Teardrops n Tiny Travel Trailers

Westley wrote:Yes, it's my understanding that the "P" stands for plastic.

But it's also my understanding that they include polyester resin in the definition of plastic.

So, I thought that in the mfg process, the FRP is made using fiberglass and polyester resin.

I do know that if sanded in prep, FRP and epoxy will stick together super well and bond with cured laminated fiberglass like used in boat making, which I think is cured polyester resin and fiberglass.

I haven't tried bonding FRP with XPS, yet, but I did bond 1708 fiberglass with XPS using epoxy resin. The result seems very strong for just one laminate.

I have a supply of FRP that I scrounged. It's the type used on the roof of the over-the-road trailers. I've used a little of it and find it to be very strong and bonds well. It's quite flexible and about 1/8" thick or less.

I used two of the XPS 150 sheets from Home Depot for the experiment, each 2'x2' X 1" thick. I roughed up the surfaces with a RO sander, 40 grit. The fiberglass/epoxy is in the middle of the sheets of XPS. When cured, I trimmed and squared the edges on my table saw.

With the resulting 2" thick panel is suspended by the edges, laying flat, I can stand on it, bounce, and it holds my 220 lbs just fine.

I don't know if that's a sufficient test or not. There may be other issues with 150 XPS, such as heat and perhaps delamination from stress, or perhaps expansion/contraction from temp changes, leading to delamination. The XPS is not strong stuff, and if there is failure it will be the XPS that gives way, not the epoxy/fiberglass.

So, I thought that in the mfg process, the FRP is made using fiberglass and polyester resin.