Composite Panel Musings

hidn45

Member
How many of us have gotten the canned spray foam somewhere it shouldn't have been & had it cure there? Tenacious stuff isn't it? The thought has occurred to me to take advantage of that property to make composite panels. In fact, we built our house from Structural Insulating Panels made just that way, except that the skins are OSB. The bottom skin is laid in a form, liquid polyurethane foam is metered out of a spray bar onto the OSB, the top skin follows the spray bar, & then a top frame is locked down over that to contain the pressure of the expanding foam. No adhesives - the foam self-adheres to the skins. Pretty simple process. This particular facility is set up to make panels up to 8' x 24'.

Aside from some trial & error to get the volume metered correctly for the intended panel thickness, can anyone think of a reason this technology could not be used to form FRP-skinned composite panels? One thought is whether the waterproof nature of the FRP would inhibit the foam cure, whereas the permeability of the OSB allows gasses to escape? I'm planning some small-scale testing once it warms up here (from the 4 degrees F we have this morning), but larger panel sizes may manifest issues that do not occur in a small sample piece.

The foam distribution technology could be borrowed from the spray foam industry, with multiple spray heads off a manifold bar on tracks replacing the single hand-held nozzle the guy uses in your attic. The form would be a simple aluminum or steel framework. Engineering calcs would provide sizing for the form framework to contain the pressure of the expanding foam.

Maybe this falls in that black hole where it's too much for the backyard, DIY guy to take on as a proof-of-concept, but not enough potential return for commercial technology to invest in the necessary startup development? Any thoughts?
 

ITTOG

Well-known member
Here is a similar concept that was recently built. May give you some additional thoughts.
 

highwest

Well-known member
Here is a similar concept that was recently built. May give you some additional thoughts.
Video w/ pour foam panels: @Traveling 2gether Journal
 

hidn45

Member
Thanks, ITTOG/ highwest. Yes, I watched his videos, hadn't realized he had a build thread on here. Couple extra steps, but, yeah, that's the sort of thing I'm thinking of....
 
Maybe this falls in that black hole where it's too much for the backyard, DIY guy to take on as a proof-of-concept, but not enough potential return for commercial technology to invest in the necessary startup development? Any thoughts?
You're correct. At least for me as a DIY guy, I don't have an indoor space big enough to operate an apparatus like what you are talking about, let alone the capital to invest in building and testing such a thing. If you are planning on producing campers commercially, then maybe it would workout, but for one camper it would probably be cheaper to get commercially produced composite panels.
 

hidn45

Member
Hey Matt - thanks for checking in! Yeah, I had a feeling this would be another one of my hare-brained schemes with nowhere to go, but hey, sometimes you just have to run it up the flagpole & see who salutes, eh? There's a friend of mine here in town who does spray foam, & if my small sample testing shows good results I may just build a containment frame & have one of his guys shoot a full size FRP-skin panel sometime when they're doing a calibration spray. Just for fun....

So, overall, what are your thoughts on your pour-foam panels? Any issues, like delamination, foam degradation from road vibration, etc.? Did you get the thermal performance you were expecting?

Looking forward to seeing your new camper out in the wild!

Thanks again-
Randy
 

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