Cab Roof Rusted Out at Drip Rail on Pass Side

[Hunter4x4]

Anyone here have their roof rust out above right above the drip rail on the pass side? I've heard that this is common with our style trucks, in fact, I've noticed on a number of other trucks myself.



Thought I just had some surface rust the other day and all off a sudden I've opened up a hole about 1/2"-3/4" wide and about 12"-15" long - like an ugly eye brow!! And I can see lot's of rusty metal on the inside of the roof - almost like the interior metal wasn't painted or primed at the factory.



The maddening part is that there isn't a speck of rust on the rest of the truck!!!



Any suggestions for the best way to fix this? Any short term quick fixes (other than blue duct tape!!). I'll listen to any and all suggestions!!!



Thanks!



Mike

 

[jaynes]

same problem

yo,



I have the same problem on my truck, except right on the drivers side, and not as large. It's getting large, thats the problem. The other problem is that my truck is up for sale, and I need to get that fixed pronto, without paying an arm and a leg. I would like some ideas on this as well!!



jaynes

 

[BHiggins]

My 1990 did the same thing, short of welding a new roof on I spread windshield urethane on it just so water would stay out of the cab and it wouldn't get worse (silicone won't stick to rust, urethane will). Not wanting to replace the entire cab (the rest of the cab was spotless), I priced having the roof sectioned at the upper seems and welding on a new roof and it seemed to me the best solution, not much body work to do when it's done at the seem so the price was pretty reasonable ($350. 00 - $400. 00 with paint). The only problem was I had to supply the new roof section. I found a "new" first gen though, and sold the old truck with the roof rusted.

Before anyone asks, yes the new owner was aware of the problem with the roof when he bought it. The truck had a Lund visor on it so even though it was "gooped" with urethane, you could hardly notice it unless you went looking.

 

[jaynes]

besides the replacing a section and the urethane, can you just put some naval jelly on it to get the rust off, grind and sand it, primer and paint it? It probably wont last long, will it? Is that a lost cause?



jaynes

 

["Mad Max"]

There is this stuff called POR-15, and it's what I use exclusively to stop and prevent rust. It lasts a long time, but it needs to be topcoated if it's under constant UV rays. You have to stop the rust, and this stuff is about as good a product as it gets. Use the metal-ready prep spray beforehand to prep the area - it kindof dissolves the rust and coats the area with zinc phosphate, then you top coat that with the POR-15, and yer pretty much done.

- Max

 

[Hunter4x4]

Sam - so after you POR15 it then what? Do I just lay a layer of fiberglass and filler over it and clean it up as much as possible and paint to match? I agree I have to stop the rust, but I also have to fix my roof!!



Regarding the rust treatment - I can see rust way inside the panel - can you spray this stuff?

 

["Mad Max"]

yeah you'll want to shoot the POR (reduced about 10% with their reducer) with like a HVLP jam gun. You cannot lay bondo over POR-15, but you can spread Marine Tex over it. Marine Tex is probably the most amazing 2-part 'mud' mix I've ever used, and it works great with POR-15. You can rebuild seams, window channels, whatever you want. You lay down the POR, let it get tacky (4 hours), and you can lay in some fiberglas cheese cloth to build up an area or repair a panel, then soak the cheese cloth with more POR, let it get hard, then mix the Marine Tex and spread over the cheese cloth to fill in the gaps. Once all that is dry spray epozy primer over everything - it sticks hard to POR and everything else, and is an awesome base for your top coat.

Also, if the rust has made the roof real thin you may want to buzz away the thin metal (ie - cut the rusty panel completely away) with a death wheel until you get to full thickness, then make a new panel and weld it in place. While that panel is out you can put the POR in there and shoot it as far inside as you can. After that the truck will probably last longer than you .

- Sam

 

[Hunter4x4]

Couple more questions:



Sam - I know a couple places I can get POR-15. I've never heard of 'Marine Tex'. Where can I get that? Is it a bondo/fiberglass filler type of stuff? And the 'epoxy primer' - is that a 2-part primer that I'd get in an auto body shop supply?



Sounds like you've done this before. After the Marine Tex hardens it sounds like you can sand/shape/grind it?





B. Higgens -

What's 'windshield urethane'?





Comments: Right now I'm leaning towards a backjyard fix and hiding it with a cab visor, but gawd, I don't like the looks of those things sometimes!! Anymore thoughts anyone?

 

[BHiggins]

Hunter,

Windshield urethane is a nasty gooey mess that goes between the metal and the glass when installing a new windshield. It's DEFINATELY not pretty, but it worked tp "fix" the leak and kept the rust from getting worse. As I said, I had a Lund visor on the truck so the urethane wasn't that noticeable, but it seems to me you want a more cosmetic fix than the one I did. Whatever you decide, don't wait long... mine went from some bubbling under the paint to full blown rot in less than a year. When I bought my "new" truck, I immediately sent it out to the body shop and had the whole roof gound down to the metal, re-primed and painted. The only rust was a very small spot on the outside of the drip-rail on the drivers side, but it's cheap insurance to keep it from happening to this truck.



Good luck,

Brian

 

["Mad Max"]

yeah I've had to do this kind of repair to a couple different vehicles, but never the same one twice. Marine Tex is incredible stuff - think of it as very heavy duty industrial bondo. Two part epoxy that spreads like bondo. You can actually see the catalyst fuming when you open the can. I got it at a boat shop. It's designed to be applied underwater to a boat with a hole - mix it, laddle it, go under, and slap it over the hole. It'll displace the water and chemically b ond to the fibreglass - kind of like emergency repair bondo. It is sandable and paintable. I used it to completely rebuild the windshield and rear window rails on a 70 Challenger. The rot went all the way through and almost all the way along. I had it sandblasted, then POR-15, got tacky, fibreglass cheesecloth, more POR-15, got hard, Marine Tex, got hard, trimmed the cheese cloth, and presto - new window channels. It's an amazing combination for channel repair work or covering a hole.

- S

 

[Hunter4x4]

Thanks guys - I'll post back later and let you know what I do and how it turns out - leaning towards the POR-15 route right now!!!



Mike

 

[JLEONARD]

Sam, I'm very familiar with Marine Tex since I'm a boater It is good stuff.

but I would think that an epoxy resin such as West Systems, would be as good or better and is also available in the larger quantities that we would need for these repairs.

Thoughts?

 

[wtrenholm]

I used FUSOR plastic repair on my kids Cavalier to stop the water leak around the windshield, not the right stuff but worked. The car was black and FUSOR is black so it looked acceptable. She only drove the car another year and it wasn't leaking when we got rid of it.



My '91 cab was getting so bad you could just about throw a cat through it, got real tired of the constantly wet floor. I'm in the process of a 3" chop, I have to go out back and cut one more roof off for another front corner. Will end up sectioning 4 roofs to get it all together. Still have to figure out how to deal with the wing windows, I don't want to eliminate them completely. The cab looks pretty neat so far. Hopefully it'll all work out and get finished before it's eligible for collector plates.



Wayne

 

["Mad Max"]

J -

Not sure about the West System - never used/heard of it, but I have no doubt it works . I guess that really any of these 'industrial' (read - expensive) catalyst epoxy's are worth the $.

To be totally honest, if the rust is that bad, replacing with a section of roof may be the best option. My 78 Ramcharger project going on now will have as little bondo as possible. It'll be all-steel underneath, all POR-15'd and epoxy primered and topcoated, and the only bondo on the rig will be where it needs to be 'straight'. But, I'm also doing the quarter panels - lots easier than a roof.

ALso, be sure to trace down where the water/rust originated from in the first place, and close that hole too . Coatings will work on the steel it touches, but the rust will still go to where the coatings stop...

- Max

 

[Don in Missouri]

POR 15 also makes a something called Por Patch that comes in a tube. That is what I used to repair my rusty rain gutter.



If anybody needs a roof section, I still have this club cab section to get rid of. There are photos posted at www.imageevent.com.shaggy/4sale

 

[91W350]

Not a solution for your problem, but a thanks for posting it. I checked mine and the sealer looks like chalk. I can rub it with my thumb and it falls apart. The only cancer on my truck is at the bottom of both doors, right in the seams. I suspect I will be searching for door skins, I am going to try bead blasting and Rhino coating them first. You probably saved me a future big headache by posting this thread. I plan to sand the bottom of the drip rails and to just have the whole roof Rhino coated down to the seam in the back of the cab. That should give it a little deadening and stop the water forever. I hope!

If your truck has surface rust only, I suggest blasting it to get it really clean, priming it with a qulaity primer, then applying a quality bed liner to it. You will be done with the problem and it will last longer than your truck. I am partial to Rhino just because I have been exposed to trying to remove the stuff, hours with an air chisel! Glen

 

[Scot]

What about using the panel adhesive/epoxy over POR15?

 

[JCrank]

Another good way to prevent rust even on an older rig is to spray boiled linseed oil on the under side of the vehicle, inside the doors, take the sun visors and dome light out to access and spray inside the cab roof, etc... . It is some pretty strong smelling stuff so use it during the summer when you can keep your windows down for a while to help with the odor. Quite a few of us use boiled linseed oil on our vehicles here on the OBX as a rust preventative. If it can't breathe, it can't rust ? If yopu spray the under side of your truck, make sure you keep the linseed oil off your driveshafts and brakes.

 

[Hunter4x4]

Update!

Well, it aint't perfect, but it didn't come out too bad! I can always go back later and clean it up with another pass of body filler!



I used the method suggested my Sam (Sam's Rams) - clean it up, coat of POR15, when it was tacky laid on the fiberglass screen, 'nother coat of POR15, and then Marinetex. Like I said, it really didn't turn out too bad! Because it's so high up on the roof, you don't even notice it unless it's pointed out.



The rust was pretty bad - but I had a lot of drip rail left to work with. The Marinetex filled it in real nice.



Next test will be next spring after I've gone through a Michigan winter!!



I have a spot right on the corner of the driver side that is going to need some work soon - but not right now!



Now I gotta get some clearance lights! (If for no other reasn to lay a bunch of POR15 inside the sheet metal up there!)

 

[DThibault]

my 91 is exhibiting the same symtoms, I have been looking around and found a few in junkyards. The guys there showed me two different fix jobs. They just take the whole roof section, cut the windshield posts, and go all the way down the back of the cab and cut at the factory seam at the rear of the door opening above the rocker panel. It came out real nice they say it is an easy job. I still have reservations but I think I may try it.