Impart on Me Thy Wisdom: A Newbie's Cry for Help

[stamati]

Howdy folks. I'm about to take on the task of building a new camper for my truck- no, it isn't a teardrop, but hopefully you'll appreciate it and offer guidance despite my blasphemy. I'm excited about the design and a foamie construction seems the most appropriate in terms of weight savings (my truck is weak). I'm really grateful for the huge supply of information here.

This is the Om Shanty's imgur album:
http://imgur.com/a/f5noc

Some questions to start:

I'm considering framing this in 1 x 4 Cedar, doing a PMF skin on the exterior and 1/8 plywood for the inside. Cedar is light, but I don't know how structurally sound it would be for this design. I'm really in the dark on this subject and I don't want to screw it up, basically. What would be the lightest material I could use and still have a structure capable of handling the stresses of traveling down the highway at 70mph?

The 4ft long cab-over is another question mark. Can I make it sound enough to handle two adults sitting on it? Again, I'm just making educated guesses here on what would work.

Any advice, input, inspiration is more than welcome!

Cheers.

[me&z]

Have you looked at seanc's foamie truck camper? He's got quite a few miles on it and it may answer some of your questions.

http://tnttt.com/viewtopic.php?f=55&t=64361

[stamati]

Thanks for this! His build is rad and pretty similar to what I've got in mind. It's hard to believe that something that is mostly foam can be so strong....

[GPW]

QUOTE: “ It's hard to believe that something that is mostly foam can be so strong....” Not to worry , that seems to be a problem for a Lot of people ...

[KCStudly]

Cedar and foam with skins is super strong, and can be built very light.

Although my build thread is rather long winded (and the first part is all about making the trailer frame), you might still find some insight there. TPCE is based on minimal frame work of 1x and 2x2 cedar, 1-1/2 thk blue foam, 5mm marine ply inner skin, and 2 plies of 6oz FG/epoxy outer skin. My original plan was to use canvas and paint for the outer skin, and I had a really hard time deciding to go with the FG. My testing showed that PMF was very close in performance to the glass/epoxy.

When you ask if 1x4 cedar would be adequate for framing, I would argue that it is probably overkill for most of what I am envisioning. The skins do most of the work. You can easily support the cab over with 1x on edge embedded into the side walls to transfer the cantilever loads from the sleeping deck. The skins in the wall extensions will also carry a good portion of this load back into the main section of the wall. The 1x on edge more or less becomes a reinforcement for the inside corner. Now the question becomes if a 1x4 is adequate. My TLAR sense of reasoning and experience with my build so far tends to think it would be, but that is really just a guess. To put it into perspective, I used 2x2 for the perimeter of my floor, the wall sills, and around the doors. 1x2 for roof spars, except 2x2's at the vent opening. The only 1x4's I have are let in for the fender mountings (mostly because I wasn't sure how high they would end up) and where the bulkhead wall attaches to the side walls. And I am probably (no definitely) building heavy by foamie standards.

Everywhere else I would say you only need enough wood to provide purchase for whatever screws you might need for any mechanical joints that facilitate construction, and of course where ever you need blocking to mount "stuff". If you plan well these can be combined, but it isn't that hard to let in smaller pieces of wood here and there where needed. The hardest part is knowing in advance where you want to put things that need blocking (... and getting thru the tedious process of installing all of them ).

[stamati]

Rather long winded indeed! It's practically a novel, or maybe autobiography. It's also an amazing resource. Thanks for the guidance- I feel more confident that I'm heading in the right direction.

[KCStudly]

No problem.

[seanc]

!!!FOAMIE TRUCK CAMPERS UNITE!!!


Really looking forward to this build

If you haven't already, I would read through this entire build: http://fordrangercabover.blogspot.com/2012/06/ford-ranger-cabover-build-day-1.html?view=sidebar
It was inspiration for me, and its even closer to what you're building.

As far as 1x4's go, if you're not sure they'll be strong enough for the cabover, bump up to 1x6's, it's very little weight increase for the gain in strength/stiffness. There might be some gymnastics going on up there. Better safe than sorry.

I'm really curious about your tailgate extension.

Will you be building a floor to the camper?

Also, I'd recommend going to home depot or lowes and playing with some aluminum angle. It's expensive, but its sooooo light/strong, and once you get your hands on it you might find some inspiration to use it in the cabover. if you can afford it. In fact, go to home depot and play with everything. There are so many building supplies out there that you just don't know about until you see them in person.