Found a Dynamo TCX to finish, looking for input

[Dynamo TCX]

Hi all,

I came across one of the partially built Dynamo TCX full size truck camper frames for a price that I couldn't resist. It's the 8 foot long model and is all 2x2x0.125 wall aluminum channel that is buck riveted together. Is came with some of the exterior metal panels that are clecoed (temporary rivets) in place and some loose interior panels cut from 3mm ACM (Aluminum Composite Panels). It needs a lot of work but my plan was to build my own from scratch so this gets some of the expense and fabrication out of the way. From the looks of it, they did a nicer job than I would have done anyway.

As you can see from the photos, there is no triangulation in the structure, so the skin will be integral to the design. I'm curious as to what & how you folks would recommend skinning it? The obvious choice is aluminum sheet as that's what's specified on their Facebook page, more specifically: "Kaiser Alclad 20024 T3 Aircraft Aluminum". However they didn't specify a thickness although I'm guessing it's around 18 gauge which is 0.040" thick. Although maybe it's thicker on the sides to handle the significant cantilevered sleeping area?

My next question is; how should I attach the skin? It looks like the manufacturer's plan was to rivet it on but I'm interested in whether any VHB tape or Sikaflex (with micro-balloons to maintain the optimal gap) should be used in addition to the rivets. And I assume aluminum 'closed-end' rivets should be used so it's watertight? I'll likely insulate it with 2" foamboard insulation and then figure out what to skin the interior with which likely will be a combination of ACM panels and maybe cedar boards. I know the manufacturer was insistent on not having any wood in the camper and I'm certainly not going to have any structural wood but I'm not against using some wood for interior items. This camper will be used for year-round weekend trips in the North East, so I plan on putting a heater in it but would like to keep the water and electrical system very basic, at least for now. I don't even have a truck to put it in yet, so my plan is to build it, weigh it, then buy the appropriate truck. Probably will be a used 3/4 ton or 1 ton GMC crew cab.

Anyway, I'm interested in how you folks would proceed, so thanks in advance for any input.

-Gabe

 

[dstefan]

Well, I’m no builder, welder, fabber, engineer, etc. but that said . . .

Ovrlnd campers are built similarly. They use a 1/16 (.0625”) skin that is VHB’d to the welded 1/8” tube 2 x 1” with 1 x 1” for the poptop roof) and riveted using blind rivets.

Sheet joins in the roof are overlapped and sealed with butyl tape and then external sealing, which is cosmetic.

It’s very rigid and stout. No movement, cracking, leaks, etc after 5 years and a lot of off road use.

It looks to me like your cabover could use some , gusseting, triangulation or reinforcement at the moment joint with the front vertical support?

Here’s how Ovrlnd did it on mine. Hope this helps. Good luck with the build — looks like fun!

 

[rruff]

"Kaiser Alclad 20024 T3 Aircraft Aluminum"

I don't think that is a good choice for a camper, as it corrodes readily if it gets scratched. One of the more corrosion resistant alloys would be ok. ACM might be best for this. Or maybe good FRP sheets? Some people have bought from this outfit: https://www.vetroresinallc.com/product-category/g-force-j-force/

My next question is; how should I attach the skin?

Adhesive would be best I think.

I'll likely insulate it with 2" foamboard insulation and then figure out what to skin the interior with which likely will be a combination of ACM panels and maybe cedar boards.

I'd definitely have a continuous layer of insulation; you don't want bridging through the frame, because aluminum's thermal conductivity is very high. 1" of XPS would be enough, bonded to the inside of the frame, not in the cavities.

I'd reinforce where the lower part of the berth meets the vertical front wall, but that should be plenty. That section is really a fat boxed beam and the cantilever isn't much.

Cool project!