Fiberglass questions

The screws basically are on the horizontal plane, a little downward.

Since original screwholes in steel were rusted out, and I did not want to drill all new holes every 4 inches in fiberglass, lifting it and moving it backwards a bit were my solution.

I lifted it from the inside with a hydraulic jack.

I also removed some fiberglass from the bottom lip and on the leading edge to get it to fit tighter up there with less sealant required.

the screws in front are trying to penetrate steel at a ridiculous angle. pretty ineffective.

I now have threaded brass inserts submerged into homemade fiberglass rope ~ 3/4 inch diameter dry, saturated with epoxy along leading edge, and stainless pan head bolts pulling roof down tightly over windshield.

Ridiculously strong

landyacht318 wrote:
Fiberglass is pretty flexible.

I lifted mine in the back about 7/16 inch over what the conversion company did, which was to allow it to rest in the gutters so that one had to clean leaves and detritus out with a specially designed tool with a Z type shape.

I'd say it was Designed to fail, but that would imply they thought at all.

Ah, lifting it! I thought you were talking about flexing it inward, which would obviously work in small patches but not all around unless it was made small ;).

Did you lift with washers under the screws, or???

Fiberglass is pretty flexible.

I lifted mine in the back about 7/16 inch over what the conversion company did, which was to allow it to rest in the gutters so that one had to clean leaves and detritus out with a specially designed tool with a Z type shape.

I'd say it was Designed to fail, but that would imply they thought at all.

Great advice and cross section! Thanks!

I am not sure how I would have much choice on where the roof sits?

Yes, mine is a dodge, but I believe if you see roof gutter rust mostly on them, it is because there is more of them floating around.

Here is the convoluted upper rail and gutter cross section of a Dodge.



I imagine the fiberglass roof is made one piece in a mold, I am not envisioning any benefit of having 2 pieces and making a seam, not in something the size of a van roof.

If you buy a van and cut the roof off, I'd recommend treating any rust and repainting it. When cutting out the steel, I'd recommend painting the edges of the bare steel. Use stainless steel fasteners, but predrill the holes vacuum out the shavings run the screws through the steel to cut the threads, back them out and paint the holes.

Leave enough room so that the fiberglass roof is not resting on the roof gutter bottom, partially blocking some of its width.

My roof, with nothing attached to it weighs about 220Lbs.

If cutting the steel roof with a cut off wheel, protect any of the vans paint from sparks which will sear into the paint and cause little rust boreholes in the paint.

Ah, thank you very much, landyacht, for the gutter rust education.

What brand is your van? I've noticed that Dodge vans all seem to have a lot of gutter rust even without a fiber top. There seems to be some sort of design flaw there.

One thing that goes through my mind when van shopping is: Is it wasteful to cut up a perfectly nice van; should I get a less perfect one because I am shortening its life? I guess my ideal van if doing a transplant would have a big hole in the roof but be otherwise perfect ;).

Can you, any of you, tell from the pics whether the top has seams? The seller, the friend I took with me, and I were all a bit stumped. It has those LINES but we were not sure if they were just decorative.

Naio wrote:
Interesting, landyacht! Does that mean that if I got a single-layer roof I could have fiberglass glass in some wood to screw cabinets to, and to support solar? That might he nice.

What is with the gutter rust? I see a lot of that. Is it due to the screw/bolt holes? And/or the lack of air circulation where too nany surfaces come together? (=Is the rusty worse under the top where it is hidden?)

I really do not have experience with other fiberglass roofs to know how they are constructed. I have many rope cleats into the wood runners, but also have some White oak strips holding up some white panelling to also firm up the roof.

Cabinets, suspended? I think not. I only feet safe using 3/4 inch #10 coarse thread wood screws into the wood .

My framed solar panel's corner feet/supports, I fiberglassed to the roof after sanding through gel coat. The other solar panel is a stick on unisolar pvl-68.

I worked in a boat yard for a few months, fiberglassing molds and such. There is lots of room for imperfection in the process, and the workers sniff too much fumes. There could be much variation in where they place the wood from roof to roof.

One can't really see how it is constructed until one removes all the interior from it, and even then some of the wood and foam came as a surprise to me.

The roof gutter rust is the Van killer. When they attach the roof sheetmetal to the walls there is a whole bunch of folding and body filler and spot welding going on. Once moisture gets inside, inbetween these layers, the rot begins and festers, and one can only hope to slow it down. When the conversion company used drywall screws, well drywall screws will rust before your eyes if you breathe on them. So mine had the double cause eating upwards from the water trapping gutters, and downwards from the born to rust screws they decided upon using to hold the roof to the steel.

Condensation from living inside is also an accellerant of the rust.

Th gutters trap dirt and contaminants which eat the paint. Keeping them clean, parking so that overnight condensation can drain rather than pond, and waxing the gutters can really slow down the rust. BUT, many fiberglass roofs have a band making it extremely difficult to actually access the gutters to clean and wax them. Basically they were not built with longevity in mind.

I had my fiberglass roof removed completely twice to repair rust and repaint. other times I just lifted it enough to access the rust and treat it. That option is pretty much closed now. My rust battles are being fought in full retreat.

Naio wrote:
Hello everyone!

In my search for a new van, I am thinking of getting one with a high fiberglass top. Or having a top (used or new) put onto a van.

I'm reading up on restoring fiberglass and have a few questions.

- Is washing off the oxidation of, say, a 35 year old unmaintained top an itchy process? It seems like it would be! But I see no mention of that. I'd like to know before I start.

- Someone on another forum said that once the original gelcoat breaks down, fiberglass becomes porous and leaky. Is this true? Sounds like a disaster. What do I do about it?

Thanks for helping me scope out my options, :)

-

Answer 1: Not that I ever noticed,, But the gel coat and paint do tend to "Bind" the fibers.

Answer 2: Very likely it will become porus, but re-painting fixes that, so does a good coat of wax.... But only for a short time. (in the case of wax)

Interesting, landyacht! Does that mean that if I got a single-layer roof I could have fiberglass glass in some wood to screw cabinets to, and to support solar? That might he nice.

What is with the gutter rust? I see a lot of that. Is it due to the screw/bolt holes? And/or the lack of air circulation where too nany surfaces come together? (=Is the rusty worse under the top where it is hidden?)

My fiberglass roof is a 'tv' top conversion van roof. In the back 2/3, it has ~ 3/32" of fiberglass on the top surface, then ~ 3/8" of foam, then another 3/32" of fiberglass..

Below this they used 4 inch wide strips, 5 of them, about 9 inches apart of OSB particle board and glassed than in with 3/32 more fiberglass.

These OSB strips hold a screw from underneath nicely. I've reinforced the underside/ ceiling with Oak and insulated it with 1/2 inch isocynate foamboard insulation.

The front 1/3 is just 1/4 inch of fiberglass, fiberglass matt, or perhaps just fiberglass sprayed into the mold with a chop gun. No foam, no OSB wood, just the convoulted structure and 1/4 inch of fiberglass to give it some rigidity.


Exactly how these roofs are constructed will vary.

I would NOT walk on ine without plywood up there to spread the load.

The original conversion van maker decided that coarse thread 3/4 inch drywall screws into the sheet metal roof was 'JUST FiNE'

Effing b.stards.

My battle with roof gutter rust is a battle I am destined to lose, but it is a battle i still fight.
Thankfully I can get epoxy to bond to properly prepped steel and aluminum, and have rebuilt parts of the roof gutter.

But this effort is also futile, in the long run.

Those pics look more like dirt rather than massive gel coat cracks. get a ladder and some spray cleaner and have a better look. try and feel for soft spots.

Fiberglass is good stuff, Better than steel for long term durability.

Especially when they use freaking drywall screws and whisper the 'just fine' mantra which apparently soothes the human soul.