metal used for autobody panels/floorboards. Correct, 6013 rod (A/C) is very doable for exhaust pipe, I just think it would be challanging, expecially closing up both sides of the lap joint (underneath etc).

Yeah, your probably right. You can turn down the amps and practice a little on the old floorboard that he pulled out to get the right wire speed and current setting.

Come to think of it, I may have seen them.

The exhaust in question was welded at about 50A? DCRP w/ 6013 on a Miller Aerowave. It wasn't pretty, but neither was the car it was being reattached to. I should also add that proper surface prep was not done, probably just adding to my hassles.

The floorboard probably is a little thinner, but if you ran it cold enough and did not have to change positions, just a nice long horizontal bead, I betcha it's doable -- especially if the metal is clean.

I think MIG is the way to go on this one. He could potentially practice and get his settings down with stick, but he could also MIG it real quick and be done. And with the availability of small MIG equipment for a small fee, it seems like a good choice.

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I think I am going to cry...

...using an Aerowave for STICK Welding...

...I didn't think anyone could be so cruel.

What? - whattaya got against 6013 ??

:) ...too funny

Well, I know it'll sound like one of those "My old man used to" stories BUT my old man restored a half dozen cars in his younger days with beautiful results. All fifties/sixties English cars except for a Citroen 2CV. Sheet metal was between 18 and 20 gu on the Brits- dunno about the Citroen. All of this was done with 6011 rods on a buzz box AC machine. Like they say, "it's the Indian not the arrow that counts".

Ken

I had been wondering about using 6010/6011 for something like this, rather than 6013. I realize it seems counter-intuitive, but in my (admittedly limited--but growing) experience, I find it easier to avoid blowing through with 6011 than with 6013 on thinner material. Even though 6010/11 is far more aggressive, and would certainly blow through in a hurry if one just tried to run a stringer pass, the ability to do a stitch pass and "fast freeze" the puddle seems to make it easier to control how hot any particular spot is getting. As I have gained more experience and control in stick welding, I find myself reaching for 6011 more and more often.

Now, I have not tried this on 22-24 gauge metal ... maybe this is a good excuse to go home and experiment!

I have used 6011 for many such applications because the fast freeze eliminated burn through. My machine is a Miller Thunderbolt AC. I turn it down to 30-35 and get after it. The important thing is to stitch the weld because the thin sheets will warp badly. I find that lap joints work best for the thinnest of material.

Scott Young

Oh, yeah -- how could I forget about the possibility of warping? (I guess I haven't been doing much work with sheet stock, of any gauge, for a while.) Other than stitching the weld, do you do anything else to try to prevent or control warping?

Andy

Ok, I have seen the term before but i still don't know what it means. What is stitching the weld? Do you mean like a bunch of tack welds?

Thor

A stitch weld is a series of short welds usually 3/4" - 1" for me. You place a stitch and then skip a considerable space and then place another stitch and so forth till you have encompassed the area. Then back track till you cover all the area.

Andy,

Using copper backing plates will help control warpage. I have used larger than necessary electrodes with the heat turn way down. What you end up accomplishing is an arc that welds the parent metals together and deposits very little electrode. You will be surprised at how easy it is to get good welds and minimum warpage. The only problem is you have to be able to hold an arc which is not easy at first. The down side of this last procedure is you will get goblets of electrode that will have to come off at a later time for it to look pretty. Since most super thin sheet is sanded this is not a problem.

Scott