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the best place to put quarter skin seam

25K views 93 replies 12 participants last post by  123pugsy 
#1 ·
Hey all you radical dudes.

First things first. I've done a lot of reading, and have searched through the old threads on this board for quarter skins. I don't want to be That Guy that asks the same redundant question again. So if you are already aware of a good thread that answers this question, don't feel like you have to waste your time answering it yet again, just link me.

Now on to the business...

I have some aweful damage concealed with 1/2" of filler on the pass. side quarter. It's not repairable and the panel is so friendly you could probably get sex from it if you stood close enough (perhaps I should start standing closer).

I had a nightmare in replacing the full quarter on the driver's...so much that I gave up and took it in. Also replaced the tail light panel.

I want to try a skin on the pass side. I have a nice MIG that I'm decent with, not a pro, but not a beginner. I also will butt weld the panel in, not over lap. I also have an ever growing collection of body tools and some formal education on body work from the local tech school because I wanted to help my hobby.

I've read on Mustang Monthly that they put the seam on the top surface ( that is, the area between the body line and the trunk lid) rather than on the side of the car. It seems this would be much easier to conceal too, than a seam on the side of the car.

What have your experiences been? Thanks in advance. You guys are a cool bunch of dudes!
 
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#2 ·
When I have replaced quarter skins I have always spliced them in just below the top style line, not sure what year mustang you are working with but if it's a 60's era car then the quarter has that sharp peak on the outer top edge. That peak provides a lot of strength and I would splice in 3/8 to 1/2 inch below that peak (on the outside) if I were doing the job.

You could also do an overlap seam at the top of the quarter and it would be easy to hide. With an overlap I would cut 3/4 to 1 inch below the top and overlap 3/8 inch.

I would be curious to hear if anyone has a different opinion on the best place to splice and why.
 
#3 ·
I'm with you Hemi, however going up over the top would be a nicer look on the inside. The problem I have with going over the top is will have to pull down the original upper section a little so your quarter isn't too high. But honestly I think it's six one, half a dozen the other. :D

Brian
 
#4 ·
After looking at the contour of the car more, I can't see how I want the seam to be on the top. I'd rather prefer to do a buttweld rather than an overlap, and I think I've got a good strategy to do it.

I need to wait for the next sale to buy the panel but I'm excited to start. The problem is I'm always excited to start this stuff in thinking about it, and it usually turns to hell within a matter of only a few hours. :evil:
 
#5 ·
I replaced a lot of these panels back in the day and I always lap welded just a1/2 to 1 in below the upper body line. I would trim off the old 1/4 panel at door post and butt weld just the frist in" or 2 right at the door opening so You dont end up with a door fit problem. Same goes for camaros.
 
#6 ·
swvalcon said:
I replaced a lot of these panels back in the day and I always lap welded just a1/2 to 1 in below the upper body line. I would trim off the old 1/4 panel at door post and butt weld just the frist in" or 2 right at the door opening so You dont end up with a door fit problem. Same goes for camaros.

Yep, it works like a dream. As far as Butt welding it, yes you can but it will add quite a bit of difficulty to the project. What is the overall expectation of the car? What is the condition of the rest of the car?

Don't let people scare you with the whole flange weld seams are a place for rust to start BS, the ENTIRE CAR is held together with these style welds! EVERY SINGLE SEAM on the ENTIRE CAR is a flange, lap style weld! One more isn't a big deal.

But yes, if this is a special car and you want it extra nice, a butt weld would be the way to go.

Brian
 
#7 ·
A full panel is always the way to go if possible, its less work and less filler and makes for a nicer job (less places to work body filler) IMO. If you must splice the panel I totally agree with using a body line for strength so there's less warping. Good luck with your project.
 
#8 · (Edited)
Lizer said:
After looking at the contour of the car more, I can't see how I want the seam to be on the top. I'd rather prefer to do a buttweld rather than an overlap, and I think I've got a good strategy to do it.

I need to wait for the next sale to buy the panel but I'm excited to start. The problem is I'm always excited to start this stuff in thinking about it, and it usually turns to hell within a matter of only a few hours. :evil:

If you're going to butt weld it, you'll have to learn to take out the shrink that comes with the welding.
You'll also need to learn how to use a shrinking disc.

If in a couple hours things turn to stink, these are the two things you will need to understand and learn to get you out of trouble.

Pick up a couple of scrap pieces of sheet metal and weld them together by tacking only with the mig.
After they cool, you'll have to hammer on dolly to stretch all the shrunken metal out. When you do this, you will overstretch somewhere for sure. This is where the shrinking disc comes on.

Without learning this basic welding, stretching, shrinking, you will be exactly in the same spot you've been in before once again
no matter where you put the weld seam.

These 1'' welds were done and then the weld was stretched back to where it started with hammer on dolly. I did 1'' at a time so I knew where the warping problem came from.



 
#9 ·
MARTINSR said:
Yep, it works like a dream. As far as Butt welding it, yes you can but it will add quite a bit of difficulty to the project. What is the overall expectation of the car? What is the condition of the rest of the car?

Don't let people scare you with the whole flange weld seams are a place for rust to start BS, the ENTIRE CAR is held together with these style welds! EVERY SINGLE SEAM on the ENTIRE CAR is a flange, lap style weld! One more isn't a big deal.

But yes, if this is a special car and you want it extra nice, a butt weld would be the way to go.

Brian
ok, you've got my attention.

The overall expectation of the car is to make it the nicest car I can, minimizing as many short cuts as possible and doing everything as right as possible. This also meant the floor pan was butt welded in rather than lap welded. The rest of the car is in good shape; the full left quarter has already been replaced, as well as the tail light panel. I've completely restored the front, and am using the original fenders.

If you flange lap weld, do you just do a series of plug welds? I've heard that the flanger will cause some distortion in the metal in areas where the body line curves, such as the area immediately beneath the quarter window on the Mustangs.

I don't want to do a full quarter again because getting everything aligned was such a pain. Of course since I haven't done a skin yet it's easy for me to say it will be easier.

Will you still get extensive shrinking that will need to be addressed even after doing a series of many small tack welds, hopping around the panel and allowing for natural cooling?

I don't notice a lot of distortion on the other things I weld (I do patch repairs as butt welds as well), but I've never had to do a long run on a big flat panel like this. And that is a very long ways to make a lot of tack welds.
 
#10 ·
I actually have the same question so I hope the OP won't mind me piggybacking on his question. I will say that my original preference in the past had been to butt weld in a quarter skin (full quarters are not available for my car). I've found it exceedingly difficulty to butt weld a seam and not have the seam pucker inward as the metal cools/shrinks. As previously mentioned you can get a nice result by hammer/dolly to stretch the shrinked metal back into shape. The problem I found is in quarter panel seams that extend forward of the wheel well. There's really no way to get behind the panel so therefore the seam can't be planished. I guess you just fill it in with filler.

Next time I do a skin, I'm gonna try lap welding. Not knowing much about, can anyone give us the basics. I assume that when you cut the original quarter out, you leave extra metal for the overlap. Flange the original metal with a pneumatic flanging tool. Is the skin held on just with a series of plug welds? How close should they be together? Then just finish with filler of choice?

Thanks
 
#11 ·
If you have done the rest all in butt welds you are pretty well versed in them and should be able to continue and use a butt weld here. It sounds like you are doing a kick but restoration and it sounds like the car deserves more of the same. :D

You do NOT just plug weld along the flange seam, You still need to completely weld the seam or you WILL have "ghost" lines once you are all done with body and paint. A quality flange tool like I bought at Eastwood years ago (made from real American made ViceGrips) does a hell of a job with little distortion.


Personally I say forget the pneumatic flanger, as well as the pneumatic hole punch, i have preached here enough why I dislike them. But hand tools are almost always better, with very few exceptions, than pneumatic tools.

If you keep your welds small and ALLOW THEM TO COOL NATURALLY you can keep warpage down to a very small amount or not at all. If you cool them with air or water or something you WILL have warpage.

Brian
 
#13 ·
I see that a lot,....going the full panel route. And I've already been that route on the driver's side. I ended up giving up and taking it in, but I was also replacing the tail light panel too. Just too many places not lining up right. I've never done a skin yet, but it's less places to have to line up. I can get a skin on sale for $83 with free shipping. It only cost me $50 after kicking in a gift card (I bought the skin today), so I'm out little if I trash the skin. Which, by the way, I don't intend to do.

Since the full weld still has to be made along the entire flange joint, I would assume it's not as prone to warpage since you're welding over a lot more metal at this point, as opposed to a butt junction?

Someone feel free to add recommendations or corrections to my strategy...

1. Carefully remove spot welds from all the necessary areas (door jamb, wheel house, tail light panel). I grind the spot welds out to keep the original mating surface intact.

2. Cut old panel out 2-3" below body line.

3. Tape along body line on new panel and cut about 1" below the line. The tape is spacer to maintain consistent distance. I might use a plasma cutter to make this cut so it's nice and clean.

4. Fit new panel and screw in place in door jamb, tail lamp panel, and wheel house.

5. Scribe along old panel where new panel meets it.

6. At this point I can attempt a flange seam, and if I bomb it I still have enough metal to go butt weld. Remove new panel.

7. Cut excess off old panel so the distance from the scribe line to the cut is the depth of the flanger throat.

8. Punch holes in new panel and reinstall. Plug welds every 6 inches? And then close the seam junction with hop scotched tack welds, allowing natural cooling. This means it'd probably take multiple attempts over the course of multiple days before I get the entire seam welded continuously.

The thing with my butt welds is they were never the prettiest, but they never had to be. They were always in inconspicuous areas where it didn't really matter. This is scary to me though :pain:
 
#14 ·
ooh I just thought of something else.

When I make the initial cut in the old metal, 2-3" down from the body line. If I just make that cut first, and leave the rest of the panel still attached (or screw it back if I already removed spot welds), is there any reason I can't put in my panel clamps and butt weld the old panel back together to practice my weld?
 
#16 ·
The only change I would make to your plan is in #8 where you plan to punch and plug weld the panel prior to stitch welding the top seam. Instead of plug welds I would temporarily screw the panel together at the flange, this way you avoid any disortion from the plug welds. Once the panel is welded you remove the screws and weld up the holes.
 
#17 ·
Lizer said:
ooh I just thought of something else.

When I make the initial cut in the old metal, 2-3" down from the body line. If I just make that cut first, and leave the rest of the panel still attached (or screw it back if I already removed spot welds), is there any reason I can't put in my panel clamps and butt weld the old panel back together to practice my weld?

I don't advise this.

Get some scrap metal or just take off the scrap piece off the car, cut that and practice on it. This is a good way to try a butt weld and try to planish out the shrinkage. If you learn this, you'll never be in doubt again.
 
#18 ·
When I suggested a full panel I was referring to ones that installs like the original and not a half panel. Sometimes the half panels are all you can get so that's what you have to use, but I believe you are working on a Mustang so full panels should be available. Full panels are a lot more expensive but well worth it because they save time and you will have less body filler and in the end a lot nicer job. Most of those splice panels (especially the cheaper ones) are very poorly made and are warped and distorted when you get them. Opinions vary and I'm sure you will do whats best for you and do a good job. I run a small body shop so saving time and using good quality parts saves money for me and gives my customer a better job. Good luck on your project!
 
#19 ·
39Hemi said:
The only change I would make to your plan is in #8 where you plan to punch and plug weld the panel prior to stitch welding the top seam. Instead of plug welds I would temporarily screw the panel together at the flange, this way you avoid any disortion from the plug welds. Once the panel is welded you remove the screws and weld up the holes.
You're right, that is a better way to go.

Brian
 
#20 ·
rwa1015 said:
When I suggested a full panel I was referring to ones that installs like the original and not a half panel. Sometimes the half panels are all you can get so that's what you have to use, but I believe you are working on a Mustang so full panels should be available. Full panels are a lot more expensive but well worth it because they save time and you will have less body filler and in the end a lot nicer job. Most of those splice panels (especially the cheaper ones) are very poorly made and are warped and distorted when you get them. Opinions vary and I'm sure you will do whats best for you and do a good job. I run a small body shop so saving time and using good quality parts saves money for me and gives my customer a better job. Good luck on your project!
X2. I will add that I've seen too many cars where the weld seam for the partial panel shows up once the car is parked in the sun and the metal starts expanding. If you can get full quarters, use them. The partial quarters are inexpensive for a reason.
 
#21 ·
Now I have never done a full repro quarter let me first say that. But I would doubt they fit any better than any other repro part like a fender which is usually pretty bad. A complete OEM quarter, God yes they are MUCH easier than doing some splice job (other than a pillar splice of course) but an aftermarket? Man, I have to wonder just how bad of fit they are and doing the partial quarter would have to be easier.

Brian
 
#22 ·
The driver's side was a full quarter replacement. It was a horrendous pain to get it all to fit. I think I mentioned it earlier, I ended up giving up after fighting it all winter and took it into an amazing body shop in my town who did an amazing job putting it in. In the end I'm glad I did because I learned a lot in seeing what they did. I had to do the entire quarter because it had been all hacked up previously.

The passenger's quarter is not all hacked up, only has some serious body damage. I have more confidence in my welds than my ability to make a good fit. But I may be oversimplifying it. I'm almost positive I am. I also thought the full quarter install wouldn't be too bad.

The skins are made of the same metal, and even in the same presses as the full quarters. The reason they are more expensive is partly because there's a little more metal, but it takes a lot more time to make the full quarter. Several other parts have to be spot welded in place, and the panels need to be removed from the die in order to make the other bends. It's a more involved manufacturing process which means more $$$. At any rate, my Mustang supplier is always having big sales and they have free shipping on these, so cost isn't so much a factor on the parts I buy.

I'll practice a butt weld with the panel off the car then.

Every time I use reproduction sheet metal I do feel like I'm rolling the dice. I've lucked out thus far and the panels I've had (floor pan, full quarter, trunk lid, tail light panel, trunk extension, wheel house, strut support, battery tray and fender battery apron, front radiator support, rear trunk brace, door skin, front and rear valance) haven't been too aweful in terms of being dinged up or impossible to fit, though I might have to do some modification on nearly all of them, such as hog out a bolt hole to get it to line up properly, etc. Whenever I can opt to save or salvage the original panel I do. Original Ford tooling for the 67 Mustang model year is basically limited to hood, fenders, and front valance for sheet metal. There may be a few odds and ends but I think those are about the major parts.

Thanks all for the advice and comments thus far. It's a nice discussion. I do listen to and consider everything everybody tells me, and then weigh it against my abilities and goals. I've participated in threads before where the original poster is asking for help and advice and never follows anything that they're given. It's frustrating and in the end I chalk them up as an idiot and never help them again. I'll never be That Guy. If I really didn't want answers I wouldn't waste my time creating the thread in the first place.
 
#24 ·
Well the thing is if you screw it you have a lot more control. Just screw it, (I personally usually have enough Vicegrip C clamps to do the job and skip the screws, hardly ever use them) and then weld the seam.

Brian
 
#26 ·
I mentioned before that I couldn't seem to butt welded seams without having the seam shrink and suck inward. Is that a fact of life with welding thin sheet metal or is it my technique? (I am trying to cut the metal so that there is zero or very little gap although honestly I could have improved up on this part. I also am welding the seam as a series of tack welds, letting them cool. I am finishing the weld by grinding it down with the edge of a cutting wheel on a 4.5 in grinder with the wheel held at a 90 degree angle to the panel). Again, the reason I don't like this is because I can't access the back of the panel is certain parts and you are left filling this in with a coat of filler which I don't like (I'm sure it would be greater than 1/8 and perhaps closer to 1/4 inch at it's thickest point).

As mentioned above, with lap welding, I've heard that on some cars, you can see the seam even under paint in certain light. Any idea why this would be the case if the seam were fully welded?

Just as an experiment I might get one of those flanging tools and try welding a practice panel lap welded and one butt welded just to compare the amount of distortion I get.

Thanks again.
 
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