Prototype Interior Wall
Details
Interior dividing walls in an airstream — between the kitchen and bedroom, or bedroom and bathroom — are not structural. Their function is just to separate one area from another and provide privacy. They also offer a space within which to route plumbing and wiring, and should play a considered role in managing the acoustics of the space.
Look at most airstream restorations, however, and you'll see the sort of wooden framing you'd normally find in a house, and walls made of thick plywood. Here's one of many examples you can find online.
This doesn't make any sense whatsoever, except perhaps on the grounds of cost and familiarity with the materials. Wally Byam, the founder of Airstream had a mantra: "Ounces make pounds." He was obsessed with weight reduction for obvious reasons: you had to tow the bloody thing, and the heavier it is, the harder and more expensive that becomes.
With this in mind I decided to experiment with polypropylene honeycomb sandwich, a material that is typically used to make lightweight flightcases. The material can be cut very easily with a track saw, then bonded using aluminium L-channels and 3M's double-sided UHB tape.
My first attempt failed. The bond didn't hold which I traced to two problems: first, needing to scuff the panel to provide a better surface for adhesion, and second switching to the "low surface energy" version of the tape.
But the second attempt has worked perfectly. It is phenomenally strong, it provides a clean, flat surface for decoration, with sound deadening material it "feels" like a solid wall if you tap it, and it's light enough that my seven year old son could carry it around with no difficulty.
To finish the prototype I cut a hidden recess for the systems monitoring screen (hidden behind a picture frame) and 3d printed some custom mounts for door hinges to test how those might work.
The result is a vast improvement on how these things are normally done, and if anything, it's actually an easier material to work with than wood.
