Composite Camper Design for 3/4 Ton Dodge

[Nitromethane43]

Hello Everyone,


I am back in the process of working a composite camper body that will reside either on a first or second generation Dodge 3/4 pickup truck. The goal is to have a smallish camper with regular accommodations for two people traveling down to Panama, and beyond. I have tried to keep everything as close to the original footprint as possible, as it's been difficult in some places of Mexico driving the truck without a camper on the back.

The construction method would be a 2" structural foam core with fiberglass skins on either side, I have seen a few people go about using this construction method, one was with pink insulation board on a newer Toyota or Nissan truck and S2DM has made parts of his camper with this. It does take quite a bit of labor to get together compared to any panel system, but the budget does not work well using the prefab panels.

Here are some preliminary specifications:

Floor Length: 104"
Overall Length: 168"
Exterior Width: 86"
Interior Width: 82"
Exterior Height: 82" > May reduce to 76"
Interior Height: 78" > May reduce to 72"
Fresh Water: 50 Gal
Grey Water: 30 Gal
Solar Capacity: 640 Watts
CALB 400Ah Capacity Battery
2000w Victron Inverter Charger
Morning Star Tristar MPPT Charger
Blue Sea Systems Electrical Panel
Diesel Hydronic Heating w/ 11gal tank
Dometic Saneo Toilet
Nova Kool RFU8320 Fridge
Windows: Hehr 6400 or Motion Windows 1275

Below are some working concept drawings:



One of the possible contenders




Exterior View




Plan View




Interior 1




Interior 2




Interior 3




Interior 4




Section




Frame



If there is anyone with some advice I be pleased to hear what you have to say, some questions prior to going into the design stage are:

1. I would like to lower the overall height and have the interior at 72" tall, that works fine for me as there is still some head room, but does living in a camper with low head room increase discomfort over the long run? And does anyone that has a low camper wish for more head room after a short period.

2. What is a good working cab over clearance over a truck with a open C-Channel frame say earlier trucks without causing any rubbing issues while on rough roads, not any serious rock climbing, but say going over ledges or ditches.

3. All over on the RV forums people have complained about the Hehr 6400 flush mount insulated windows fogging up and being really expensive to fix due to the frame less design. Healeyjet seems to have chosen these windows for a build, is there anyone with experience on these windows, they look great, but do not want to spend a fortune on them and then have to fork over another to get them repaired when fogged up. The alternative is to go with Motion Windows 1275 Marine windows that are insulated but have standard frames and can be swapped out with 1/2" plastics if fogging becomes an issue.

4. For people that have gone the full composite route what form of attachment is used on the camper to chassis connection? I was thinking of glassing in two fiberglass rails on the bottom of the camper similar to stingers on a boat, then bonding them onto a steel frame which will get mounted to the chassis, it there an better method which could eliminate the frame and lower the overall height?

5. Has anyone come upon a good alternative to wood materials for the interior fit out and cabinetry, It would be preferred to not have any wood in this build, Corsa Board seems very expensive, Sintra PVC is a light weight contender, and Starboard is fairly heavy for full cabinetry.

 

[dlh62c]

Sounds like a fun project. The CAD work is always the easiest part of the job.

The body strength will be in the corner extrusions. What do you plan to use to connect the composite panels together?

Do you have a staging area in which to work on this build?

Have you considered sourcing a ready made Fiberglass Truck Service Body and fit out the interior to suit your needs?

 

[Maninga]

Sounds like a fun project, lot of work ahead if you're building the panels yourself. Might be worth sending a query to Victorian (member on this site) asking what panels would cost, between opportunity cost and all the little pieces which add up, might be worth it.

Couple of thoughts

1. I would like to lower the overall height and have the interior at 72" tall, that works fine for me as there is still some head room, but does living in a camper with low head room increase discomfort over the long run? And does anyone that has a low camper wish for more head room after a short period.

All depends on the person. I like having the sense of space but with low profile, so went hard sided popup. What would your headroom above the bed be like? Waking up in the middle of the night may be an issue if too low

3. All over on the RV forums people have complained about the Hehr 6400 flush mount insulated windows fogging up and being really expensive to fix due to the frame less design. Healeyjet seems to have chosen these windows for a build, is there anyone with experience on these windows, they look great, but do not want to spend a fortune on them and then have to fork over another to get them repaired when fogged up. The alternative is to go with Motion Windows 1275 Marine windows that are insulated but have standard frames and can be swapped out with 1/2" plastics if fogging becomes an issue.

No idea on the Hehr. Have a look at Outbound windows, I'll either be changing mine to these or using them on next build

4. For people that have gone the full composite route what form of attachment is used on the camper to chassis connection? I was thinking of glassing in two fiberglass rails on the bottom of the camper similar to stingers on a boat, then bonding them onto a steel frame which will get mounted to the chassis, it there an better method which could eliminate the frame and lower the overall height?

Steel subframe, composite glued on. Guys who built the body use a Henkle product, Sikaflex 252 would have worked too

5. Has anyone come upon a good alternative to wood materials for the interior fit out and cabinetry, It would be preferred to not have any wood in this build, Corsa Board seems very expensive, Sintra PVC is a light weight contender, and Starboard is fairly heavy for full cabinetry.

Composite panel maybe?

 

[ripperj]

Neat project, just a couple thoughts:
Do you need the marine version of the Motion window?, it's probably pretty heavy, I was going to get their high end double pain RV windows and ended up with single pane for weight and thickness(thickness won't be an issue in your build)
Even the single pane version I got is surprising heavy, but a very nicely built window. Mine are still in a crate, so I can't speak to durability, but can't imagine they won't last, very high quality.

The second thing is 50 gal of water will eat lots of available payload on a 3/4 ton truck, I understand you probably need it where you are headed, but something to think about. Maybe on board rodi/uv magic whatever filters??

Sent from my Passport

 

[LukeH]

Hi, GO FOR IT!
1: Go hire a vanagon for a few days and see what stooping is like. Why lower? the box is empty, so if the roof is just a tad higher it makes no weight/rollover difference It's only wind that'll be an issue, but you can park facing it.
2: if you have your two fixed points right behind the cab you're not going to have much swing and could get away with very little clearance. Do a test: put a full 200gal drum in the bed for ballast, strap an open step ladder across the bed and strap a couple of 2x2 beams pointing forward. Go and wave a wheel and see how bad it is. You could even put a board between them. You'll see for yourself.
3: I'm in Europe, couldn't comment except to say you don't have much choice over there. I'm hoping sonn to develop a PVC framed double glazed window with tempered glass for road use and less expensive than what's currently available, but that'll be a moment yet. In the meantime there's always http://www.outbound.eu/en/windows.php
4: You're going to have to use metal at some point. If you're making up your own floor panel you can mould a tubular steel frame into the floor and then bolt into that. Think about making it demountable; you lose a lot of potential buyers if the truck can't be returned to original, and if the body can't be swapped easily to another base if a buyer wants something more modern/bigger/older/etc. or ifever it's no longer economical to fix.
5: If you're able to make up your own panels just do the same for the furniture. You can gelcoat them the colour you want, bond them in knowing they become part of the structure and you don't have anything else to source.
You have to slog through this thread, there is a hell of a lot of good info, practices, tips and lessons learnt the hard way in there http://www.expeditionportal.com/forum/threads/45835-C5500-TopKick-4x4-Crew-Cab-Build

Do it! Enjoy it! Keep us posted

 

[LukeH]

Two seconds with google popped up this :http://nashville.craigslist.org/hvo/5360390538.html
You could chop the panels out of that for your sides, floor and roof, with lots of spare.
Obviously you would probably be able to find less expensive nearer to you.
It's what I'm doing; best insulation, tough as hell for commercial use, cheap, easy to find.

 

[S2DM]

I would echo what others have said and see if you can find panels before making them. We bought a small quantity at the start, then ran out and needed to start making panels. We were also forced to because we have curves in our camper that required molds etc. That said, its just alot of smelly, itchy, messy work, and requires a biggish work space. The number of times Heather wanted to kill me during this project has increased exponentially with each new panel I've made The panels Victorian is making look great, and in the end, are probably cost effective compared to making them as well. There are tons of little things you need that really start to get expensive over time. Ours is an outlier, and I like how it looks now and we couldnt have achieved that another way, but....it wasn't cost effective, not by a long shot.

Couple thoughts on making panels, I'm happy to do a phone call as well if you want to go over it.

1) Will need to use a structural foam, I.E. Divinicyl h80 or similar, roughly 5lb density. Its expensive, ~$200 per 4x8 sheet for a 1" thickness, not sure on 2". But its really important to use a foam that is structural. I dont have a great physics explanation for why it is so, but strength comes from thickness. You could take 10 layers of 1708 glass and layer them up on each other, each layer is about 1/16, so you'd end up with a 5/8" panel, heavy and all glass. If you do 2 layers of 1708 and stick a 1" foam core in, it would be stronger, despite having 8 layers less of glass and a fraction of the weight.
2) I like hexmat, knytex, 1708 or similar, which is a 17oz biaxial woven mat, with a integrated chopped strand backing. The chopped strand backing is applied to your substrate and the woven forms your outer skin. Fiberglass bonds are interesting, its a combo of a physical and chemical bond, that chopped strand kind of dissolves in catalyzed resin, and gets its hooks into all the nooks and crannies of the substrate. With a non roughed panel and no chopped strand, you'll occasionally see woven mat just pop off. So you really need to have CSM as a backer, and using a cloth that has both integrated makes it easier.
3) You'll need some sort of large, very flat table, with a non porous surface. I've found melamine with a release wax put down first works really well. Fiberglass shrinks as it cures, so its important to let the panels stay on the table for a day or so afterwards, or make sure to put them on a flat surface afterwards. Ive seen well made panels develop a bow really easy the day after they were made.
4) Every thing you need for panels from a binding perspective can be made with resin, but you'll need to get the resin and additives in bulk. Don't go cheap on resin, you'll regret it later, but you also dont need to go all the way to vinyl ester for panels, save that for any secondary bonds. A good isothalic tooling resin is a good starting point. You'll need to make a putty at many points, which can be made by adding cabosil/fumed silica to the resin until it reaches desired thickness. Putty is brittle on its own, so when you need structural putty, I.E. for putting in mounting surfaces into the panels, a piece of plywood or garolite, make the putty with milled fiberglass fibers (not chopped fibers, milled, looks like powder, but is tiny bits of glass). It makes the putty very strong. For binding skins to panels, you need to make a lightweight putty. Cabosil only thickens, its doesnt increase volume, so for this you add 1/3 microspheres/qcell and 2/3 cabosil. Trowel the mix on after catalyzing and then vibrate the panel down. Likewise, qcell lightens the mixture and makes it sandable, so use that whenever you anticipate needing to shape it afterwards. You can play with these mixes to get the desired properties for any given task. I wouldnt hesitate to use wood in place of foam in areas where you need extra crush resistance, need to add an anchor point, etc. You can putty wood into the foam before adding the skin. The wood soaks up the resin and becomes very water resistant. Just use a really high grade ply like apply ply or baltic birch.
5) You'll need something to final cure the resin, either surfacing agent or peel ply/release fabric. Resin is air inhibited, it doesnt fully cure in the presence of air. So the outermost layer will remain gummy and just destroy sand paper. After wetting out your cloth, if you add surfacing agent to your resin mix and apply one more layer at the end, the wax in the surfacing agent will rise to the surface and seal the resin, allowing it to cure. Release fabric is awesome, but gets expensive if you are using in bulk. It works on the same principle, but due to the porosity of the fabric, it leaves a stipulated surface afterwards which is perfect for priming or rebonding. It also somewhat forms the resin during the cure, and just leaves a much cleaner final surface that requires less sanding.

Last thought,

If I had it to do all over again and were determined to build panels myself, I'd consider spending the time to build a 2 part mold. Basically, build a mold with melamine of 1/2 the camper and use that to make a monococue panel that is 1/2 your camper. Split your design down the middle from front to back, and build it in two parts, then join them at the end. You could use most of the mold over and just switch which side the side panel melamine was on. Joining panels, I.E. making a bunch of flat panels and then joining with secondary bonds to make a structure is a ton of work, a ton of sanding, and not as strong. Personally, I'm not a fan of gel coat, but if you were to use it, you put gel coat down first, then your glass in reverse orientation. Let it all cure, then start puttying in your foam piece by piece. Once that is in, another layer of glass and then take the mold apart and you have a 1 piece shell. And its already got a gel coat on the outside and is smooth. If not using gel coat, you can put chopped strand down first, then a layer of glass. The chopped strand will dissolve and leave a really nice smooth outer skin.

From a guy who has built a ton now, you really want to keep an eye towards what will keep you from sanding afterwards. The mold is a bunch of up front work and requires meticulous planning up front. But it cuts out a ton of sanding.

Happy to chat more if you decide you want to go forward with panels.

 

[Freebird]

Commercial truck and trailer salvage/wrecking yard might be a place to source large sheets of high quality composite panels.
It is used extensively in 18 wheeler trailer/van walls, and those drivers do have wrecks all over the country....
Sourcing there might be reasonable and give a leg up on your project.

 

[Healeyjet]

Nitro, I am not sure, had I been building the camper myself, that I would have chosen the Hehr windows. ITB, the company building it uses them all of the time and they are located in Canada so I am hoping they have the fog part dialed in. If not they are under warranty and when that runs out I will consider their performance and options.
Had I been building it myself, I would have gone with a window like the Outbound. The Hehr don't open up very wide. I like a window that opens up whereas the Hehr only a small part of it opens.
Ward

 

[Nitromethane43]

dlh62c:

I have worked out of a truck cap similar to the following while in Canada, but it seemed really cramped, but that may be due to the workbench and materials shelving inside. They seemed to be built fairly well, and can be spotted all over the place up north, not as much in the states for some reason.

It will be a full glass body without any extrusions.

Maninga:

I would try to keep at least 30" above the bed, especially if the cab over clearance can be reduced then dropping the overall height is not a problem. It would nice to keep the overall height under 120" with a 35" tire that may still be possible, but 37's would be over.

The Outbound really sharp, especially with a security cover option.

Adhesive was going to be Plexus, but a similar bonding procedure as a Sika product, I have seen first hand how well that adhesive will adhear on a metal to metal bond its amazing how adhesives have evolved.


ripperj

What version of the motion window did you purchase? And do you have any images of them?
I was talking to them and the top hinge marine version was the only one with a awning style with insulated glazing that seemed to fit the application. Plus the glazing could be exchanged for something 1/2" thick, including wood if things get broken on the road.

50 gallons is heavy, but I currently have 100 gallon fuel capacity in the red truck, when a long haul is up it gets filled and no worries for many miles, but when not needed I can always put less, sure beats Jerry cans on the side of the road, while having assurance of clean fuel and taking advantage of price shopping. The water should be the same, it just happened that a off the shelf 50 gallon tank fits under the seating area.

The idea of going with a 30 gallon tank with ozone injection in the tank and uv at the tap did come up, I still may add those two features if a small unit is sourced, http://www.konaozone.com/main.php?fid=201&page_name=detail&prod_id=101 seems interesting, there is very little information how they do with unknown water quality and testing to back up the claims.


LukeH

Some testing still needs to be done, my single cab truck twisted a lot while climbing hills, but I would not attempt that with a camper.

Good luck on the window development, hopefully there will be a middle ground someday between cheap plastic windows and the high end units.

I am not too sure how swapping between different chassis will come about especially across different manufactures, at least its being built for a pickup chassis with wider rails so a commercial or straight frame transplant would be possible in the future. I have both first and second generation Dodges, and the subframe would clear both, just the second gen has rivets in some areas where the multi piece rails were put together from the factory. That is good insight, if only there were more options for good mechanical diesel truck


S2DM

Your build has been good insight on going through this construction method, it must have been a chore going through multiple locations during one build, wish the best to your completion.

Once the final parameters have been nailed down I would love to chat with you about the process and what went on.

1808 was going the be the preferred reinforcing material with epoxy, waiting on a shipment to lay up some test panels using some 3# foam, if not sufficient then 5# may be in order. In the past for not structural applications layup over 1# have been a lot stronger that what one would have imagined over the soft stuff. Below is a small piece,




For assembly the intent was to laminate 8 panels being top, bottom, sides, ect on a flat table inside and out, then do secondary bonds to make the box, like you mentioned this would reduce the amount of flairing and sanding afterwards. People have mentioned that http://www.flexicat-usa.com/ tools work wonders when fairing boats, have you tried something along those lines to help out on smoothing panels out?

Now mostly through a build, would you have considered a mold for an one off build too?


Healeyjet

Now that you mentioned Hehr is not the preferred choice it may be back to more research. I just saw a lot of commercial manufactures using them, and you also mentioned it in your build so they were considered.

To Everyone, the insight has been very useful and keep them coming. Hopefully more problems can be worked out prior to fabrication.

 

[S2DM]

That powered flexicat looks cool for sure. We honestly didnt have enough big radiused surfaces to justify it, but I want one nonetheless

I do most of my big radius work with a basic Milwaukee sander and a really thick soft pad that conforms to the surface

https://shapersupply.com/collections/power-tools/products/milwaukee-sander

But far and away the tools I've used the most are the festools. Get a good festool vac and a ts55 or ts75 track saw, along with the 106" track (Id consider the long track from festool a must unless you have cnc access). The other thing I *highly* recommend is the RAS 115

https://www.festoolusa.com/power-tools/sanders/ras-11504-e-rotary-sander-570789

Its an absolute beast for prepping surfaces for secondary bonds and has pretty decent dust collection for how quickly it chews through material.

I also use the festool rotex 90, and a mirka deros. The rotex is also a beast, and its nice to have a smaller pad for some work. I love the deros, but for this build I would have gotten more use out of a rotex 90 and a rotex 150. But, the ras has been indispensable.

In answer to the last question, definitely. I've learned a bunch through the process, but I wouldnt do it this way again. At a minimum, I'd make a basic mold. Melamine for the bond surfaces, with ply stringers for reinforcements on the outside. Get some inside radius trim, paint it and wax it and use it in all the corners. It may seem like more work upfront, but you'll have stronger corners, and much less sanding. If not, bond with pultruded extrusions like they did in the topkick build. Pricey, but strong. Next, I would use aluminum and sika 252/3m 5200. Different thermal coefficients of expansion make this approach slightly more leak prone, but it is also very strong. Last, I would do secondaries like I did. The secondary bond approach is just a ton of work.

Last comment, I wouldn't bother with epoxy for the panels, use iso or vinyl ester. IMHO, epoxy doesnt buy you much in panel construction. It also limits you to using only epoxy from that point forward. Use it where you need it, and stick to poly/vinyl for the basic work. Epoxy sticks to anything, but only epoxy sticks to epoxy. You'll have more tools at your disposal and an easier time in your day to day if you start with poly.

 

[Victorian]

Agreed with the Festool. Been using them for many years. Although they are slowly getting out of my price range.... Those yearly 10% price increases are insane.

 

[Healeyjet]

Nitro, the Hehr windows wouldn't have been my choice simply due to the opening factor. I haven't read the negative writing about fogging that you have but to be honest once ITB said they would be using the Hehr windows and they liked them I stopped researching.

If you choose to build your own agree with the guys above. I have Festool saws etc in my woodworking shop and wouldn't want to use anything else. They work so well.
Ward

 

[ripperj]

I went with the "Elite Series 1600"
These are slide type windows, so only 1/2 opens. Motion has a simple worksheet that you fill out for size, frame color, tint etc.
The window can slide up/down or left to right.
They have nice latching hardware and screens.

I'm not trying to push Motion on you, I'm just a real picky consumer and my Motion experience was one of the few transactions that I was totally pleased with, even their shipping crate was impressive.


http://www.rvwindows.com/products/rv-elite-single-pane-windows-series-1600/

This is the only pic I have, not too much help. I will be installing them soon and can send pics then if it helps you.

Keith

Sent from my Passport

 

[Nitromethane43]

There is no push motion was already one of the ones that seemed to have a decent product, they are the ones that suggested the marine top hinge as they open as an awning style and have a strut arm supports. I am glad that you have positive feedback on the company as I have never ordered vehicle windows from them, but One day glass has delivered many insulated glazing units for building windows on time and in one piece in the past, they seem to be the same company.