I have a 1987 W100 that has some rust through on the leading (front) edge of the roof, and I was wondering how I could go about fixing it. I just dont know where to start on fixing the rust.

I do not have access to a welder, but my father knows how to work with fiberglass (he used to construct and repair fiberglass boats, and has used it to fix his old camaro)

 

If the rust is all the way threw than putting fiberglass on only one side of the metal is only going to be a bandade.The only way to repair rust is to get rid of it totally or to seal off oxygen from it, that means you will have to seal it from both sides of whatever is rusted through. If you can get to the inside of the panel than I would suggest a product called fiber tech it is a resin based with a kevlar and fiber filler it is a product that has work for me. I have also worked in a fiberglass "factory" we built accsesories for house boats (slides,fly bridges) I now do body work and I tell people who ask will fiberglass work to fix rusted metal I will tell them as I told you, I don't reccomend it but if you do it right it will hold up just not as long as metal replacement.

 

depends on how deep rust is. grind and bondo is possible.

 

It depends on how much you like the truck. If it doesnt matter, fill it with silicone or body filler. If you like the truck you will have to get the infected area removed. I got a quote for mine and it was around 1200 bucks.

 

If you really like the truck, and if it's as bad as my roof is, then it's going to be a jobe where you remove the windshield, cut out the affected area, using it as a template to make a new piece, and get access to a welder to put it in. Fiberglass isn't a great solution, and it takes a real pro for it not to look like **** or crack off.

 

im with Rampant - depends on how much you like the truck, as well as how deep the rustis. How close is it to the windshield? I wouldnt wanna mess around in that area. if it isnt too close to the windshield just grind the rust out, fiberglass and bondo. you cant see the roof unless you're six five anyhow, and there isnt much stress on it. id say that after the end of the second year that repair will begin to show blisters and so on.
since the rust is right through its aspecial can of worms. but how big is the crack/hole? ifsmall i wouldnt worry just make sure you get the rust off.big andyour best off to weldin some new stuff in- which really isnt that a hard if you dont care to get it perfect. you could grind theroof down about 2 inches from the hole all around it. Then cut some 22-guage and rivet too the shallow 2-inch lip you made. Better still put the new plate on the inside, or even both sides, then glass over that. Id glass the inside seam too. this will not last forever, but really only the very best repairs do.

my experience with body repair is that it is very unforgiving work. you could spend forever on that and itll come thru unless youve got that nack. plus if you dont put the best quality paint more problems are bound to come. So it boils down to cost. You can do what ive suggested for $50-100 plus a can or two of near match. Getting the repair done properly plus paint id say 2 grand.

like i say, depends on how much you care. cut the damned thing right open and have a sunroof i think