DIY Composite Flatbed Camper Build

Terra Ops

Adventurer
Jeff,

FWIW, Nimbl routed the urine line to the grey tank. The logic being that:

-- Diluted urine is a lot more palatable than concentrated. (I don't want to think of dealing with a dedicated "Yellow Water" tank.)

-- In most cases, you are required to dump grey water into a sanitary sewer anyway, so adding urine changes nothing.

I confess that I like the idea of not having to dump urine every day. Keep me posted.


In my case, things are a bit harder as all of my grey water goes through a shower sump and pump.

Fred,

The plan is to make an additional "P tank" which replaces the current one. This new tank will have a valve for draining externally when
needed. It will also have a quick disconnect when using original tank.
Still working on plumbing route from camper through pocket in flat bed.
 

DiploStrat

Expedition Leader
Fred,

The plan is to make an additional "P tank" which replaces the current one. This new tank will have a valve for draining externally when
needed. It will also have a quick disconnect when using original tank.
Still working on plumbing route from camper through pocket in flat bed.

Need to see a diagram. Diverter where the P tank sits and then a new, larger tank remotely? Or merely a drain?
 

Terra Ops

Adventurer
Need to see a diagram. Diverter where the P tank sits and then a new, larger tank remotely? Or merely a drain?

Still need to make the base and plumb.
This tank replaces the original. Blue hose leads outside under truck.
 

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Terra Ops

Adventurer
Made the base to fit inner contour. Stays in place nicely.
Still have yet to drill hole through floor to external tank/drain field.
 

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Terra Ops

Adventurer
Day trip to give the rear Icon shocks a little more testing. They did not disappoint. Hoping to find the front available soon.
 

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mnjoe

New member
awesome build. thanks for all the detailed information,

similar to others i have been researching panel construction. i learned about Azdel panels that are widely used in RV construction. an interesting discovery is their testing method of panels. it may be a good idea to adopt some of their testing methods. the peel test could really help compare and quantify the various methods for laminating panels e.g. adhesive, thickness, etc. here is a link to the manual peel test, easily duplicated for our use, maybe a 4" PVC pipe section with the ratchet attachment? you can see they clamp an unbonded section of panel to the drum then rotate.


also, i have had some luck finding local sources of panel through the truck and trailer supply shops. the most common product is Kemlite. they have a roll stock trailer roof panel that is applicable. the roof should have UV protection. they also have wall liners but it is less commonly in stock at suppliers.


another FRP supply option is NUDO. they sell through building materials suppliers. it's possible to order their roll stock through the suppliers. they have lots of panel types and sizes. Fiberlite seems to be a good match. unsure about UV protection


thanks again and magnificent work!

joe
 

DzlToy

Explorer
The roll test is interesting, for sure, but what you will find when using foam core in sandwich panel construction is the foam itself is the limiting factour. You can have the best bond in the world between your carbon, Filon or alloy skin and the outermost layer of foam, but the next "layer" of foam, e.g. 1mm down into the core, will simply pull away from the other foam around it. You will then be left with a skin having some foam attached to the backside of it and a failed core. It is for this reason that structural foams, such as those made by Gurit and Diab, are used in aerospace, marine and transport applications requiring strong cores. Nomex, Hexcell and Plascore are also options if foam does not meet your needs. For a small camper, non-structural foam is likely acceptable, but, at the end of the day, it was designed to be insulation, not sandwich core material.

When a weak, or inappropriate core fails, and it will eventually, the skins are not strong enough on their own to support the load and the sandwich panel will buckle. Thus, a core with a high tensile and compression strength is ideal. For those interested in building their own panels, I suggest doing some research on the various core and skin materials and making yourself a spread sheet or Word document with the various datum.
 

Terra Ops

Adventurer
The roll test is interesting, for sure, but what you will find when using foam core in sandwich panel construction is the foam itself is the limiting factour. You can have the best bond in the world between your carbon, Filon or alloy skin and the outermost layer of foam, but the next "layer" of foam, e.g. 1mm down into the core, will simply pull away from the other foam around it. You will then be left with a skin having some foam attached to the backside of it and a failed core. It is for this reason that structural foams, such as those made by Gurit and Diab, are used in aerospace, marine and transport applications requiring strong cores. Nomex, Hexcell and Plascore are also options if foam does not meet your needs. For a small camper, non-structural foam is likely acceptable, but, at the end of the day, it was designed to be insulation, not sandwich core material.

When a weak, or inappropriate core fails, and it will eventually, the skins are not strong enough on their own to support the load and the sandwich panel will buckle. Thus, a core with a high tensile and compression strength is ideal. For those interested in building their own panels, I suggest doing some research on the various core and skin materials and making yourself a spread sheet or Word document with the various datum.

Sounds like you have some experience. Care to share a recipe?
 

DzlToy

Explorer
I am happy to share my research. I have hundreds of pages of notes, emails from suppliers, technical PDFs and calculations. I have built and sold one box using a factory made panel (EPS core skinned with fiberglass impregnated with a phenolic-based resin) and have experimented with various other cores and skins in an effort to come up with a good quality, DIY friendly recipe. I would not use those panels again, knowing what I know now.

As someone with an engineering background, it is easy to get lost in the details, research until the wee hours of the morning and end up with 50 different ways to build a camper, boat, trailer, tiny house or whatever your heart desires. This is where it gets slippery. You get what you pay for. CAN you build a camper from canvas, Elmer's glue, plywood and old tarps? Yep. Will it be nice? Nope. Will it keep the rain off? Maybe. Will you have to rebuild it at some point? Most certainly.

There are so many factours to consider, namely weight carrying capacity of your vehicle, time frame, skill level of the builder, climate, space to work, budget, friends that can help, just to name a few. Resin is weak, carbon and Aramid are strong. Fiberglass is decently strong. Insulation is cheap, but not really that strong. "Stronger" insulation, such as Foamular 600 or 1000 is really expensive in small quantities. At that point, the slippery slope begins again, and "for a little bit more money" you can buy Plascore, Divinycell or Gurit foam. Fiberglass is cheaper than carbon, so the same rule applies. Is it really cheaper if you have to use twice as much of it or do twice as much work? Ditto for vinylester or other non-epoxy resins. Epoxy has a high price for a reason. It is the best. It is not "expensive" because you are getting a superior product. People have been conditioned to buy price, not quality or longevity or to buy their own time back. If you don't need H80 Diab, epoxy and carbon, what do you need, fiberglass, vinylester and Foamular 150? What do any of us really need? What do you want out of your camper? You asked for a recipe, so I will give you four. Disclaimer: I am not a composites engineer. This data is worth what you paid for it.

Super budget, wood based, not advisable: EPS/XPS foam core and 1/4" plywood skins glued on each side. Insert blocks of wood into the foam where you need to through bolt or mount stuff. Epoxy, bed line or Amercoat the whole thing after you have caulked/sealed all seams with concrete crack filler. A 1" thick foam core, plus a 1/4" skin on each side gives you a 1.5" thick panel with an R-value of 5. Wood campers are heavy, flimsy and do not last long without LOTS of work, and at that point, you could have just built something far superior.

Budget/DIY, decent quality: ACM, Filon, sheet aluminum, Celtec, Phenolic or other sheet good that can be used as a skin, so as to eliminate wet-laying cloth. Use Foamular 150 or 250, lightly sanded for the core, mix up resin roll it on the core, lay the sheet skin down and roll the air out. Do the same thing on the other side and you have a half decent sandwich panel. Rinse and repeat, sealing the edges and corners of the box by wet laying fiberglass or bonding on thin, aluminum angle pieces. Layering or stepping your core creates window and door openings and flanges. This can also be accomplished using a router, but you will need to seal the exposed foam or wet lay cloth.

DIY, good quality, more work: S-glass, carbon or Kevlar fabric (they aren't as expensive as you think), over a Polypropylene Plascore sheet core. Get the real stuff with a veil/scrim, not Chinesium. Repeat the process above by laying 2-3 layers of 200 GSM/6 ounce twill cloth in different directions and rolling/brushing epoxy resin into the cloth. There are tutorials on line. This method is a bit more labour intensive, but the skin bonds with the core better. Additionally, you have strong, light skins and a structural core, not wood over insulation sheets. Cheap roving, CSM and e-glass are not really good options in my opinion.

DIY/Best Quality, more money, but much cheaper than a Bliss box: Purchase Nomex, 5052 Plascore, Divinycell or Gurit foams in the 5 pound density range. Three layers of 3K carbon and 1-2 layers of 3K Aramid on each side create nearly indestructible skins/panels. The advantage of all of these cores is that they are so strong, you can use less of them or use a lighter weight product without losing strength. Example: (made up) - a 2" thick panel made with 1/4" plywood and XPS may have the same tensile or flexural strength as a 1/2" thick panel made with 5056 Hexcell core and three layers of Aramid. You just cut the weight of your panel significantly, freed up space in your camper by using a thinner core, saved on shipping, panels are easier to handle, blah blah blah. You have to look at the big picture, not just, "This costs $100 on Amazon or Alibaba or at Harbour Freight." INVEST in your time, tools, materials and camper box. Cheap men make for cheap goods. Personally, I have held off on building a camper because I want to do it right, once, not build something over and over or go use it and find a bunch of "should-haves". Save your pennies, shop around, collect parts over time, build with a buddy, etc.

Wet layup is easy enough to DIY; watch boat building and surfboard building videos. To make straight flat sandwich panels, a mould or large flat/true work surface is ideal, especially if you are making large panels with Nomex or Hexcell, as they aren't as rigid as foam sheets. Don't cheap out on materials, go slow, take your time, find good suppliers, negotiate, do not use wood or screws or spray foam or anything that can fail and screw up all of your hard work.

Skin thickness: A few layers of 3K or 6K carbon are hell for stout. Top with a layer of Aramid for abrasion resistance or spray the exterior with a two-part Polyurea. Fiberglass 'gives' a little bit; carbon does not, but this really isn't an issue a small truck camper.

Core thickness: Structural cores give up R/U/K-value, as they were not designed to be insulation. So, you should use another product that is design to prevent thermal transfer. Don't try to find one product that does everything. You will be left with a product that does nothing well. A REALLY well made sandwich panel, an inch thick will be incredibly strong, and leave room for insulation, interior finishes or external radiant barrier coatings. Many European builders construct 30mm and 60mm thick walls using fiberglass and XPS foam. Boutique companies such as KCT, make windows and doors to suit these walls.

I put a bid together for a potential client a few years ago, who wanted a simple, flat bed camper. I encouraged him to use sandwich panels made from carbon and Plascore instead of aluminum tubing and skins, but he would not go for it. Materials and a bit of profit for me was in the 10 grand range and dry shell weight was in the 400 pound range. There is no good reason for anyone to have a truck camper made from wood or one that weighs thousands of pounds, IMO. Well, there is, bad design.

If you are willing to remove the bed of your pickup truck and move some things around on the frame, the same techniques described above can be used to fabricate in floor water tanks, shower pans, steps, storage and battery boxes and so on. This adds little weight, increases overall rigidity (you are building a monocoque) and eliminates, "bolting a box or bracket to the bed/frame" in 10 places around the vehicle. Think live well in a boat or built in seating in a boat.

Sorry for the long post, but we are just scratching the surface here. This really is a rabbit hole. Order samples, do your own testing, experiment to see how varying materials behave in your climate or to see if they will fit your needs. There is no such thing as the perfect panel or the perfect camper.
 
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Terra Ops

Adventurer
Thanks for sharing your research....
Been thinking about your last comment; "There is no such thing as the perfect panel or the perfect camper."
So true and there never will be as tech improves and we are always striving for "better". Some of us can never be content as we "want" more and more.
In 2012, my family of four experienced our first camper. It wasn't perfect for various reasons, but it brought adventure and a closeness to our family, not to mention
many memories. The camper in this thread is our third rig. It too has brought many adventures and memories, and yes I have been thinking of building something different
with "improvements".
This past April we lost our daughter unexpectedly. She had just turned 22. The loss has been overwhelming, life has forever changed.
I share this so that those who are waiting to build or buy the perfect camper keep in mind that its not the camper but what the camper brings to your life.
I will forever cherish those memories of adventure and family. Everything in this world is temporary, make the most of it while you can.
 

Jonnyo

Observer
Thanks for sharing your research....
Been thinking about your last comment; "There is no such thing as the perfect panel or the perfect camper."
So true and there never will be as tech improves and we are always striving for "better". Some of us can never be content as we "want" more and more.
In 2012, my family of four experienced our first camper. It wasn't perfect for various reasons, but it brought adventure and a closeness to our family, not to mention
many memories. The camper in this thread is our third rig. It too has brought many adventures and memories, and yes I have been thinking of building something different
with "improvements".
This past April we lost our daughter unexpectedly. She had just turned 22. The loss has been overwhelming, life has forever changed.
I share this so that those who are waiting to build or buy the perfect camper keep in mind that its not the camper but what the camper brings to your life.
I will forever cherish those memories of adventure and family. Everything in this world is temporary, make the most of it while you can.


i love this thread as it as bring so much idea and knowledge that as help me think of the ''next project''. But even more important is the message you just past. it will never be perfect and we will always want to improve on. But the memory and moments it bring us as a family is precious. My son as a degenerative disease and we get to go out a lot camping. we enjoy the now, i will never miss on a camping trip because the project isnt done. i prefer making things a little cricked and unfinish and unperfect if it mean we are out on the weekend to pass time all together. Sorry for your lost. Cherish those amazing memories.
 

DzlToy

Explorer
As I was going through some panel notes today, I came across this PDF. It was produced by a well known European foam manufacturer called Gurit, with a US HQ in Michigan. Their foams are widely used in the yachting industry and are priced accordingly. However, there is much to be gleaned from this world, yachting, so an interesting PDF is attached. Pay special attention to the application for various foams, as well as common failure mechanisms for sandwich panels.

I have also attached a PDF from Plascore, also in Michigan, detailing sandwich panel construction and properties such as compression and flexural modulii as a function of core thickness.
 

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Terra Ops

Adventurer
Good information, thank you. The failure mechanisms are interesting and should be understood when constructing. I think that bonding interior structures to the overall "box" increases overall strength and minimizes panel failure as well as suspension to reduce flexing.
I have not had any failures with my home made panels. There were a few "bubbles". After window and door placement they are not as noticeable and seem to be solid.
The most important feature next to strength is R value. This is what I enjoy about our rig. It obviously allows any weather camping and minimal energy to maintain desired temp.
Does anybody know if polyurethane based adhesive instead of epoxy is a viable bond for panel construction? I have done some testing and am encouraged with the results.
I guess you could always buy premade. GXV offers a DIY kit. I would rather go this route than have the ones from China.....
DIY - GLOBAL EXPEDITION VEHICLES (globalxvehicles.com)
 

DzlToy

Explorer
Obviously epoxy resins are preferred, but millions of boats are made using cored "panels" with vinylester or polyester resins. You have to get into mega yachts, racing airplanes, million dollar go fast boats and America's Cup level stuff to find an OEM using exclusively carbon fiber, Nomex or Hexcell and epoxy resin. I viewed an interview last night with the founder of Nor-Tech boats and was surprised to hear they are still using solid fiberglass bottoms in most of their boats. Something like Corecell-M with Kevlar over it would be far superior in taking the pounding or slamming that an offshore 'cigarette' boat sees. This of course, is not an issue when constructing a camper, so lesser materials are less concerning, IMO.
 

DzlToy

Explorer
How carbon fiber + honeycomb panels are made and some of the differences between Nomex and Hexcell are highlighted in this video:


OP: PM me if you don't want this in here and I will delete it.
 

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