Hey everyone,

My Chevelle's body/paint is finally all done, so as luck would have it, my new project '65 Le Mans just threw me a body work ringer. There was a little bubbling around the bottom of the roof sail panel, so I got curious, chipped the paint away, and I see someone brazed on a replacement 1/4 panel. Because the brazes are an inch or so apart, moisture got in from behind the panel and corroded the metal a little. It is a lap seam. I want to have this entire seam welded. What do I have to do? I cleaned it all to bare metal, just wondering what to do about the brazes. Melt 'em out with a torch?

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Tony Nausieda
1970 SS 396-4??hp
Frame-off Resto, just painted, awaiting final reassembly.
NOT stock but looks it!

As long as the the panel was brazed in correct alignment, don't worry about it. The rusting was caused by the moisture from the backside not the copper/brass brazing itself. Brass doesn't rust.

Copper/brass torch work was the vogue until until unibody/high strength steel came along in the early 80s.

MIG or TIG between the brass spots, protect the backside w/undercoat and keep on a-truckin'.

I didn't mean to say that the brass was causing the rust..just wondered whether or not I had to remove it before MIG'ing the seam. Seems like the repair was done well otherwise. Thanks!

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Tony Nausieda
1970 SS 396-4??hp
Frame-off Resto, just painted, awaiting final reassembly.
NOT stock but looks it!

To mig weld the entire seam would necessiatate removing the brass. An easier way to do it would be grind out the filler (Bondo) in the seam, leaving the braze welds and then filling the seam with 3-M body 'glue'. It's available at any body supply store. It's easy to use and very strong. It can be sanded down as a filler. No warping or burning the back side of the panel. I would also do the same for the as much as the inside of the panel as possible. You could also make a spray wand for POR-15 to spray inside the 1/4 panel where the window access is. These methods assume that the panel is on straight and is structurally sound. Also, don't use any acid etch or self-etching primer on the braze welds.

I was told that the acids in the brazing would eventually eat through the bondo and bubbles would always be the result...so was that fact or fiction? The guy who told me had a 70 chevelle that had the sail panels brazed, and after years it bubbled up. I had never seen bondo pop up there before so this was a first for me.

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Dave
70 chevelle ss396 conv
66 chevelle ss396 hdp/conv
72 chevelle
TC member #493
Never forget Earnhardt!

I think I'll have it welded up, with the brazing left in place to keep the panels aligned, and finally melt out the brazing and finish welding the seam where the brazed areas were. The body glue is probably as good a solution, but there's something more reassuring about having a weld there. I will definitely be sure to seal off the back of the joint to keep it from corroding any more. Fortunately this is a California car so there's almost no corrosion whatsoever on or around the seam.

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Tony Nausieda
1970 SS 396-4??hp
Frame-off Resto, just painted, awaiting final reassembly.
NOT stock but looks it!

You may have a real hard time welding to something that was brazed. The brazing gets right into the surface of the steel and has to be ground out. If you don't clean it out completely it doesn't weld too well. I learned that from experience.

Peter

The acids you are talking about drptop is from the tinning not being all the way cleaned out of the area. The brazing process itself is a fairly easy and strong weld to make. But you must completely remove the tinning compound. One thing to remember that the brazed weld is not as strong as a mig weld. The brazed weld is bonded together really by adhesion unlike the mig weld which bonds the two together by melting them into one.

Thanks for the help! Okay, so how bout I do it like this: 1) clean the seam completely; 2) stitch weld the quarter panel 1" apart; 3) melt out the brazing with a torch; 4) clean all traces of brazing from the seam; 5) finish welding the seam.

That should work, right?

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Tony Nausieda
1970 SS 396-4??hp
Frame-off Resto, just painted, awaiting final reassembly.
NOT stock but looks it!

The only problem I would have with melting the brass is the amount of heat you have to apply. My concern is for warping the surrounding sheetmetal, even though it was heated up pretty good when it was brazed originally. I'd put some stitch welds in the panel and then grind the brass out. Use a air die grinder and a cutoff wheel to cut on the brass puddle or bead itself, and then carefully grind the rest of the brass colored area in the surrounding sheetmetal as much as possible. Just be careful not to overheat the sheetmetal from the grinding.

I have to agree with Randy, weld inbetween the brass but stay away from it as it can containment the weld you are making with the mig. Dont melt it out grind it out and grind only small areas at once, move around to avoid warpage.

I have been in the bodyshop business for over 30 years and brazing used to be the correct way to put panels on. It works very well on non unibody cars. The biggest mistake most people made when welding panels is that they didn't weld every inch and I mean not even a pinhole can be left and most importantly you need to sandblast the brazed area after you are done to removed the acids, rosins, etc. If you do this, your weld will last a very long time. If it were my car, I would not mig weld or glue it. If you had a fresh panel then those methods would be the way to go. Hope this helps and remember, it's just my opinion after 30 plus years.