Custom truck camper, let's talk materials

[eugene]

I always wondered why someone couldn't take a large sheet of thin steel or aluminum and bend to shape just like the way the vehicle body is made.

When I was rebuilding our camper I used wood 1x with doweled joints and water proof glue. Each side I made solid and then used liquid nails to glue 1/8" plywood to the outside and inside. So it basically made a real solid structure like a torson box. Then the back and front bolted to the sides so there was a little bit of flex for when needed. I was then going to fiberglass the outside.

 

[rruff]

I always wondered why someone couldn't take a large sheet of thin steel or aluminum and bend to shape just like the way the vehicle body is made.

Cars are made that way because it's cheap for mass production. You'd be better off bending marine ply and build it like a boat, then FG the exterior. I considered that for awhile, but:

You want insulation.
Sandwich structures are stronger and stiffer for the weight, so might as well make the insulation part of the structure.
Rectangular shapes are more space efficient (flat panels).
Wood has a tendency to rot.
Fiberglass is a strong, low density (compared to metal), non rotting or corroding skin material.

So... foam core with fiberglass skins is the way to go. Bonding skins to foam or wet layup. Light, good insulation, fairly cheap, not too hard to work with. Easily repairable if you do wet layup.

If you prefer you could use marine ply for the interior skin (the really thin 2-3mm stuff). Cost is about the same.

 

[J!m]

I already had an aluminum skin and inner structure in my case (back of my 110) but what I did for the interior was to set the foil faced foam (1” thick) between the ribs and then cut (very cheap) textured fiberglass panels often found in dive bar restrooms and the “Notel” off the inner state...

They have nice PVC joint pieces and edge dress up bits too. I fastened it with zinc plated self taping screws with a flange head. Low and cheap by the box...

It has survived many expeditions including the arctic circle (in February) so it was better than the single sheet of aluminum alone.

I have a second rear heater that uses engine coolant and at -20 outside we had to open the windows as it was surpassing 80 inside when we wanted to see “just how warm we can make it in here”... That clearly doesn’t help when the engine is off, or more accurately when you are not driving, as sitting idling the temp gage drops on the 300Tdi.

You guys are building super igloos, but maybe that cheap fiberglass stuff will Work for you.

 

[rruff]

You guys are building super igloos, but maybe that cheap fiberglass stuff will Work for you.

If that's what I'm thinking of, the restroom liner is thick and heavy and not very stiff or strong. There was a guy in SoCal who made single wall truck toppers out of that (with an aluminum frame) many years back. I think he went out of business. There are a lot of things you can do if you aren't too concerned about weight. I think I'd rather use thin plywood as an inner liner. Would save weight and look better, but would cost more and need to be finished.

I'm not going to camp where it gets below freezing very often (else I'll just move). Never had heat. I was thinking about the "boat" construction I described above with no insulation, but did some quick calculations and insulation definitely helps with just body heat and a couple candles. Plus it reduces the effect of the sun beating down on hot days.

 

[J!m]

The 4x8 sheets are on par with 1/4” Luann ply weight-wise I’d say. I didn’t weigh them however.

I was not suggesting a structural use of the material, but it’s white, cleans easily (with a hose if needed) cheap, light (ish) and durable (ish).

The “smooth” side could probably be used with glass or carbon cloth and west system epoxy to make something structural.

 

[Hillbilly Heaven]

Sound like FRP panels used for bath and shower surrounds.

 

[rruff]

The 4x8 sheets are on par with 1/4” Luann ply weight-wise I’d say. I didn’t weigh them however.

The thin .09" ones weigh 20 lbs. 2-3x the density of plywood. $32/ea https://www.homedepot.com/p/4-ft-x-8-ft-White-090-FRP-Wall-Board-MFTF12IXA480009600/100389836

Been a long time since I looked at them. They could be useful for interiors. On the outside you'd need a UV proof coating.