Rear quarter panel to roof joint?

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Joined
May 15, 2011
Messages
3,536
Reaction score
445
Location
PA
My Car
1971 Mach 1 Mustang
Anyone have any pics of the roof panel to quarter panel seam? I am going to be installing new quarter panel on a guys 71 mach 1. Just want to see what the seam looks like before I get into it.

I know they are leaded in from the factory. Can I just sand the body down to the bare steel then use a torch and carefully melt away the lead? Also what is the best product to use to replace the lead? Im sure you don't want to use just standard body filler. UPOL fiberal?? All-metal filler? Or should I go old school and re-lead the seam? or is it possible to weld the seam solid and use a lightweight filler over the weld? Let me know what you guys think!

Thanks

 
Last edited by a moderator:
I think the All-Metal would be a good choice, but you'll probably need to follow it up with some regular filler or USC Icing just to make sure it's 100% smoothed out before primer and color.

I also think I remember Scott (Qcode351mach) welding the seam 100%, rather than just spot-welding it - to ensure no shifting after everything's done (which could literally pop the filler right out).

I know the seams on the A-pillars of mine wer filled by the body guy/painter using God-Knows-What, and it's apparent to me they didn't do their best work - they just left the lead in the quarter/roof seams, and skinned over with filler. I can't wait for that repair to start showing itself. In fact, I'm getting pretty tired of discovering new 'features' in my paint job the more [closely] I look at it. You would think that $5500 would've gotten me a pretty good paintjob, considering they didn't really have any major body work (aside from blending the wavy quarter skins) to do. Oh well - I already have a new painter in mind for the 'next paint job' [when this one finally starts visibly going south).

Just my two cents... and I'm not a body guy by any means.

 
I torched out the lead then seam welded the whole thing, then epoxy primered , then used short strand fiberglass filler. Worked out pretty good, I had a donor roof I put on and also put in a patch from the donor roof just below the seam line. There was a lot of grinding and cleaning up after this picture. 20151105_182403.jpg

 
Last edited by a moderator:
Melt out lead with propane torch--weld seam shut the entire length especially into the quarter window area--epoxy prime--upol fiberal--then skim coat body filler.

Thats a known weak spot on our cars and I've seen plenty with stress cracks at that joint, also where it meets the quarter window and the rear window channel.

P.S don't use all metal that stuff is the worst !!!

 
Melt out lead with propane torch--weld seam shut the entire length especially into the quarter window area--epoxy prime--upol fiberal--then skim coat body filler.

Thats a known weak spot on our cars and I've seen plenty with stress cracks at that joint, also where it meets the quarter window and the rear window channel.

P.S don't use all metal that stuff is the worst !!!
Thanks Q and everyone for the replies. I will be doing just as you said Q. I know my car has cracks in the paint at the roof joint and corner by window.

The car im doing is a bone stock 351 2v. It has held up pretty good over the years but definitely needs atleast 1 new quarter panel. Once I get started on this car I will start a build thread and keep it updated. I will be restoring it over the winter.

 
Last edited by a moderator:
Melt out lead with propane torch--weld seam shut the entire length especially into the quarter window area--epoxy prime--upol fiberal--then skim coat body filler.

Thats a known weak spot on our cars and I've seen plenty with stress cracks at that joint, also where it meets the quarter window and the rear window channel.

P.S don't use all metal that stuff is the worst !!!
I knew Scott would provide the best information.

Good to know on the All-Metal. The body guy I mentioned asked for a can of that and explained what he was going to do with it - seemed to make sense to me... to which I picked it up and provided ($100/can - sheesh). Then I discovered he'd never even cracked the seal on it by the time I got my car back, and consequently hadn't used it where he said he was going to, either... and never offered to give it back, either. Guess I got screwed on that one, but at that point I honestly didn't care since the car was shiny again. :shootself:

 
I used the 3M Panel Adhesive on my quarter skin replacement when I re-installed it (after messing up the first one).

That stuff is awesome! However, I have no idea how it would go on the major attachment point like that. I've heard it's as strong as welding, but I don't have any experience with it beyond sticking my quarter skin replacement back on. I don't see why it couldn't be used.

I'd wait until Scott weighs-in before making a final decision, if possible.

 
What about the idea of fabricating a piece of steel to fill the gap and entirely welding it in?

Was it originally designed to be a flexible point?

Sent from my SM-N920V using Tapatalk
I was thinking the same thing. Weld the seam solid, then fabricate a piece to fill the gap and weld it into place. Then skim light coat of mud over it.

 
Last edited by a moderator:
ajrm8j.jpg


Here's one.

BOSS 351

 
What about the idea of fabricating a piece of steel to fill the gap and entirely welding it in?

Was it originally designed to be a flexible point?

Sent from my SM-N920V using Tapatalk
I was thinking the same thing. Weld the seam solid, then fabricate a piece to fill the gap and weld it into place. Then skim light coat of mud over it.
You could do that it's just a lot of extra work. No a roof to quarter panel joint isn't designed to flex

 
On the panel adhesive. My friend that does restores had a customer come to him with a camaro that the door was just not fitting right. He had only had the car about 6 months paid big money for it. It turned out that all the body replacement panels had been installed using adhesive and was coming apart. Don' have any idea of the brand. When the factory uses adhesive there are also other mechanical connections involved especially when the area is under stress. Tog-L-Loc invented the process, http://www.btmcorp.com/tog-l-loc.html

I think Ford uses this process on some of the Aluminum on the F-150. I know that BMW did on the front shock tower joints. Aluminum casting joined to Steel Stamping with adhesive between. They also sometimes spot weld. No adhesive joint is safe for our type cars not designed for it. Always weld.

 
I highly recommend doing this with the power you are running. You can see the gaps mine had between the welds.
Mike thanks for the up close pics, that's what I was looking for. This isn't for my car though, its for a guy that I'm doing some work for. But I will still be welding it up solid.

 
I highly recommend doing this with the power you are running. You can see the gaps mine had between the welds.
Mike thanks for the up close pics, that's what I was looking for. This isn't for my car though, its for a guy that I'm doing some work for. But I will still be welding it up solid.
Your Welcome Kevin.

 
Back
Top