Teardrops n Tiny Travel Trailers

I just posted a greetings in the Introductions sections so here goes the questions. I want to build a very light weight 14 foot canned Ham trailer based on the 14 foot Caravan plans in the Vintage Plans section. I am a guitar builder that appreciates new design developments. Recently I have seen and read about similar designs 2 different applications and now a personal need. That is the lattice braced classical guitar top and in home construction the SIP or Structurally Insulated Panel. After doing some searching it seems that this design can be DIY built and can be Green.
Has these been used before?
Is there a thread?
Thanks, Me

Basically the SIP construction is a composite sandwich. The foam core reacts the shear (theoretically – actually in a house there isn’t much shear in the foam, but it does stabilize the outer skins (or facesheets)). Typically the facesheets are made from OSB (oriented strand board) like is usually found in house construction. That stuff has a lot of funky glues in it, or used to anyway, so I don’t think I would use that exactly (plus it’s not particularly light), but you could certainly make your own SIP using plywood (1/8 or ¼ depending on location and loads).

This can be done several ways when building a teardrop. You can use plywood skins and foam core, or you can use fiberglass skins and foam core, or you could even use plywood core with fiberglass skins (though that might not be so light). It can certainly be done and one of these days if I can ever make it back to the States, I plan on building that way.

I’m building really small, to tow behind a microcar, so I’m leaning toward the foam core and fiberglass facesheets since the loads are really low, but if I were going to build something substantially larger, I would probably use plywood facesheets and foam core. Why, because the plywood is thicker and more stable, so if the loads were bigger I think there is probably an advantage to using the plywood.

I think the key is to close out the panels with a strip of wood that replaces the outside inch or so of the foam core so that you can have something to screw and glue to when you join one panel to the next. If you need to mount something or introduce a concentrated load you can drill a hole and glue in a dowel or plug.

The only tricky part is that if you want to make a curved SIP, it’s not as easy, though I think with some planning it can be done.