building a pop up camper box from scratch... as always 90% planning 10% doing

[Itsavanman]

still in the planning stages of a custom pop up camper top, anyhow the plan is to use ISO foam / wood / and fiberglass resin as the structure of it, want to keep it light, but strong enough to not fall apart on the trail from light to moderate abuse. got the structure planned out, however, I'm not sure what size wood I should use for the skeleton of it, something tells me 2x2's would be the best but not sure. the "bones" would be spaced out at 2' intervals on the sides and roof with 1" thick foam filling in the voids and 1 layer of woven roven cloth on both sides. I still think I am over-engineering this, but since this is my first build up, not 100% on that, it also will be removable, so want to keep it as light as i can. anyone care to share from their previous experiences? thanks folks!

 

[Capt Eddie]

If you are going to use 2 x 2 for the bones. use 1 1/2 of high density foam in the voids. If I were doing it. I would go ahead and plan on using 2 inches of foam. you will find that 2 inches of foam does have a structural strength to it. Almost no need to additional structure if you could make it out of all foam, then cover with fiberglass. The only place you might need support would be the roof.

 

[ripperj]

You would need some sort of blocking ( frame) around windows,roof vents, rack mount locations etc. Something for screws to bite into.

Sent from my Z10 using Tapatalk 2

 

[Itsavanman]

so as I said I will be using polyisocyanurate foam, as its one of the only inexpensive foams that doesn't melt when standard poly resin is used.. what density would that be considered? and this camper is going to be small, not letting the cat out of the bag just yet but the largest span will be the roof. I planned on laminating 1/2" "boards" to get the 1" thickness so I can go as thick as needed,

 

[Abitibi]

If your top isn't too large why not simply use 1/2" or 3/4" plywood with a layer of fibreglass on top and Gelcoat the whole thing? It's not as fancy as the foam lamination process but it's easy, fairly light, strong and cheap. Not sure of the R value but wood is a decent insulator.

I built a lid on my old M101 using this technique and it turned out great. That's also my backup plan for the poptop on my AmbuLand project although my opening will be approximately 5'x10'.

Cheers
Mr. D

 

[Itsavanman]

thought of that too, I think for as little foam as I need, I think it would be lighter and just about the same price as plywood.. the size of the camper is 4x7 is just sleeping quarters... gonna be pretty wild me thinks...

 

[soulpatch]

Why not use lightweight metal framing and make it easy? Bolt together and with the foam insulation adding shear strength it would seem to me, but I am me so take that what it's worth, that you would save many pounds and make it seriously easy to put together.

 

[Jfet]

Steel isn't too bad for framing, especially for a small camper. Easy to weld and strong as...well, steel.

We used 1x1 and 1x2 steel tubing in 0.063 and 0.125 wall thickness (only the thicker material for the overhang and corner studs).

We used iso foam and aluminum siding but wood would work as well.

Just measured the camper on the truck and the dry weight of the camper is 3200 pounds with all appliances installed but empty water tanks.

 

[Itsavanman]

I suck at welding, better with resin lol... had a brainstorm, looks like its just gonna be a pop top with no sides, pretty much copying whats on a westfalia at least on the pop part.. but with a few major differences, that I feel will make a very small vehicle work quite well for 1-2 day trips, pretty stuck on iso foam. If the total size of the top is 4x7x6-8" will i even need any side supports other than foam? here's a quickie design of what im thinking, i am thinking of laying the foam on top of this structure, all lines represent wood.

I could use more reinforcement, but not really sure if I need it...

 

[sfcruiser]

I'm building a poptop on an FJ62.
Base is 2" sq tubing
Top is aluminum frame with a nidacore top.
Still in progress

http://forum.ih8mud.com/threads/1990-fj62-weekender-poptop-build.769056/