I think the rust starts due to condensation collecting inside the roof. There is zero insulation between the outer skin and the inner skin, but there is a fairly large area between the two. I think that condensation collects in this area, runs down to the windshield area and sits there causing rust. The other problem I have is that the cargo light is not sealed to the cab real well. I had a little water getting there. Luckily I caught that problem before others developed. Now I am trying to figure out if there is a way to get insulation in between that inner and outer skin. I was thinking of using that two part expanding foam...

 

1st gens. rock, they are greta work trucks, great freeway trucks, and could pull w/e you need, just have fun with it!

 

My '74 International has the same condensation problem. It's a tough repair because so many seams come together up there that you can't get to and you have to take the windshield out; a lot of risk to the windshield.

 

"... I was thinking of using that two part expanding foam..."

I used the expando foam on my crew cab, mostly to stablize the outer roof. When I got it, it looked like someone had been dancing on the roof and it took me a week to beat the crown back in. Old Dodge crews don't have ribs in the sheet metal, just a crown. I did not want it to flop in the wind.

Be careful with the foam however. I put mine in through an antenna hole in the center of the roof. I put a straw on the end of the hose to get all the way in and slowly withdrew the hose as I squirted. When I was all done and all puffed up with self pride , I came down off the ladder and looked inside only to see bulges in the steel ceiling (no headliner) So watch it. That foam has amazing psi.

 

trooper thorn i have the can in hand to do the same to my 78 crew cab gotta do something the noise from the outer layer of skin is terrible. i was going to bore several small holes for the straw on the inside because i am going to use a headliner of some sort. let me know when you start your work like to see maybe we can cross some of the hurdles together instead of alot of headscratching . (at least in my case) my wife just informed me about installing power windows and doorlocks i would be interested in what you used.

 

The hose on the straw worked great. I filled my entire roof from 1 hole. I just should have stopped squirting sooner. Don't feel like you need to use the whole can.

For the windows and door locks. I bought two doors off a '89 Ramcharger at a wrecking yard. I used everything but the sheet metal. The green glass relpaced my clear. The rubber parts were 15 years fresher. The inner panels had the switches, and they even had a perfect set of 1st gen. mirrors. I could not replace the doors outright because of the upper body line, but I took all the innards out to put in my old doors. The only mod was a approx. 2.5 in. hole where the window motor mounts and big holes for the wiring harness gromets. I used the Ramcharger door for measurements and used a holesaw or a jigsaw. I also got the wiring harness for the doors from the yard.
PM me if you have other questions. I am hoping to start the ctd conversion in June. It will take a while to get the truck right because after ten years I have to refix the rust at the top of my windshield. I might cut the whole thing out and replace it with the front of a newer standard cab I have.

 

cool. i just picked up two more doors today for the rear off of craigslist. can't hurt to have spares. my donor rig has electric windows and doorlocks hmmm . i take it you didn't upgrade the rear doors to electric right? this summer i will make several trips over to cental oregon to farm maybe i can make a stop to see how it coming and lend any help.

 

Correct. I have not figured out the rear doors yet. The kids have to crank.

 

i have a suburban body with four electric windows and doorlocks siting here to part out . have to take a gander look inside the doors.

 

This is one of those cases where I know just enough to sound dumb but be careful with the type of expanding foam you get.

There is a laytex type that doesn't have the expansion pressure of the other and tends to not deform what ever its injected into. Its for around door jambs and window frames.

But more importantly, pay attention to whether you are using open cell or closed cell. When I did my addition to the house I was told to only use closed cell in the catherdral type ceiling since there would be no air circulation like a regular attic. Same situation as your cab basically. An open cell foam would absorb moisture like a sponge while the closed cell will do the insulating w/o soaking up water.

I'm way out of my territory so somebody correct me if I'm wrong

 

krb thats the same info i was going by looking at house foam isulation and closed cell sounds like the way to go. the can of goo i bought says waterproof and is able to seal leaks. still wondering thought closed cell foam was all two part chem.

 

My thoughts too about the two part = closed cell. I also remember where I found on line where you can buy small do-it-yourself two part foam kits. Not sure of the square footage but the smallest cans are like a small propane tank. Would do way more that a cab but if you had a shop to insulate too or something else then it wouldn't be a waste.

 

i saw that hobby shop carry the closed cell foam for the hobby boats . only thing is it is two cans of liquid you dump together. i would like to inject from the headliner up and without rolling the whole rig onto the roof don't quite know what to do other than dualling syriges.

 

Dang! I guess living in New Mexico has it's good points, I haven't had any rust problems to speak of, just stress fractures in the bed and behind the wheel!

Back to the original question now that he is scared away, It's good to have a truck that has a cast iron drivetrain. The 1st gen trucks are the last of the true Power Wagons ("W" series) and I think are the end of a legacy of "form follows function (and ultimate comfort) Dodges that started in 1941.

 

Woops!

Thanks for getting us back on track