Rust repair questions 71 Challenger

[glovemeister]

Been working on the project recently. I chipped all the Bondo out of the rear quarter to roof seam. Had to be 1/8"-1/4" thick. I plan to sand out the seam and past it a bit.
 Wipe with metal cleaner, then use weld through primer. Any suggestions on that? Will be sitting for a few months.

Then lay some flat bar in it and fully weld it, 1/8" thick ok? Following this Iwill use epoxy primer. What filler should I use for this seam?

Lastly, I discovered a rust hole in the rear quarter, behind drivers wheel. Of course was bondoed over...

Same for rear window channel corners.

What gauge of sheet metal should I be using for general repairs like this? Lastly, is weld through primer on patches always a good idea, or just go metal to metal if I am welding it straight away?

Thanks guys
 

[Edison1970]

I just finished my roof seams.  I welded them completely across.  You can weld in a bridge between the two.  My only concern was warping the metal.  Some have filled it like the factory with lead afterwards.  I did mine with Duraglass mainly because I had success doing it this way before and also my funds have been limited to purchase the tools and the lead.  Weld through primer works.  Just a pain because the mig doesn't like it as much as clean steel.  I had to turn up the heat on mine to get it to burn through it good.  Might have also been the brand I used.  Bought it at Napa.

[glovemeister]

I just finished my roof seams.  I welded them completely across.  You can weld in a bridge between the two.  My only concern was warping the metal.  Some have filled it like the factory with lead afterwards.  I did mine with Duraglass mainly because I had success doing it this way before and also my funds have been limited to purchase the tools and the lead.  Weld through primer works.  Just a pain because the mig doesn't like it as much as clean steel.  I had to turn up the heat on mine to get it to burn through it good.  Might have also been the brand I used.  Bought it at Napa.

Appreciate the response. I was thinking that I would clean it real good, stitch it in a few spots down the channel lay the bar in and stich it until the seam is solid then weld that.  Followed by some sort of flexible filler.

You guys would laugh at the bondo I got out of there. I swear one section is at least 3/8th deep. No clue how far it extends up the roof/down the quarter. I'd guess a ways. Sure hope they feathered it and its not all beat up under there.

[jimynick]

For basic body repairs the usual gauge is 22, but 20 will last longer, but is a bit harder to cut/form, not overly so though. The factory only stitched the 1/4-roof seams and then soldered them. That is still the best, although not the only, way to do them. As for bondo, 3/8" was fairly mild. I've run into it where it was over an inch and lots of it, so don't feel too depressed about it. If you keep the flexation and water exposure down, it's amazing how long old mud will last. Have fun!

[glovemeister]

For basic body repairs the usual gauge is 22, but 20 will last longer, but is a bit harder to cut/form, not overly so though. The factory only stitched the 1/4-roof seams and then soldered them. That is still the best, although not the only, way to do them. As for bondo, 3/8" was fairly mild. I've run into it where it was over an inch and lots of it, so don't feel too depressed about it. If you keep the flexation and water exposure down, it's amazing how long old mud will last. Have fun!

Appreciate the reply.
Sanded out the quarter seams, after 3 hours of work today. Finally got the bondo backed away and down to clean metal.

Discovered drivers side wasn't really bad. Pass side has a fracture in the roof metal, a few holes, and a couple of dents.

Will post up some pics.

Will port

[glovemeister]

Hi everyone. I've been taking some pics as I go along, both for a restoration file and also so I can get some assistance on fixing the problems I have.  My primary goal is to avoid using filler whenever possible. Would also prefer to fix original sheet metal, instead of replacing it with new panels. In most cases it is way too nice to use new panels.

I've discovered the passenger side door has a lot of filler on it, as well as a lot of pin holes where a slide hammer was used. I've not got it down to metal to see what I am dealing with yet. Not a big deal given that the drivers door is the same.

My main concern is the passenger side quarter to roof seam. It is rusted through near the drip rail area. Also there are two dents right at or below the seam area. What is my best plan of attack for these? I felt around behind and can't really get to them with a hammer and dolly. They are visible in the last pic.

 I plan on cutting a piece out, my concern is how I flange it for the quarter seam as well as making sure I get the right curvature/shape on the metal.

Here are a few pics:

[Edison1970]

What you might be concerned with is the frame structure behind the seam of the quarter to the roof.  Mine had the rust issue like yours and when I cut it open, I had considerable amount of rust behind it.  Since you have to patch that area anyway, I would cut it open and see what it looks like.  There is another member here parting out a challenger that you might be able to get some of that structure if needed.

[glovemeister]

Thanks for the reply. I plan to cut out a section of it, as small as I can. I'll need to anyway for replacement sake.

Is it possible to get the patch panel with a nice curvature, running to the seam like the existing metal, or will it be a job for filler? It seems like a hard patch to make. It doesn't have a lot of curve, but its not flat either.

As far as the dent at the quarter seam, what is the best method for attacking those? I'm thinking hammer and dolly, but the only trick will be cutting the inner structure to get to them.

[Edison1970]

I might have a piece of the sail panel of the 1/4 I cut off.  If you need it let me know.  Just pay the shipping and it's yours.  I'm out of town right now but I'll check for you when I get back on Tuesday if you're interested.

[glovemeister]

Would really appreciate it!

[Edison1970]

this is what I found in my scrap pile.  Not sure it will work for you.  If I recall, I made that piece that you are going to cut out.  It wasn't that hard to make.  Let me know if this is going to help you.  Like I said, you can have it if you think you can make something of it.

[glovemeister]

I'll take it let me know how much and how to pay you.

[Edison1970]

let me find a box it will fit in and I'll get back to you.

[glovemeister]

Any luck with that?

[Edison1970]

Sorry.  Haven't had a chance.  I am putting it in the car now and I will get a box tomorrow.  I'll stop at the post office on my lunch hour to get the postage amount.  I'll need you address.  PM it to me.