Ahh,
@rruff the foam man himself
Foam first: That's disappointing to hear about the XPS. I will try my luck with the Foamular 250 sometime this week using 60 grit scuffing like Terra Ops did and the Soller 820 epoxy. I'm really hoping I can make it work because the price difference is a big deal to me. My FRP seems to have a light fabric on the back so I wonder if that will help adhesion (
http://www.uslco.com/download/VRTech_W.pdf, mine is VR2). The line in that about poured foam systems makes me wonder if that technique is DIYable. Maybe do a pour foam and plane it to height with a hotwire? Or constrain the thickness to 2in (so you can bond to both panels on one pour) and let it all overflow out the sides to be trimmed later... I wonder what the compressive strength of poured foam is. Also cost, always cost.
R6 per inch would be plenty on the foam you have listed. Also 40 psi vs ~150 psi wow. That's certainly a world of difference. What does your wet layup look like? Carbon twill? I wonder if there is some way to help reinforce the XPS 250. Maybe the plug method like Terra Ops has talked about but my gut says it wont help more than an inch or so around the actual plug, leaving other sections of the panel to fail. IDK I'm no material scientist though. 3D printed homemade honeycombs anybody???
Also, I believe TC uses PU foam for their panels "High gloss FRP/PU foam core/high gloss FRP on sidewalls, front wall, and rear wall" from
https://totalcomposites.com/expedition-trucks-rvs/ .
Everlanders and you (rruff) have both stated adhesion issues with foam. Everlanders provided no details as to foams tested etc. Whereas Terra Ops and Sawtooth Unlimited have both had success with XPS (Terra Ops 40 psi DOW and Sawtooth 30 PSI DOW (probably actually 25psi)). Admittedly Sawtooth had some localized adhesion issues with his vacuum table setup but he is still moving forward with the build. We will see where I come out on all of this. Any idea if DOW vs Owens Corning (Foamular) matters?
?♂️
Subframe: Everlanders shows a picture or two of it in this video (
) before 9 min is all history (interesting but not relevant to this). They also talk about their kinematic mounting system which I will be doing my best to copy
. These are two more videos that show the subframe
and
. TC seems to have FRP U beams built into their floors which serve as the structural rails.
I have an 165" WB 2000 F-450 so I think I got a case of the flexes. F-450 is identical to the F-550 (in the 1999-200x era) besides rear axle. I think the Everlanders show how much flex the were able to get with a jack in that "most asked questions video" and it was like 4-5" so I'll be in the same boat.
I'm drawing most of my subframe/truck/layout inspiration from the Everlanders and my panel construction inspiration from Terra Ops. I plan to start documenting it on video starting with panel testing. I figure people can learn about the specifics of their truck from whoever but the subframe, panel construction, and box construction is what is so hard to find/daunting. Honestly I thought it was out of my league until I saw Terra Ops' awesome thread.
Probably a really rambling post. I have been researching this stuff for months with only my poor girlfriend and close friends to listen to me haha. Happy to talk with some other people who have done it/are doing it.
@Terra Ops "Being in and experiencing the grandness of nature puts life in perspective. Something that I think the whole world could use." I couldn't agree more! Also, glad to hear you would go back to a cab-over bed because that's my plan. It sounds like you're at a good spot weight wise on your truck. I'm honestly confused as to how the Everlanders got up to 14k lbs but I guess you carry a bunch of stuff when you go out for months.
-Derek
Ehh looks like my youtube links ruin the formatting. Ohh well, y'all will live