Factory lap seam on new quarter panels

[Arrowhead]

I just got in two new quarter panels for the '57 I'm working on. They are for a coupe so they have the complete rear window frame and post. According to Woody's, the manufacturer has to make them in two pieces (you can see the vertical seam over the wheel opening). They are too big to stamp in one piece in their press because of the rear window frame. So they flange the seam between the two pieces and spot weld. The alignment is very good and a little filler would smooth it right over. I'm kind of concerned that the seam might telegraph through the paint (black). The only upside is a good portion of the seam will be covered by the side trim panels as it's Bel Air. I could attempt to slice out the seam and butt weld in a 2" filler strip, but I'm not sure it would turn out any better. Is there a cause for concern here or am I just over thinking it? And yes, it is going to be a show car.

 

[MX442]

I'm no pro here, but if it was my car, I would want it cut out and properly welded. Or, find a different panel.

 

[Chad.S]

Ikes.. that seam has to go.

 

[chevman]

There is good news if you decide to remove the seam---its 18ga instead of the original 20ga

 

[metalman]

There is good news if you decide to remove the seam---its 18ga instead of the original 20ga

I thought original for that era was 19 gauge. No matter, 18 gauge is thicker.
Charts vary, here's what I have: 20 = .0359", 19 = .0418", 18 = .0478" Often when I buy metal it's .002"-.003" or so under in thickness. Kind of like the big recess on the bottom of to-go coffee cups.

 

[chevman]

Rocker panels, roofs, and some inner parts are 19ga, but the doors, fenders, and 1/4s, are 20ga.

 

[Outlaw]

Another perfect fitment cut and butt weld project.

 

[metalman]

Rocker panels, roofs, and some inner parts are 19ga, but the doors, fenders, and 1/4s, are 20ga.

Good to know. I like working with the 19 gauge, hard to find local but I can get it from Wray Schelin.

 

[MP&C]

It's a wonder GM was able to make them in one piece..


Are the overseas reproductions made it one piece?

 

[carolinacustoms]

You could use filler rod to fill the gap in the seam and weld the front, then grind the front and back smooth removing the lap joint in the process, That would ensure the panels stay in shape but that would take near an eternity to do without warping them. If you can't buy the sedan quarters without the seam, I would use hard top quarters and leave the factory window frame in place, I have always cut the frame off of the sedan quarters anyway and butt welded at the body line on each end of the window. Just my opinion

 

[Bob Hollinshead]

That lapped seam has to go for sure, or it will show itself with changes in temperature.

 

[DATEC]

Agree with both Carolinacustoms and Bob. But welding the lower window frame area would also help restrict the warping with the strength of the roll in the quarter, it would have been nice if they put it there instead.

Since you have these I would remove the flange and save it for filler when butting the 2 half's back together that way atleast you are using the exact same metal as the rest of the quarter.

 

[chevman]

What ever you do, its going to require some welding, because the hard top 1/4 has a different dip under the side window than the sedan, so to use it you have to keep the sedan dip and weld the HT 1/4 around it. Might as well just butt weld the sedan panels.

 

[carolinacustoms]

Thanks for that information Chevman, I never knew the body lines were different from the hard top to the sedan. I knew all of the glass was different, but never knew the "dip" was different. My apologies for offering a bad solution to the OP, in recommending the use of a HT quarter

Kelly.

 

[crashtech]

You could use filler rod to fill the gap in the seam and weld the front, then grind the front and back smooth removing the lap joint in the process, That would ensure the panels stay in shape but that would take near an eternity to do without warping them.

I might try a variation on this theme, cutting small sections of the overlap out, planishing til flat, weld, planish some more. Repeat until the overlapped area is gone.

 

[Outlaw]

That lapped seam has to go for sure, or it will show itself with changes in temperature.

Bob, I have never had a real good understanding of lapped seams and ghosting. Earlier cars and trucks had over lapped seams filled with lead. I painted a few of them and never had issues with ghosting over seams that were overlapped and leaded. Those seams consisted of a double layer of sheet metal and lead over that. A common area was in the 60's mussle cars where the roof met the rear and side window sheet metal. I am not questioning whether or not repeating this process today will have a ghosting affect. Im just wondering why. Is it anything to do with removing all the bad (good) stuff from the paint we used back then?

 

[chevman]

I

He might not want to keep it aligned the way it is now, because it looks like there might be a significant difference across the seam---level wise.

 

[Bob Hollinshead]

Bob, I have never had a real good understanding of lapped seams and ghosting. Earlier cars and trucks had over lapped seams filled with lead. I painted a few of them and never had issues with ghosting over seams that were overlapped and leaded. Those seams consisted of a double layer of sheet metal and lead over that. A common area was in the 60's mussle cars where the roof met the rear and side window sheet metal. I am not questioning whether or not repeating this process today will have a ghosting affect. Im just wondering why. Is it anything to do with removing all the bad (good) stuff from the paint we used back then?

JMO-but factory seams like on a sail panel that are filled with solder didn't ghost much because that is usually a strong area with a good amount of shape and the strength of the solder helps-maybe it's the way solder absorbs heat or conducts it more evenly? If you've got a thick area of metal surrounded by thinner sheetmetal and all the heat is being absorbed and conducted from the sun the thicker area will radiate a larger amount of heat and expand any fillers or coatings more in that area. Do a lapped seam in a large area like that quarter and it will likely show, I lapped a lot of half quarters years ago and they would usually show their seam when they warmed up in the sun-not everyone notices though. The worst one I ever seen was done by someone else on a 67 camaro convert I redid-it had been flanged and spotwelded along the top edge of a half quarter with about 1" spacing between welds then finished with filler. That quarter showed every one of those spotwelds and also the seam edge whenever it was in the sun LOL. I cut through both panels and butt welded it and the ghosting went away.

 

[Outlaw]

Thanks Bob, I never had any doubt there is an issue. I just needed more information to undersrand why, Thanks again for explaining it in more detail. One thing I would never do is spot weld and fill with filler. If I spot weld, its going to get seam sealer. I would have been afraid the filler would have cracked in between one inch spot welds.