Rusted Roof Cavity Repair?

[rcalzadilla]

Help with finding a permanent or close to it, solution.
Have repaired this area twice but after about 1-1/2 yrs it comes back again.
Previously have cleaned rust, filled with caulking and shaped it, then painting with Rust-Oleum paint.
Suspect that regular caulking cures acidic and will rust.
https://i.postimg.cc/MKrtT74P/20191012-153917-HDR.jpg
https://i.postimg.cc/tJ8Z04S5/20191012-153949-HDR.jpg


Thanks

[NitroPT]

There is lots of rust that was not treated when you first did the repair. The rust continued under your first repair and became worse. No it may not be an east task to slow or stop it without cuting/grinding the rusted area out.
Be careful with what you use if oxygen is told sealed away from rust the rust will continue to increase under any repair you make.

[LionPT]

Fiberglass it or cut it out.

[chuzz]

Cut the roof off and weld on another one.

[ptprice]

My avocational hobby for over 60 was restoring vehicles. One at a time.
In every case rust had to be remove. The operative word being REMOVE.
A full body dip is preferred but in the case of your roof corner what you can't logically cut out must be similarly treated.
Eastman makes some fine liquid products. See attached.

In conjunction with or additionally, another repair adventure would be,
invest in an Eastman crimping tool, see attached, make a raid on your local salvage yard and with a battery powered saw or chisel and hammer, remove enough corner donor metal from a dead PT, put it in your pocket, cut it to shape back at the ranch, cut out the offending rusted corner, flange the edges and either spot weld, fiberglass, rivet or some combination, secure in place.
Finishing it will be the icing on the cake. That should make a permanent repair.

p16037-Rust-Dissolver.jpg

p16032-Black-Anti-Rust.jpg

21keDdSPYTL._AC_.jpg

[soonercruiser]

Hey!
SIMPLE...
Rustoleum makes spray rust treatment..."converter"agent!
Use that before any type of paint as prevention!
https://www.zoro.com/rust-oleum-rust...E&gclsrc=aw.ds

BTW...how are you addressing the rust underneath the metal in that area?
The "above" on a paint brush might help!

[NitroPT]

I use to restore BRITISH cars for a living!!!!!!!!!!!!!.... what a PIA.

None of the products that convert rust or supposedly STOP rust really work well in any area that there are lots of seasonal moisture.

In other words there are NO MAGIC chemicals. Rust is metal cancer and must be removed.

Some of the worst thing to use is anything that is Aerobic. That is pretty much all the chemicals. All they will do is slow down or mask the "CANCER" called rust.

If you are not experienced in advanced body repair this type of repair removing metal and re welding replacement parts is not advised. You will "frick" it up!
The investment in the proper and necessary tools is almost as much as simply paying a body shop to properly do the work.

Now if you intend to do other projects and maybe some on the side part time income to pay for your investment in the tools to undertake panel restoration replacement and repair then by all means give it a go!

[ptprice]

Originally Posted by NitroPT

I use to restore BRITISH cars for a living!!!!!!!!!!!!!.... what a PIA.

None of the products that convert rust or supposedly STOP rust really work well in any area that there are lots of seasonal moisture.

In other words there are NO MAGIC chemicals. Rust is metal cancer and must be removed.

Some of the worst thing to use is anything that is Aerobic. That is pretty much all the chemicals. All they will do is slow down or mask the "CANCER" called rust.

If you are not experienced in advanced body repair this type of repair removing metal and re welding replacement parts is not advised. You will "frick" it up!
The investment in the proper and necessary tools is almost as much as simply paying a body shop to properly do the work.

Now if you intend to do other projects and maybe some on the side part time income to pay for your investment in the tools to undertake panel restoration replacement and repair then by all means give it a go!

Blair flanging pliars, $21.99 from Summit Racing, with a pop rivet gun or two part adhesive would be small price to pay to install a replacement insert.
It's not a long list of shop tools as mentioned. Just a few supplies to install a rust free replacement for that rusted roof corner.
There are dedicated adhesives used to secure flanged joints eliminating rivets or spot welds on small projects like this.
It's not a quarter panel, just an inner roof corner. I've used flanging pliers on the smallest of replacement "panels". The flanged overlap makes a perfect fit if carefully planned and the insert remains at true surface level at the over lap joint.
Wanting a permanent, properly done, rust free repair? This is one way to replace the rusted metal!!!
Happy PTin', ptprice


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[Busted_PT]

First of all, pop rivits not a good choice. Will pop back through. But if you have no choice.

In your particular case. Looks like you got the metal clean on the out side. But the reverse side looks like what you removed. It would be helpful if you could get some of those treatments in behind to slow as much as possible. Then coat the bare metal with it as well. Then instead if call, use Bondoglass. Use it just like regular bondo. It us harder and doesn't absorb moisture. Smith and prime and paint. This will last as good as cut and weld. Why you ask. When you weld a patch in you burn the metal on both sides. If you can't get to it to clean and prime, it's just going to rust again. Plus you will have to pain beyond the gutter because of the heat burning the paint. As you have it. You should be able to keep you work below the top edge.

By the way. Are you close to the ocean. Because I have not seen a cruiser rust there before. Cars around salt air rust in higher areas like yours has. Just curious.

[raeder]

Originally Posted by ptprice

My avocational hobby for over 60 was restoring vehicles. One at a time.
In every case rust had to be remove. The operative word being REMOVE.
A full body dip is preferred but in the case of your roof corner what you can't logically cut out must be similarly treated.
Eastman makes some fine liquid products. See attached.

In conjunction with or additionally, another repair adventure would be,
invest in an Eastman crimping tool, see attached, make a raid on your local salvage yard and with a battery powered saw or chisel and hammer, remove enough corner donor metal from a dead PT, put it in your pocket, cut it to shape back at the ranch, cut out the offending rusted corner, flange the edges and either spot weld, fiberglass, rivet or some combination, secure in place.
Finishing it will be the icing on the cake. That should make a permanent repair.

Attachment 31212

Attachment 31213

Attachment 31214

Ok we will give that a try for the T100 project.