repair vs. replace fiberglass roof?

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Lorelei072

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Hello, all. It's me again.

What are your thoughts on repairing vs. replacing fiberglass van roofs? My rig is a '92 GMC/Explorer conversion in decent shape but there are issues of course with a 30-y.o. vehicle exposed to the hot southern sun. 

I previously posted an inquiry as to how to reseal my leaking skylights. I could not figure out how to remove them for maintenance without destroying the significantly deteriorated gasket material. I still haven't been able to find replacement gaskets after contacting Explorer, Safelite, and internet searches. It's unclear to me how to chose the correct gaskets without likely destroying the ones holding the skylights.

I found a marine fiberglass shop that's willing to work with me, but all he did for the skylights was goop some silicone to the outside. The leak was definitely coming from the skylight on the driver's side, but now heavy rains are coming through on the passenger side  :exclamation:  There is also some leaking in heavy rain over the couch that I sleep on. After checking the roof exterior, I'm 80% sure the water could be traveling down the length from the remaining skylight leak, collecting on a roof contour, and dripping off at that point. But there's a chance that water could be seeping through tiny cracks at that roof contour.

The marine fiberglass shop provided a couple of rather high quotes to restore the faded paint on the roof ($8k-$9k to grind off the old, cracked gelcoat, re-gelcoat and paint or $1200 to just paint it).

If I do the work myself, I'd have to buy the tools and materials. I'm not sure what that would come to, but it would cost way less than $9k. I think the whole project would cost me <$1k.

I foresee 2 problems if I redo the roof myself. I work full time so it would take quite some time for me to complete all the grinding. It rains quite a bit here. If it takes me 2 months to complete the project, how much water damage would I be exposing the foundation of the fiberglass and the inside of my van? I'm also concerned about new gelcoat and paint having time to cure without rain threatening it.

Secondly, I don't know if the roof will support my weight. [font=Tahoma, Verdana, Arial, sans-serif]I cannot find a 10' scaffold that I could drive the van through and position myself over the middle to work on every part of the roof. [/font]I spent some time searching, but I can't say my search was exhaustive.

A new roof would be about $3000 from Fiberine in California. It would be in better condition, painted, weatherproofed, and hopefully with additional height and wood reinforcement.

My original van build plans included wood-reinforcement of the fiberglass roof to attach cabinetry and even suspend a papasan or moonchair loveseat for an elevator-style bed. It was also important to me to be able to stand upright, but the roof I have now isn't high enough. I have to keep my head ducked about 2".
 

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I can;t tell you what condition your roof is in without seeing more pictures at the very least. If that is a picture of your skylight, that gasket is readily available at most glass shops, they sell it by the foot. you can get it from the CRLawrence catalogue, the chrome part lifts out the glass is pushed out then the rubber gasket can be easily removed, a pretty easy fix for any auto Glazier. All up with a reaseal shouldn’t be more then a couple hundred dollars, if that, they can do it in an hour. If you have never worked with fibreglass I wouldn t start trying to fix gel coat without being in a controlled environment. I am not sure it is worth it on that old of a vehicle. I would wash it thouroughly, sand it down, not grind it, wash it again and repaint it with a roller or a brush. Buy some very good paint something, that sticks to Fiberglass you may have to buy a primer as well. Go to a store that only sells paint and ask for some advise they will be able to help. Good luck. I doubt you need a new roof, and I wouldn t sink 9 grand in it.
 
What he said^^^ but the old gasket material is probably hard and most likely need to be cut to remove the glass without breaking it. The last thing you should use and then only in an emergency is silicone for a temporary fix as it is difficult to remove and must be completely removed as nothing will seal to it. It would have to be a much newer vehicle for me to consider putting on a high top unless I could do my own labor and find a junkyard high top to keep costs down.
 
flying kurbmaster said:
I can;t tell you what condition your roof is in without seeing more pictures at the very least.
Hope this helps
 

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Paint it, if you are not going to replace the rubber gasket I wouldn t use silicone as that will not adhere very well to the rubber you need to use a more liquid form of butyl ish sealant, most autoglass shops have a little pump can with a narrow tip that fits behind between the rubber and the fiberglass as well as between the rubber and the glass pay them to do it. It won t cost that much and think of how much you just save by not having someone regel your roof or replace it.
 
Way too much trouble and expense to try to repair the gel coat and it is not required that you do so.

You can clean the roof give it a light sanding, fill any voids and then paint it with Rustoleum paints using a small foam roller and brushes. The Rustoleum will stick just fine to the cleaned and prepped fiberglass surface. Plan on doing two coats.

Go to this fiberglass RV forum to learn now to clean, prep and paint fiberglass. You can also learn how to repair cracks of hole, how to remove and reseal the roof vent etc. It does not matter that you don't have a molded trailer, just go there to read the pre-existing articles about painting and putting in window gaskets and making fiberglass repairs. You don't need to get into the specifics of your hightop van to learn how to do those things. https://www.fiberglassrv.com/forums/

As to all those skylight windows, yes you should remove then and put them in with new gaskets. Instead of buying new ones if the old ones are too damaged you can have polycarbonate cut to fit into the opening and those panes will be installed with a standard type of window gasket. Any glass company can do that work if you are not a DIY person. But it is not an impossible DIY task if you have the small hand tool that makes it easy to put the gasket in. Also If you have a jig saw with the right blade for cutting the polycarbonate to the proper shape and dimension.

You could fill in those old skylight holes with fiberglass cloth and resin and again it is a DIY job but it will involve using a backerplate coated with a release agent, of course a flat surface to build up a stack of resin and cloth that you then transfer over to the RV to put in place against the backer plate. It is a bit involved, it takes some patience, best done with a partner for larger sized openings to carry the stack of materials from the table over to the RV and then secure it in place. You do have to learn the steps. I myself filled in several large openings on my former fiberglass motorhome but I did it using epoxy resin as I wanted to have a longer working time versus using polyester resin. However epoxy resin cost considerably more than polyester resins. I had no real clue how to do that kind of repair but I was willing to learn and I am used to doing various kinds of projects. My first step was to talk to a man who did fiberglass repairs on boats and he told me about using the stacks of cloth laid on a table covered with "peel ply". Peel ply is an interesting material, it is silk like, non stick, it allows you to easily transfer the stack over to the vehicle and it provide an easy to glide over surface for smoothing the stack of material and resin nice and flat. After the resin cures it peel right off and you a left with a nice smooth patch that needs minimal sanding. The opposite side is also fairly smooth as it has been pressed against that release agent coated backer board. There should be some useful youtube videos you can watch if you want to take that approach and not have skylight windows anymore. You need to paint the roof anyway so you put the filler patches in before you do the paint job. Good prep and finish work and no one will ever know that there used to be skylights in the high top.
 
maki2 said:
Way too much trouble and expense to try to repair the gel coat and it is not required that you do so.

You can clean the roof give it a light sanding, fill any voids and then paint it with Rustoleum paints using a small foam roller and brushes.  The Rustoleum will stick just fine to the cleaned and prepped fiberglass surface. Plan on doing two coats.
I'm just curious why use Rustoleum on fiberglass?
 
Lorelei072 said:
I'm just curious why use Rustoleum on fiberglass?
Because it has become time tested for staying stuck on fiberglass without peeling. Of course the surface must be clean, dry and free of wax or oil as well as loose oxidation powder to make sure there is good adhesion for any type of coating you put onto old fiberglass.

You can buy Rustoleum in thousands of locations so no hunting it down or needing to pay for expensive shipping. It is easy to apply and rolls out for a decent looking DIY finish on fiberglass RVs. What is not to like about all of that? :)

I used a marine paint on my fiberglass trailer but it takes two people to get it to work right and is fussy for temperature, too hot and it kicks off before you can get rolled on and tipped off, too cold and it sets up too slowly and is vulnerable to not being dry before the dew point arrives. If I need to touch a scratch or spot I can't just go to a local hardware or Home Depot and buy a small can of it. It also needs a special thinner.

So you might as well go with Rustoleum on a vintage fiberglass high top. Some people even paint the whole van with it.

Do learn the steps for a "roll and tip" finish.
 
I used to hang out with a couple of guys who worked on boats for living.
When I had my 77 Ford van it had a kind of rusty roof in the back. And I lived near the water so it only got worse.
On the advice of my boatwright friends I used some product which was kind of like house paint, kind of like fiberglass epoxy.
I can't recall the name of the type of product, but apparently it's used by boat owners for minor repairs of fiberglass. Since modern boats are 100% fiberglass there has to be a product like this, they can't be coming in to a repair shop for every little dent, scuff and ding.
They told me there is no reason it can't be used on an entire metal roof. It's tough stuff.
I sanded the daylights out of it with a buffer disc on a drill. Then painted it with a roller.
Looked less than perfect, but stopped the rust creep. Then I could focus on the ever leaking rear vent.
It was about $45 a gallon back in the late 90's. So probably twice that by now.
 
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