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Author Topic: '78 Econoline Fibreglass Roof Repair *HELP*  (Read 590 times)


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'78 Econoline Fibreglass Roof Repair *HELP*
« on: September 06, 2020, 01:09:38 PM »

I have a camper I've rebuilt the motor and now am moving onto interior build, however the roof is made of a fibreglass shell and is full of pinholes, causing water to leak in everywhere. I had to fully gut the original interior as a result of it being covered in green moss and mold.

I'm wondering does anyone have suggestions how I should patch this up?

I have access to a friends spray gun for gelcoat/topcoat but also am considering doing the matting / resin way and cutting the roof off flipping her upside down and refibreglassing the inside (there's some rotten wood boards attached to the roof fibreglass that needs to be taken out and replaced during same time). Im considering options, whether to do matting / resin inside, topcoat outside, or just spray a coat of gelcoat inside and toss rubber on the outside, or any other options anyone can suggest. I'm just a newb when it comes to fibreglass, and I dont know the best course of action to take in regard to this task. It seems a bit daunting and I could use any advice, feedback or suggestions! I appreciate it a lot!!



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Re: '78 Econoline Fibreglass Roof Repair *HELP*
« Reply #1 on: September 11, 2020, 07:11:23 AM »
Very interesting post to me anyway.  When I was a kid a had a few years of eXperience in the MFG process of Raw Fiberglass materials (Resin / Catylist / Roving /  Mat / Aerosil formed resin putties, molds etc).  Makes me itch just thinking about it.

Here is my $0.02.

I looked at the pics and there is many ways to skin this cat.  Yea you could do what you say and put rubber on it if you wanted to I guess.

To remove the roof with no reinforcement X Like Bracing that open lid of the van could come out of Square, whether it has been wrecked or not.  That is a huge surface area and that thing may have not fit like a glove to begin with even at the factory.  If it attaches at bolts like on the belt line where the Fiberglass Perimeter mates with the van roof and if you had it on blocks leveling the way it sits along with bracing something to keep the twist and torque from flexing when parted maybe, I might roll the dice and take it off.  Half the connections and screw points I am sure would have to been repaired and retapped.  I would have to really look at that, but a roof going back on as easy at it came off...LOL. Good luck.  I dabbled in Automotive Unitized collision repair too.  This I think is a frame not unitized body so maybe the twist would not be a factor? 

There is a very possible danger you now have a twist and the parts won't want to cooperate going back together.  I would probably avoid it. Labor hours would be more that it is worth to me.  if there is a structure rot you may be able to create a new brace with wood strips, screws and a glas patch. 

For Repair: If it was me I would get some mat cut 12" circles....Fray the edges so it dont have that pizza crust edge.  Cut and pull edges with dry clean hands and scissors/

Your going to have to lightly run a grinder over the entire inside fiberglass area  ....Tyvex suit, glasses, gloves, Respirator and you are still going to be wondering why you are itching later...Let her rip and give it a go.  Prepare to Embrace the Suck of working with Fiberglass because every time you scratch for the next week you are going to have Day-Mares.  Those are just as bad as those Scary Nightmares you can't get un-trapped from your mind. LOL  :-X

Get card board.....Slop some premixed Resin and Catylist...on the cardboard......throw one 12" frayed piece of mat....not roving on the cardboard....Slop Blot and infuse the resin to mat making it saturated by blotting.....now slap a big brush full on that interior headliner area peel the wet mat....and fling it up on the roof like a pizza crust maker........blot the air out with your resin infused paint brush.  Slop it around and be wet, but clean. Butcher paper areas you don't want to be sanding later!  You are going to do some type of headliner anyway. finally a thick coat of just painted resin coating your new masterpiece....This will probably add a total mat and resin coat 1/8" new skin to the inside.

Yep just like Johnny Cash...1 Piece at a time.

Prep on cardboard....slop roof wet....blot piece up there.... Repeat, Repeat

You get those pieces too big and gravity will work against you. 

At the factory the roof mold sits like a open bowl, usually on a rotisserie, Mold waxed, Gel Coated....Blocks added, Thick Roving Added and wetted.....the glass usually shot at factory is not mat but looks like a thing multi stranded shoe string.  The Boxes probably contain 5000 ft of stranded mat....the gun has razor blades on a roller so it is chopping and throwing fiber hairs and wetting them.........then then air is rolled out by had using a special small fiberglass roller.

I am guessing .....2 gal min maybe 3....resin.....Mat....Roof area +10% for good luck.  That mat will soak up alot of resin.  Mat has to be blot saturated or poured on resin and blot totally saturated/

Note: Don't mix your resin too hot and don't prep you wet mat in direct sunlight as the sun will accelerate the set of the resin to glass.

To paint the slick axx gel coat shell the chances of bonding would be slim and sanding the gelcoat from the roof that gel is only 1/16" think at MFG sprayed directed on the was mold so if you bear down to hard you will grind off the slick....finish and get back to the mat fibers.  After the interior side repair you can prep and paint the slick gel-coat for a better look. That Gel coat if you want it to look slick when painting it I would be 400 wet sanding not hitting with 80 grit and spraying.  That roof has so many oils and tree saps on it needs dawn dish soap scrub, 400 grit, prime and block and reprime and wet block, wax and grease remover then mask and paint. 

As with any material prep is key. 

« Last Edit: September 11, 2020, 07:46:10 AM by X-Roughneck »


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Re: '78 Econoline Fibreglass Roof Repair *HELP*
« Reply #2 on: September 11, 2020, 07:42:10 AM »
Edit Deleted post: X Roughmeck said it better  8)

For others: the links don't follow great maybe because of the parentheses, but it is a Class B with extended fiberglass top.

Maybe try these links

« Last Edit: September 11, 2020, 07:48:30 AM by SpencerPJ »
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Re: '78 Econoline Fibreglass Roof Repair *HELP*
« Reply #3 on: September 11, 2020, 08:02:40 AM »
Spencer to fix that old "Mature" Van going about it from the top side is not the way about it.  The build has to be from the underside.

This probably resulted from 20 years of Weather, plus probably a guy who sprayed gel coat too thin, shot rows of mat uneven during MGF.  Shoot wet glass is just as artful as shooting paint...Well maybe not that technical but there is a way to do it Really good.  Also who knows what type of structure was added to the inside of the mold? 

They make some hightech stuff like sheets of small blocks that will soak resin and add structure to the thickness.  THis is Old school stuff on his RV?

This stuff on this roof looks like, well..... Thin wood that they added to the mold to give it the rigidity?

The roof edges look like there is some meat there.  Roof failure is low and I bet a 300 LB man could walk on it and not sink down below his knee worst case scenario. ;D 

« Last Edit: September 11, 2020, 09:20:14 AM by X-Roughneck »

Gary RV_Wizard

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Re: '78 Econoline Fibreglass Roof Repair *HELP*
« Reply #4 on: September 11, 2020, 08:37:06 AM »
I'm having some difficulty imagining pinholes in fiberglass. Deterioration of the fiberglass itself? Or some sort of external damage, maybe acid rain?  I would worry whether the roof remains structural sound if numerous holes have been eaten through it.

If the roof is still sound and leakage is the only problem, I'd suggest just coating it on the topside with an elastomeric (aka  rubber) roof coat product, which ought to seal up the pinholes nicely and last another 10-20 years.  But if not sound, you need to repair the roof with layers of new fiberglass.  Gel coat is mostly for looks - strength comes from resin and roving (mat).   X-Roughneck has explained how to do a quality job of that.   I'm not sure the project would be worth that level of effort & expense, though.
Gary Brinck
Summers: Black Mountain, NC
Home: Ocala National Forest, FL


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Re: '78 Econoline Fibreglass Roof Repair *HELP*
« Reply #5 on: September 11, 2020, 09:19:32 AM »
Yes Mixing up some texturing thing and applying from Top side is the lesser of all evils.

Pinhole thru the entire structure does make one go, really? Gary brought up a great point to ponder?

There maybe a torrid chapter in this book of "Old Van" we don't know about?

Was this damaged before? We do not really see the problem area. 

The gaps on the doors look semi straight as the upper right door is low and the snow on the bumper is only a optical illusion as it does look pretty square, non wrecked or good repair from low angle viewing.

As seems very strange as to why pinholes thru what should be approx 1/2" min of gel, block, roving, mat and gel combo.

Is that a DIY sunroof..LOL?

Lots O Labor on that bottom side repair, fumes all kinds of _____ just to ruin you day fully. 

Please Fill in your own blank.

Unless your trying to win a beauty contest go the easy route.  ;D

« Last Edit: September 11, 2020, 10:17:07 AM by X-Roughneck »


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Re: '78 Econoline Fibreglass Roof Repair *HELP*
« Reply #6 on: September 12, 2020, 12:49:41 PM »

Thanks everyone for replying back with all the detailed comments. I have taken some better photos for you here:

*edit (Links)*

The circled parts in the pics are where the pin hole examples are, although they are scattered everywhere if you look hard enough! This is why I'm thinking a full re-coat would be better than individual patches (to not miss any!). Basically anywhere sunlight is getting through the roof, is also allowing water to seep through drop by drop. I had to gut the original build because it was covered in fuzzy green patches lol.

Also I took a pic of a rotted wood board that is attached to the fiberglass, i plan to replace this one, i think this may be apart of the fiberglass roof for structural support, or for the cabinets to screw into? I'm not quite sure its purpose. Either way its rotting and should be replaced, but I worry about the fiberglass breaking around it when I go to remove. I will have to carefully grind off, or?

The roof is attached with screws all around, i provided a photo from the inside and outside of these screws where it attaches the two pieces together. Also provided is a pic of the top of the roof

Would it be enough, long term, to just add new matting & resin on the inside? Or should I also coat something over the outside? I'm thinking coating inside for additional structural support (because i dont know the integrity of this one), and outside coat just to assist with preventing water sitting in the holes. That's my thought, at least. This elastomeric product intrigues me, certainly something to further research into. Thanks for the suggestion!

My girlfriend and I have been on the roof at the same time on a few occasions and it felt pretty solid. I think fixing the roof up would be much less of a hassle than selling her (at a loss) and buying another van to start over. I fixed all the mechanical up and she drives solid now. The van has been sitting in a farmers field for 15+ years, the previous owner used it to drive his wife up a hill in the winter times. It is definitely weather worn from sitting rarely used.

Roof is an original vanguard shell, as is the entire camper.
« Last Edit: September 12, 2020, 12:54:14 PM by vanlife204 »


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Re: '78 Econoline Fibreglass Roof Repair *HELP*
« Reply #7 on: September 12, 2020, 01:03:20 PM »
Also a special thank you to X-Roughneck for the detailed instructions. I definitely feel more confident going about this as a DIY job. All the tips and suggestions are appreciated.


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Re: '78 Econoline Fibreglass Roof Repair *HELP*
« Reply #8 on: September 12, 2020, 06:38:39 PM »

She is a Dog for sure. Not here to crush any dreams though.  :-X
You have a serious cancer growing there, and more so on the metal side than probably your crown fiber glas side. 

To correctly repair it, a professional would need to be sectioning it out and replacing the rot if they were worth their salt.

You could poor boy a repair yes.  Would you be a menace to society driving it down the road?  That could be a subjective call, depending on the person making it.

Would it be a long term patch.  No, You got Rot that needs addressing.

As far as the "Seaworthiness" of your Titanic II anything is doable, but the skill set here to do it right you need carpentry and auto body Repair skills. 

I bet your leaks /seeps will be massive along that belt line where the sections meet trying to attempt a poor boy repair.

** I am looking at that pic where you have the 4 screws circled.  Is that Rust the top of the van edge where the crown mates up? if so , definitely not good, just shows the level of rot in the metal.

What do the floor pans of the van look like, Rusted too?  Hope not.

In tact exterior Paint remaining is probably your biggest supporter of holding back water from seeping in at this point.

You are going to have twist and some flex traveling and banging down the road. Flex, Twist along with Rot is not a good combo.

Without real repair Skills you should not dig in deep and remove that crown. You will be regretting that as you are hauling Old 78 Betsy off to the Junk Yard. 

Patching is your only real hope and that is equivalent to buying a pill on TV that says you can lose 30 pounds in 30 days. Yea…It is possible I guess with amputation.

For most of us, this type of repair, it would be in the “Kids, Don’t try this at home" category type. 

Being a realist, anything other than cutting away the rot is just polishing the turd and you are faking a repair. 

I am not here to knock your vision.  Anything is possible if you throw some cash at it, or have the DIY skill set to pull it off.
I just don’t want to be legally liable where I can be quoted on the forum telling you there is no worries either of your crown flying off killing the motorcyclist behind you. 

Naaw Just joking… 

That Fiber Glass wont break off.  The Metal on the van, well not so sure….? 

Just don’t drive over 70 MPH.

Realistically, the metal on the van where the crown mates to what was original Roof, Belt line, that is the weak link not the fiberglas, although the Glas does needs touched up a bit?

As for bonding new glas. 

First of all the surfaces should be ground, cleaned, or sandblasted or wire wheel on a rotary tool, air blown clean before any bonding should be attempted.

Usually when you are bonding glas you want the pieces to lay flat, not have a crinkled edge and your rotten portion is just that Crinkled.

The section of glas you lay, your goal is to roll or press out the air out of the mat fibers with the resin tight like applying a band aid to your skin. 

You can see much of that fiber roof shows its long term durability just by looking at it. 

This  severely rotten section you can't bond new glass to brittle destroyed section of rusty Van, clean or grinded sand blasted metal yes. Rusty metal no.  If you took a grinder after that metal it would dissapear as dust.

If somebody told me John, your going to war with this old dog and I had to fix it and go camping, I would attempt to fish plate it. Meaning the Horizontal line where the crown meets original van roof, bond  to a good structure on both the metal and glas sides, which will be nearly impossible.

No matter what you do, your going have this problem if you slam gunk in that gap of rot and create a blob of a gooey repair, by fish plating and patching by putting a huge band aind around the inside belly…

You go out the drive way and you hit a bump and you get flex, crack and there is your new leak, or pocket that retains water furthering the rot.


« Last Edit: September 12, 2020, 07:08:44 PM by X-Roughneck »

Gary RV_Wizard

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Re: '78 Econoline Fibreglass Roof Repair *HELP*
« Reply #9 on: September 13, 2020, 12:33:11 PM »
I didn't realize it was an old Vanguard shell when I first responded - should have looked at the photos then. Man, that thing is rough!

I'm torn between the "poor boy" approach and going whole hog. Maybe depends on the budget and planned use when complete. Since both top and sides need help, my inclination is to remove the entire shell and give it the works, replace wood as needed, resin and roving on the inside, and an elastomeric roof coat on the outside top for good measure. Obviously need a covered place to work, though even a tent would probably do.

If that is too much work or expense, I'd go to the other extreme and just put an elastomeric coat on top and fix up the sides seams and rotted wood by whatever expedient means is possible.  There seems little point in doing a halfway good job - either "poor boy" all the way or do it right.
« Last Edit: September 13, 2020, 12:36:43 PM by Gary RV_Wizard »
Gary Brinck
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Home: Ocala National Forest, FL


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Re: '78 Econoline Fibreglass Roof Repair *HELP*
« Reply #10 on: September 13, 2020, 01:25:25 PM »
I certainly don't want to discourage you in any way but my daughter and SIL bought a late 70's camper van a few years ago. It had sat in the PO yard for years. Everything was in great shape except the front floorboards and rear deck were rusted out from the grass growing up under it for years. The shag carpet was hiding all the damage until they went to replace it. On further inspection all the mounts from the body to frame were toast also. They were afraid they'd end up with a low rider after hitting a pot hole;) You've also had a leak from above so I hope you've checked out the bottom of your van.
Retired computer automation programmer
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