Gator417 wrote:I think some people are confused at my question. Plywood is the heaviest material one could possibly use in a camper. I'm asking why use it if it is so heavy and prone to rotting and delaminating.
Okay... 1/16 sheet steel 8x4 80lb, 1" 1/16 plywood 8x4 80lb, that's some pretty thick plywood to weigh the same as some not very thick steel.
Also if you're thinking "lightweight steel studs" ... they're only lightweight if they're for indoor non-structural framing, basically to gap drywall off something solid. Structural steel studs basically same weight as a 2x4.
It's prone to rot and delamination if you don't protect it, but everything else also has issues is you don't use it right. Plastics have UV problems, steel can have rust issues, and terrible condensation issues, brings the cold right in, as would aluminum structure... gets complicated to insulate. You are aware that's there's 50+ year old vintage Plywood Cruisers around that have been on actual water their whole lives, protecting it can be done effectively.
I've seen plywood used extensively on RC aircraft, it was dependent on special 1/32 and 1/64 hobbyist plywood though. 1/32 for the fuselage, 1/64 for the wing skin. Piece of common or garden 1/8 for the firewall. Was more popular in Eastern Europe during the time they couldn't get any balsa though. They'd be making wing ribs out of orange crates and cutting holes in them to lose a bit more weight.
Sure there's tonnes of things you could theoretically make it from, but lacking things like an inert atmosphere for welding, a curing oven for high tech composites, etc etc, plywood is the one that works in teh average garage.
Let me tell you about modern composites, they have most of the resin sucked out of them by vacuum, then are oven cured. if you don't have the means to do that, you end up with heavyweight sh** that was just nasty and smelly to make. Rutan makes some foam core fullsize planes, but it ain't a particularly popular homebuild aircraft method.
Now foamie and PMF looks promising, but there's still issues to solve for scaling it up much, hard points can be an issue, and even price of the stuff can be ridiculous in small quantity.
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