How to avoid forming holes in van high-top?

[debit.servus]

I am sure some people would just say go for it. Worst case scenario, your screws are too long and will for a hole from inside to outside. This tiny hole can be sealed with some kind of product.

This is what I am trying to avoid however. How can I figure out how thick the van's fiberglass high-top is so I can use an appropriate self-tapping screw? Aka, how to avoid forming a hole in the high-top?

I am planning to install divider curtains between the van's rear bed and living space.

Anybody have some ideas, tips, suggestions?

 

[MikeRuth]

Other folks with Fiberglass tops I'm sure will chime in, but I'd do it on the safe side and glue in mounting blocks first if I had any doubt as to weather a screw would go through. I wouldn't want one hole like that, cracks can and most likely will develop.

 

[Optimistic Paranoid]

How heavy are the curtains?

I believe I would try attaching a couple of blocks of wood - say 4" x 4" and an inch to an inch and a half thick - to the INSIDE of the fiberglass roof with that high strength VHB tape and attach the curtain rod to those blocks.

Regards
John

 

[66788]

Other folks with Fiberglass tops I'm sure will chime in, but I'd do it on the safe side and glue in mounting blocks first if I had any doubt as to weather a screw would go through. I wouldn't want one hole like that, cracks can and most likely will develop.

I just drilled about 30 holes into the high top of mine. Mounted solar panels, roof vent, and lighting. I was a bit apprehensive at first, but I can't see how this can be avoided to achieve a clean install of the necessary equipment that we all need.

If done properly and sealed properly, there should be no problems. I would not use self tapping screws and they tend to break the fiberglass and start cracks. A clean hole is round and smooth and won't crack out.

 

[debit.servus]

I just drilled about 30 holes into the high top of mine. Mounted solar panels, roof vent, and lighting. I was a bit apprehensive at first, but I can't see how this can be avoided to achieve a clean install of the necessary equipment that we all need.

If done properly and sealed properly, there should be no problems. I would not use self tapping screws and they tend to break the fiberglass and start cracks. A clean hole is round and smooth and won't crack out.

I do plan to drill pilot holes first before screwing the self tapping screw, is what I described a clean hole?

 

[Almost There]

While we're on the subject of high tops a couple of questions.

Are they all double hulled or did someone ever put out a single layer hightop?

The reason I ask is because the Ford I 'inherited' from parents 25 years ago had a double layer hightop that had insulation in between. Now with the Savanna, I'm not sure if it does and I can't find a manufacturers mark (probably find it under the crap that's in there right now).

The other question is what can be used to close and seal holes that are already in the hightop? There's a few things the previous owner installed that are coming out asap.

 

[Howiet]

I just finished installing solar on my fiberglass high top. To determine the thickness of the material I was dealing with I removed the interior trim from around the roof vent. In my case I found that I had 3/4 of an inch of plywood under the fiberglass. I drilled an appropriately sized hole for the screw to thread into the plywood and then relieved the hole in the fiberglass with a drill bit large enough so the screw would not stress the fiberglass as it passed through.

 

[SternWake]

Getting a sheet metal screw into fiber rglass is easy
but . Getting it to hold properly requires predrilling to the exact size. Check out some marine sites for screw size mating drill bit size.

Honestly. if you have done this before. I like the vhb tape and wood block idea. Fiberglass can be a female dog to a neophyte. Do not use a screw gun after predrilling. Hand tools for cutting threads.

Forget self drilling screws

 

[66788]

I do plan to drill pilot holes first before screwing the self tapping screw, is what I described a clean hole?

Personally I would not use any screws into fiberglass. The resin is not strong enough to be tapped, and a machine screw will only force the glass to stress and crack. Clean holes for a through bolt is all I do. You can use a machine screw with the head on the outside of the top, then a blob of Dicor will seal it well against the elements. The inside of that screw will be a washer and nut, thus not stressing the glass because it will be squeezed between the head of the machine screw and the nut.

---

While we're on the subject of high tops a couple of questions.

Are they all double hulled or did someone ever put out a single layer hightop?

The reason I ask is because the Ford I 'inherited' from parents 25 years ago had a double layer hightop that had insulation in between. Now with the Savanna, I'm not sure if it does and I can't find a manufacturers mark (probably find it under the crap that's in there right now).

The other question is what can be used to close and seal holes that are already in the hightop? There's a few things the previous owner installed that are coming out asap.

My 1989 Dodge high top is a single layer with gel coat on both the inside and the outside.

I would use fiberglass resin to seal the holes, grind flush when dry, and then seal with a light coat of your favorite roof sealer over the repair on the outside surfaces.

 

[concretebox]

When I installed the solar panel on my fiberglass hightop, I followed the suggestion I heard in this forum. I made wood backing plates for the inside. Rather than cut and pull back the ceiling carpet and insulation, I made the blocks look nice. See the photo. That's 1/4in oak plywood, stained and poly'ed.

On the outside, I applied Butyl Rubber to the feet of the solar panel mounting and around and on top of the bolts.

 

[Patrick46]

Your missing a point here Debit.Servus...

unless you're mounting something heavy and permanent, do NOT drill through the fiberglass. You're only asking for trouble. And self-taping screws are going to create a monster you don't wanna deal with.

Others have mentioned glueing mounting blocks on the inside of the roof. The crazy strong glues they have these days will work great for this. Check at an autobody shop. They'll give you ideas of whats available out there.

 

[itsnotliving]

I'll chime in here too. DO NOT rely on the fiberglass to hold a screw if it is going to have any stress on it. In particular one that does not go all the way through.

Drill a clean hole by taping the entry and exit areas to limit damaging the edges of the hole.

I also tend to think (and it is just a thought) that mounting wood blocks to the outside with glue then drilling from the inside into the blocks and then attaching your equipment to the wood blocks may be a better solution. This would likely seal the weather from the holes.

Damaged fiberglass, i.e. drilling holes in it (especially if older) is likely a problem waiting for an opportunity.

Do some research on fiberglass sites to see what they may suggest.

I would go for bolts rather than self-tappers.

If you decide to do this make sure the load is spread over several sq. inches per hole and follow the profile of the roof - flat washers are not good enough.

As with many similar situations there are many out there that have done this without mishap - yet.

 

[debit.servus]

What I thought of doing was fashioning metal rod(s) to securely drill the van body metal below the lip, no hi-top holes required. Fashioning two of these rods for supports one between bed and living space and one around the closet area would provide supports for various things. Has anybody fashioned interior metal support rods parallel to a van's high-top ceiling?

Besides, eventually after I get the functional mods finished I plan to cover over the insulation with some thin cosmetic paneling, a discussion for another thread.

 

[highdesertranger]

high tops are constructed in all manner of ways, single layer, double layer with plywood core, foam core, cardboard core. as someone else mentioned you can remove the trim piece around a roof vent. if it has windows you can remove one of the lower trim screw to judge the thickness. don't remove the whole window trim you will loose the seal on the window and it will leak unless resealed. as everyone has mentioned do not use screws to mount anything to fiberglass. you can laminate plywood to the fiberglass then screw to that or you can use adhesive or vhb tape. highdesertranger

 

[debit.servus]

What I thought of doing was fashioning metal rod(s) to securely drill the van body metal below the lip, no hi-top holes required. Fashioning two of these rods for supports one between bed and living space and one around the closet area would provide supports for various things. Has anybody fashioned interior metal support rods parallel to a van's high-top ceiling?

Besides, eventually after I get the functional mods finished I plan to cover over the insulation with some thin cosmetic paneling, a discussion for another thread.

Good reply highdesertranger, I plan to go with a bridging metal slat mount parellel to van's ceiling.

Has anyone done a metal slat mount for inside a high top van mounting it to van body ( the best I can describe using text)? I am thinking using metal akin to those L beams on bed frames? Like stregnth, thickness and size wise?

And I can be certain this vans high-top is a single shell.

 

[christine]

I like the idea of attaching wood to the inside of the fiberglass high top with VHB tape.

Here's another suggestion: use flexible plastic curtain track, and use VHB tape to stick it directly to the inside of the high top. I don't know how heavy your curtain will be, or what the inside of your high top looks like, but hey, it's an idea.

 

[highdesertranger]

if you are going to bolt though the fiberglass you really don't need angle iron. what I have used is aluminum flat bar. 1/8" thick x 2" wide. if you do it this way you must make sure the fiberglass will handle it, the type with the cardboard core will collapse if you try to sandwich bolt it. highdesertranger

 

[sassypickins]

I have several spring-loaded curtain rods that I can move anywhere along the ridge where van roof meets hi-top, but I have to duck to go under when I put one in the middle. To remedy this I bought some of the flat bar highdesertstranger mentions. But I'm not going to fasten it to anything, just cut it the right length to force into place from side to side so that it bends to the curve of the hitop ceiling. Once in place, it should stay. If I slide a hemmed curtain top through it first, I can cut the bottom of the curtain to meet the floor. Besides privacy, this should provide me some insulative warmth if I want to block off one area from another. Sliding the curtain itself once it's on the bar could be sticky and if so, I'll probably just tie it back.

I might build and install opposite lightweight cupboards up in the hitop, but want no holes up there. I'll secure them at their bases only to the existing 4" roof/hitop metal ridge edges and force a flat bar or two between them up at their tops. Again, there'd be an upward bend of the bars to keep them close to the shape of the hitop ceiling, and I'd have a lip on each cabinet top to keep the bars ends in place. Keeping to the principal of placing weight on or near the floor, these cupboards would be for lightweight supplies.

 

[66788]

I have no qualms about drilling holes in my high top van. When I mount my cabinets to both sides of the van, I plan on using screws from outside the van to the wood furring strips inside the van. A touch of Dicor over the heads of the screws will keep them watertight for years. My Grumman Olson step van has hundreds of rivets in the body and none have ever leaked. Those rivets are sealed with paint only.

The way I look at it is that it's an old van and I'm putting it to its highest and best use, and I plan on using it as I see fit and not worrying about a few holes.

 

[highdesertranger]

sassy that will work I have done before just make sure you get it good and tight. I have even done that method on my old truck with a fiberglass shell, that truck saw many many miles of off road driving never had a problem. highdesertranger