Tig/Sheetmetal advice needed

[JPH]

Hi Guys
Let me start by saying new to the Tig However very fluid with stick and Mig.
My question is: I am splicing a quarter panel to a car horizontaly(1968 Olds) Roughly 20 guage metal. Any helpfull hints to getting this done succesfully without distortion?
Here is my plan
(1) .040 Red tung.
(2) Butt joint(tight)
(3) Will run at 42 Amps
(4) Have a syncr 200 machine
(5) Filler rod if nec. is .025 from my mig because i have it already
(6) How short or long of a pass can i make without warping the panel???

Am i in the right direction or would someone have a better idea.
THANKS
John

[DSW]

Instead of a but seam you might try to overlap the panels. Eastwood's sells a flanger for doing this with body panels. Looks like a pair of visegrips with a step welded to each jaw. Creates an offset in one panel so they can overlap. If you have access to a mill its not hard to build, if not just buy it. The panels will sit flush after flanging and give you a double thickness of metal to help prevent burn thru. Make sure its the step one and not the V shaped one they have thats designed for but joints that are to be mig welded.

I'd practice welding on some scrap first rather than the actual body.

[welderman23]

yep your on the right track.
i wouldnt do more than a 1 inch weld at a time.
then move to the end of the piece for a nother 1 inch bead.
for auto body work i have found that it is EASY to warp the metal with tig

myself ...i always use mig

[monte55]

From what I've seen on TV they like to butt weld panels. A flanged joint probably would be easier to weld but allows rust to develope between the gaps of the metal which may show up later through the paint. I have the Vice Grip type flange tool and the air/hydraulic flange tool. I think a butt weld would be best if you have the skill to do it.

[bvweld]

Hi Guys
Let me start by saying new to the Tig However very fluid with stick and Mig.
My question is: I am splicing a quarter panel to a car horizontaly(1968 Olds) Roughly 20 guage metal. Any helpfull hints to getting this done succesfully without distortion?
Here is my plan
(1) .040 Red tung.
(2) Butt joint(tight)
(3) Will run at 42 Amps
(4) Have a syncr 200 machine
(5) Filler rod if nec. is .025 from my mig because i have it already
(6) How short or long of a pass can i make without warping the panel???

Am i in the right direction or would someone have a better idea.
THANKS
John

IMO if I were doing it I would use MIG. Mainly your heat input will be less due to your speed of travel will limit your heat input - less warpage. You will still have to weld incrementaly as suggested. As Monte said, I don't like flanging either , it could be a catch point for moisture- salt etc. It can be TIG welded if that is all you have- just watch the heat input. Pulsing would help. Good luck

[Hankl]

Another vote for Butt welds, also, short welds, an inch at a time max. Key to keep warping down to a minimum, is Dollying the weld down, basically, restretching the metal, from the contraction of welding. When you weld a small item like this, the HAZ shrinks, plannishing stretches it back again. Plannish as soon as possible, to use the heat to your advantage.

Hank

[JPH]

Thanks for all the hepfull hints. Given the long flat surface and the ability to control the heat is my reasoning to use the tig. I am also told it has less of a possibility for warpage.(I'm sure this depends on the talent level). If i did this with the mig i can guaranty warpage, along with a ton of grinding the weld(generating more heat). This weld will end up being every bit of 5FT long. Also it must be a butt joint as it will be seen from inside the trunk and given the level of restoration on this vehicle a lap joint is not accceptable.
Looks like i am ready to give it a shot. I will let you know how it works out.

THANKS again for all the terrific info
John

[Craig in Denver]

Imho

I'd gas MIG it with .023, one tack at a time; less heat input.

If the quality of restore won't even allow a flange inside the trunk AND 5' long; plus you're learning TIG. And, if this is on a flatter section of the panel (no curve to hold shape), more trouble. Also, horizontal welds are the toughest. I wish you luck.

FWIW: My sig gives my qualifications......none.

[Fortyfords]

If your butt welding use mig ,with 23 wire.low setting
wire speed up a little.
Use klecko (sp) clamps to keep your seam aligned .
With the mig ,you can stich it ,by jumping around ,keeps the HAZ way down ,less warpage

If you use tig you better keep the hammer and dolly close by .
After HAZ better shrink/planish the area quickly or warpage is a fact of life.

I prefer mig.

Rich

[ProWorkz]

Mig

I use my Miller Passport Plus for all my sheet metal work. No warping and no issues...... I just finished up most of the welding a few days ago on my 39 chevy truck with a 6" chop. I still have a lot of finish sanding to do but overall I will have very little bondo to put back on the truck. I had originally cut the roof out to make a rag top. Then decided to go back to a hard top so I had to weld the roof back in. The trucks roof already had dents in it. So the dents are not warping. I do very small HOT tacks every inch. And then tacks again every half inch and so on. Here are a few pictures of the sheet metal work. Absolutely ZERO warping.









You can see the whole chop process here...... http://www.proworkz.com/39chevybuild.htm

If anyone needs help with body work and sheet metal PM me.....

[aametalmaster]

ProWorkz nice work and pics. My buddy tigs all his body panels also. I just saw a replacement floor in a Crosley and it was perfect. But he was a 30+ year sheetmetal worker too...Bob