Hey I finally got my 92 w250 back from PA and its got some rust on it. Most of it I wont have any problems fixing myself but I was wondering if anybody had any ideas on This rust here on the roof, its leaking water in and I was thinking about cutting out the rust and patching it and fiberglassing it but wanted some opinions on it. Thanks

 

Your best bet is to find a decent cab and just swap it out. You won't know how far the rust invaded until you cut it all apart.

 

im thinking about doing this to my roof.....

http://1stgen.org/viewtopic.php?t=42...asc&highlight=

 

Hey amc3604me

My buddy had rust just like yours so does mine i havent fixed mine yet but he just cut it like oilcan64 and got another good front piece from the junkyard and welded it right up no leaks at all.


His second layer was not rusted all the way through so he just put that por4 stuff i think its called on it and it works and looks great.

Hope that helps.

 

Wow thanks for that extensive link, that was very helpful. Has anybody thought about using fiberglass resin and bondo after they cut out the rust cause Im tryin to go for the easiest solution. Especially with the weather, Im a driveway mechanic and an extensive body shop job doesnt sound to good with the temp being 15 degrees ha. I will probably end up doing that if its neccesary or in time when i have a nice place to work on it, but im just wondering if I could succesfully patch it myself.

 

12+ years ago, I cut out all the swiss cheese and treated with rust mort the metal that was still solid. These days I would paint the pitted metal with por-15. After it was all cleaned-up, I slid new steel up under the roof and tack welded it all up. I then used "Kitty-Hair" (fiberglass) to smoothe out the roof. If I were to do it again, I would use "All-metal" (aluminum fiber in some kind of resin. This truck has sat out in the Oregon weather ever since. It still looks pretty good.

 

The roof rusts from the inside outward so the rust you see is actually just what is breaking through. If the stupid tight wad Chrysler engineers would have been generous enough to have just specified the inner roof surface to be painted before assembly we then would not have this issue today. Planned obsolesce at its best now rearing its ugly head...The only semi-permanent way to fix this is remove the inner roof panel and then remove the rust, treat the inner roof panels, and reassemble. But Chrysler engineering was wise enough to pinch weld the inner roof panel to the inner rear cab panel making this type of repair almost impossible. So the only real fix is finding a good replacement roof, rust treating it the best you can, and installing it by cutting it at the A pillar and in the rear window area.

 

Yea, I'm in the same exact boat and looking into getting a local body shop to do my roof rust and at the same time repaint the truck (or in my case the cab). I'm going to be taking my rusted Knapheide flatbed off prior to delivering the truck to them and looking to make it like a new looking truck again. I mean past the stupid design on the cab itself, they don't build trucks like this anymore hence my reason doing the work to make it as close to nice and new again.

 

Every year I take in the interior trim screws out and blast WD40 into every hole I can find. I can only assume this helps keep moisture out.

 

My '80 crew project has some rust above the windshield, right below the drip rail. Where there is pitting it's from the outside going in, not coming from the inside. Looks like the seam sealer shrinks and dries out allowing water to get behind it and do it's thing with unprotected metal. Also, the clearance between to drip rail (gutter?) and windshield gasket is so tight it doesn't ever get cleaned out. How about eliminating the "gutter" completely above the windshield? I'd really like to see a cross-section to see how it's put together - do you think they would mind at pick-n-pull if I cut a section out with my cordless sawsall?!! Any pictures I've seen aren't clear enough or the metal is too far gone to figure it out.

With rust that bad I'd consider replacing the whole roof or cab, but then others have had success patching.

If you have a headliner why not drill some 1" holes to get some access to spray rust converter/sealer in the roof and then cap the holes with plastic body plugs? I need to figure out where those holes would provide the best/ needed access.

Just some thoughts I had.

 

The part of the gutter that protrudes out and forms the bottom of the gutter accross the front of the windshield is a sandwich of three layers The top is the roof, the bottom is the part hat comes up from flange inside the winshield rubber, and the center is a piece if sheet metal that runs the width of the roof about six inches wide.

In this pic I am trimming the metal flush with the bottom of the gutter. Over by the pillars, you can sortta see the construction. The slightly rusty bare metal you see where the ceiling is cut away is the six inch strip of metal I was talking about. If you cut holes here, you will find the strip and not the roof.



Another pic



Now this green roof is a ramcharger roof from a pop top, so there is no windshield flange. Here, I am cutting off the roof gutter. In doing so, I am separating the ceiling from the roof. This happens because the sandwich I mentioned earlier is where the two ar welded together. If you remove the rain gutter on the front of a cab you are going to continue to use, you will need to weld the roof back down. This is what I did on the patch I mentioned in an earlier post on this thread. In the 10 years I drove that cc around, nobody ever noticed the missing rain gutter. I just turned the gutter back in to the cab at the corners by the edges of the windshield. It not only looked good, it probably got rid of a wind whistle and gained me .02% on fuel mileage.



After the gutter was removed, the top and bottom were two pieces.

 

Thanks Trooperthorn that helps. So when I stick my finger in the visor hole I'm touching that 6" piece, where they sprayed a dollop of asphalt crap to prevent rust! Sounds like drilling holes 7"+ back would help to spray some stuff on top of the 6" piece and closer to get under it.

 

Im pretty sure you can access the back from the visor holes.just get creative with the lps marine preservative.