Granite I can only work off of pictures you've sent, but this is what I was thinking:



The black being the metal you're leaving, the brown the rusted out area and the red the piece welded in. With some heat it be able to form that curve pretty easy.

 

your drip rail looks like what i had. cut everything out and make your own patch then decide if your going with a new drip rail or something else. i used 3/8 round stock to make mine.

 

Man, I don't envy you...I am sure you know, but with all that welding make sure you go slow so you don't warp the roof by the time you are done.
So, are you going to just cover up the lower layers of rust? How are you going to get all that out of that pocket so it doesn't rear it's head later? If you cut too much out of there I think it may mess up how the drip rail is sandwiched in there...maybe not?
Good luck! Show us what you end up doing.

My rails are bent up and rusted so I am shaving them off.

 

I cut out the really bad stuff underneith and cleaned up the rest with a wirewheel and then threw some rustoleum on it for now.



More to come, after I figure out how I want to make these panels.

Ben

 

It might not be 100% correct but I would weld a strip over the rot and float the seam with minimum filler. If you try to but it up you are going to have to use filler anyway and its going to take you twice as long. Just my two cents though.

 

I've done a pretty fair amount of body work, and I'm not a Metal Forming expert or anything--some people are-I'm not, but I've made this type repair and each specific situation has alway been different, and thus hard to plan.

In principle I just get in there and cut out the cancer and then see what's left, if its really bad you might find a source of patch panels from a discarded roof or cab etc, but this kinda rust I'm seeing in your pictures can sometimes spread out quite a bit.

And I think the biggest problem with that is one cant weld new metal to rust, so you have to keep removing until you get to something good.
I don't mind sealing "some" rust in an area that I don't want to disturb and that I think will be stable over time with some of the new rust stableizer chemicals and such. I've had pretty good look with them so far.

I think-you'll be able to do this just fine. You just first need to remove all the rust and see what you've got. Secondly with either a sheet of 18 or 20 gauge sheet metal you can form something good enough to weld in as you go--as long as the outside roof edge is still somewhat structurally intact we're just talking cosmetics. In general plastic fillers aren't waterproof and some of the new ones claim to be, but I like plastic fillers and have used them successfully for decades with little or no problem. I especially like the Evercoat Short Strand Fiberglass filler in the red cans, and also I use the Evercoat Kitty Hair Long Strand(states to be waterproof is it?). I mostly use the short strand.

I don't have a 56 etc so I'm not certain how much interior metal is in your way, but once I chopped a top in a truck with an entire second layer of metal on the inside, and this can be a problem. I'd sugget you consider taking a air cut off wheel or whatever to this entire area from the inside and remove one big piece(carefully) so that when your finished you can just "patch this now removed piece back in place". Getting to the inside of this area from the outside etc might be a big hassle. Just guessing. You'll have your hands on it and will know best.

I've successfully totally removed drip rails at least sections when I needed to and just found some little ready made 1/4 angle metal etc at the hardware store and made new ones. You can always add that later.

Just go slow and think. You'll do fine.

Good luck Tomget

 

I may be crazy, but how's about taking an inch off the whole top skin, weld it back on and end up with a lower roof line?!?!?!?

 

Boy, after looking at those pics are you sure you don't want to find another cab or at least a donor roof in better shape? You are in for a ton of work and dealing with still having a lot of interior rust unresolved. Just my opinion and good luck with it.

 

I have already replaced the cab corners and installed bear claw latches on teh doors/door jambs. I spent way to much time on this cab to get a different one now.

I got one piece in today 18ga . I have found a way I will get this to work without too much pain.

i am notching relief cuts int he roof line above where I cut out, so that I can change the angle of the line to the drip rail. Now it comes directly behind the drip rail and looks pretty decent. This is just the first piece.

 

Does the drip rail removal easy? Is there just grinding or do you have to weld as well? Sorry for the hijack!

 

You end up having to weld as well. Check out RandyJack's gallery, he did a great job at it.

Ben

 

You don't need another cab, just another roof. I would find a cab with a good roof and cut it in the front at the A-pillars and across the back along the body seam. Much less work than what you are currently attempting. I am not sure about the availability of slant cabs in your area but I would think that you could find one fairly easily that's been discarded because of a rotted floor or other lower body damage.

 

I have a roof section i saved from a cab!

 

create-

I did exactly what you are doing to a '56 cab years ago. I ended up with some smaller wedge-shaped pieces for the curves. It will work and will come out better than you might expect. It will take quite a bit of time and effort and is not 100% foolproof, but it's better than tossing the cab out.

If it will be garage kept, it will last a long time. I found the best way to slow the rusting process when you are done is to drive it every day and keep the water from collecting. (Unless you live in road salt country.)

Good luck.

Ryan

 

Thanks Ryan.

Actually, I am about 3/4th the way done with tack welding everything in. I will get some pictures tonight after a bit more work . It is actually turning out a lot better than I expected.

Ben