Author Topic: flange method quarterpanel welding  (Read 4130 times)

Offline nr1freak

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flange method quarterpanel welding
« on: November 25, 2012 - 07:41:52 PM »
hi!

i have prepared my quarterpanels with the flange method for welding them in to my 70 cuda, the car is blasted and has an epoxy coating and the panels have the EDP coating.
after the weld i want to use lead to fill up the seam on the outside (with acid free tinpaste to prevent oxydation) and rubber filler on the inside to prevent moisture from getting in but will this be enough?
i have heared the plate-to-plate full-budweld method is ofcourse better for having no seams but i think it would warp too much and hammering the metal straight would cause weak areas in the panel.

anyone used the flange method before?
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Offline Topcat

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Re: flange method quarterpanel welding
« Reply #1 on: November 25, 2012 - 07:53:20 PM »
hi!

i have prepared my quarterpanels with the flange method for welding them in to my 70 cuda, the car is blasted and has an epoxy coating and the panels have the EDP coating.
after the weld i want to use lead to fill up the seam on the outside (with acid free tinpaste to prevent oxydation) and rubber filler on the inside to prevent moisture from getting in but will this be enough?
i have heared the plate-to-plate full-budweld method is ofcourse better for having no seams but i think it would warp too much and hammering the metal straight would cause weak areas in the panel.

anyone used the flange method before?




You will still need to pre heat the panel up if you go the Lead route. Why not butt weld them together?
 
Overlap the new panel over the old. Screw it on, cut both to match. I did my first quarter panel that way before the new repro's came out. Worked out pretty good!

You could use a heat wick paste to help lower heat transfer into the quarter panel.

http://www.eastwood.com/coldshield-thermal-paste.html
« Last Edit: November 25, 2012 - 07:55:43 PM by Topcat »
Mike, Fremont, CA.


Offline grimmey71

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Re: flange method quarterpanel welding
« Reply #2 on: November 25, 2012 - 08:27:30 PM »
 :roflsmiley:What about trying the glue? No warpage that way
« Last Edit: November 25, 2012 - 11:10:53 PM by grimmey71 »

Offline dodj

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Re: flange method quarterpanel welding
« Reply #3 on: November 25, 2012 - 08:51:56 PM »
I did mine with the flange method 24 years ago. I used plain old body filler to clean up the seam after. Needed very little though. No cracks or lifting yet. If I was doing it today, I would really look at epoxies.  :2cents:
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Offline nr1freak

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Re: flange method quarterpanel welding
« Reply #4 on: November 25, 2012 - 09:08:40 PM »
You will still need to pre heat the panel up if you go the Lead route. Why not butt weld them together?
 
Overlap the new panel over the old. Screw it on, cut both to match. I did my first quarter panel that way before the new repro's came out. Worked out pretty good!

You could use a heat wick paste to help lower heat transfer into the quarter panel.

http://www.eastwood.com/coldshield-thermal-paste.html


leading does not require the metal to reach the temperature it would when welding, i've leaded before, no warping whatsoever! that's also on of the reasons i used the flange method, because of the flange, the panel gets extra strength thus eliminating all warping risks.

and i've allready prepped the panels with the flange-seam so no can do on the cutting!
i will punch holes all along the topside of the quarter panel skin for buttwelding so no full weld there.
i was just wondering if there wouldn't be any rust evolving over the years because, eventhough the seam is closed on the outside by lead and on the inside of the car by rubbercompound, there is a minimum hollow space...

i could ofcourse cut the quarter panel a little further so it just touches the bottom edge of the flanged bit on the bodypanel... that would still allow me to do buttwelds on the topside rather than in the punched holes, it would just leave a big gap to fill up with lead...
or just use my fingers to stuff the back-seam full with rubber compound after the leading...

just curious if anyone ever did the flange method before and how it came out, i'm starting to think i went a little hasty on the flanging :-) my friend told me to go at it like that...
oh well, can always blame him if my pricey paintjob goes to sh*t when rust starts coming through!
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Offline nr1freak

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Re: flange method quarterpanel welding
« Reply #5 on: November 25, 2012 - 09:11:04 PM »
i'm not a big fan of bondo... i'll need some on top of the lead for finishing but that will be it!!   :ylsuper:
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Offline Cuda416

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Re: flange method quarterpanel welding
« Reply #6 on: November 28, 2012 - 07:15:45 AM »
i'm not a big fan of bondo... i'll need some on top of the lead for finishing but that will be it!!   :ylsuper:

To be fair, there is nothing wrong with a little filler. It gets a bad rap from all the back yard body men who pile it on or use it as a patch. My instructors used to tell me if it's thicker than a nickle, it's too thick. You'd be hard pressed to find any car without some form of filler on it.

That said, this does bring up a good question about panel joining (I did go to body school for a bit, but went the route of the Marines instead, then college. so I don't really know squat unless you count how to take out bad guys at 500 yards :D ).

When using a butt weld for a panel, what is the best way to prep the seam before applying any other skim coat, paint etc? How do you treat the weld seam to prevent the pores in the weld joint from causing problem later on? Or is it a case of "If you have a porous weld, learn to weld" sort of thing? Is something like duraglass enough, or does it need more?

Not trying to hijack this or redirect, just a thought that popped up before I got o work.

-C

-C
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Offline nr1freak

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Re: flange method quarterpanel welding
« Reply #7 on: November 28, 2012 - 07:43:03 AM »
To be fair, there is nothing wrong with a little filler. It gets a bad rap from all the back yard body men who pile it on or use it as a patch. My instructors used to tell me if it's thicker than a nickle, it's too thick. You'd be hard pressed to find any car without some form of filler on it.

That said, this does bring up a good question about panel joining (I did go to body school for a bit, but went the route of the Marines instead, then college. so I don't really know squat unless you count how to take out bad guys at 500 yards :D ).

When using a butt weld for a panel, what is the best way to prep the seam before applying any other skim coat, paint etc? How do you treat the weld seam to prevent the pores in the weld joint from causing problem later on? Or is it a case of "If you have a porous weld, learn to weld" sort of thing? Is something like duraglass enough, or does it need more?

Not trying to hijack this or redirect, just a thought that popped up before I got o work.

-C

-C



Ok, just to be clear, a butt weld is a single-spot weld right? Like, punch a hole in one plate, put another plate underneath and weld the hole? I'm european, my english isn't so bad but some words confuse me :)

Good thinking though, the body is now primered with epoxy so basically rustproof, the quarterskin has a good primer on it as well so here also, no problem. but if i lead, all surfaces need to be sanded or blasted superclean for the lead to stick. No problem for the outside of the seem but if i want the lead to flow between the small gaps and "fill up" the inside of the seem, where the plates touch, i need to clean the inside also. If the lead would not flow everywhere that would leave small areas bare and vulnerable to rust. Maybe pre-treat the inside with lead also, even if some of it will melt away when welding...
Djeez, i'm going microscopical on this one :)
Might be freaking out too much, just gonna go for it, close the back off the seam with some good rubberfiller, it's not like i'm taking the car out when it's raining so...
Cuda's don't leak oil, they mark territory...

Offline johns cuda shop

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Re: flange method quarterpanel welding
« Reply #8 on: November 28, 2012 - 07:49:18 AM »
:roflsmiley:What about trying the glue? No warpage that way
:iagree:
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Offline Cuda416

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Re: flange method quarterpanel welding
« Reply #9 on: November 28, 2012 - 07:51:31 AM »
nr1Freak,

A butt weld is a weld that joins two edges, often times using several (hundred?) little tack welds one on top of the next to reduce heat. It's not a lap joint which is what a spot/plug weld would require.

Think of it this way. Take two pieces of wood with glue on the edges, and slide them together so the edges touch. That's a butt joint. There is no overlap which is great since the resulting panel won't have a thick spot.

My question revolves around the fact that the weld itself could be porous. What's the best way to treat that type of weld for long term moisture protection?

Thanks for the reply.

-C
70' Barracuda conv. (project)

Offline jimynick

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Re: flange method quarterpanel welding
« Reply #10 on: November 28, 2012 - 11:39:24 PM »
Well, speaking as an old body man, and seeing as how you've already got the thing set up for a flange weld; I'd punch it in the top panel and combo- partial spot weld and panel bond it. Basically, you just leave a small bare spot under the plug weld hole and panel bond the rest. Once the bond had set in the initial install, I'd use the same panel bond to seal/fill the seam and grind off the surplus which would probably require a wee bit of filler and for that, I'd use the short strand fibreglass filler we refer to as Tiger Hair locally. I've still got my lead paddles, but they don't get out much any more (kinda like the guy who owns them). The bonding agent would be a good choice for the inner seam hide as well. 3M and Lord Fusor make a good product and the stuff does NOT fall off. Good luck!  :2cents: