XPS Sandwich Panels availability in the US

Alloy

Well-known member
Polyurethane is fine and can sometimes actually have a higher R-Value than XPS but in my case I am specifically planning to use the XPS for my floors and I am milling out the XPS to insert PEX for hydronic heated floors. Since apparently there are no US manufactures of XPS or Fiberglass Sandwich Panels, my plan is use Foamular 600 and apply my own reflective foil. Foamular 600 has a compressive strength of 60 PSI and an R-Value of 5/inch. For the walls of my van I am using Closed Cell Spray Foam (PU) for an R-Value of 6/inch.


Checked the thermal drift of XPS, PU and EPS in 2-5 years.

Wouldn't be my choice to cut into the floor for the hydronic lines. There's pile of retrofit hydronic system to lay on the floor.

Spray foam is good but if it gets near moisture it absorbs (max. 95% close cell) water. The industry thought open cell would let water run through it but open cell is a worse sponge than close cell. It's the worst insualtion for retrofits.
 

Alloy

Well-known member
Even the 25 psi foam has been known to hold up in panels for a long time. But PVC is stronger by spec (4lb is ~150 psi) and easier to bond. It's ubiquitous in boats, while XPS isn't used.

StyroMax in Australia uses XPS.
 

ripperj

Explorer
Likely because they actually work on their vehicles and fab up a lot of their own stuff versus US folks buy stuff they can bolt on.

This…. Holy smokes, very few people over here have any hands-on skills anymore.

Like the stupid cartoon says” 50 years ago a car manual gave you specs on valve lash adjustment, now the manual cautions you not to drink the contents of the battery”


Sent from my iPhone using Tapatalk Pro
 

Tiktaalik

Supporting Sponsor
They are very responsive. I have a call with them next week.

No problem. I think they're the supplier for Bison Overland's truck campers. I have a few other manufacturers bookmarked but I think Martel is the only domestic manufacturer in my list using XPS.
 

Tiktaalik

Supporting Sponsor
I will ask them about their CC 4lbs PVC. I’m not set on XPS, just looking for a FRP sandwich material with a high R value, that is rigid and that will bond well.

Check out PVC foam from Carbon Core... or just get Divinycell if cost isn't an issue. Standard XPS is not very strong (even 60 psi) and it's hard to get a good bond. I used the CC 4lb PVC and have been very happy with it.
 

rruff

Explorer
I will ask them about their CC 4lbs PVC. I’m not set on XPS, just looking for a FRP sandwich material with a high R value, that is rigid and that will bond well.

R value is as good as XPS, and it's stronger and bonds better. It's heavier also, but...

For bonding, an issue with XPS is that the cells are extremely tiny. PVC has much larger cells so that when you cut it you have a micro-rough surface that latches onto epoxy better and creates a stronger interfacing layer.

Note on CC, whenever I bought foam from them there was sort of a flat rate of ~$350 until you hit I think $3k in one order... then freight was free.
 

Victorian

Approved Vendor : Total Composites
Total Composites was downright rude when I asked to purchase a few panels.

I’m not set on XPS actually but I do want the highest R-value possible in a FRP format.


Seriously? You just didn’t accept my answer that we don’t just sell panels. Kept asking…… At that point we sold camper kits, not just the panels or pultrusions .
 
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Louisd75

Adventurer
Total Composites was downright rude when I asked to purchase a few panels.

I’m not set on XPS actually but I do want the highest R-value possible in a FRP format.

I didn't have that experience, but it was a bit frustrating that I couldn't use them as a source for panels since I'm just a short drive and ferry ride away. I think in my case it was the experimental nature of my build and, in all likelihood, Andreas' experience has probably been that experimental projects like mine can turn into a huge time suck on his end. Kind of moot now as it seems like they've moved to a dealer model, similar to how Tern Overland has. Regardless, I wouldn't say it was a bad experience and I've sent links to his campers for friends looking at something along those lines.

Right now I'm looking at going with PVC via Fiber-Tech (which would be a bit of a drive) or rolling my own with Divinycell cores (I have a local source for those, but that's a lot of work). I still need to finalize my design a bit more and tweak it to what I want.
 

Peter_n_Margaret

Adventurer
I am currently building my second fibreglass sandwich panel vehicle in Oz.
The first is now 18 years on the road.
The second will also feature closed cell polyurethane foam and a frameless construction (except for the floor which will be closed cell PET foam for better crush strength).
XPS simply does not have the structural integrity, in my view.
Cheers,
Peter
OKA196 motorhome
 

DzlToy

Explorer
I always find it suspicious when a manufacturer doesn’t specify what “foam” they use in their products. That’s a deal breaker. XPS or bust.

EPS and Polyurethane CAN work, as long as the box is properly reinforced, so the load is taken off the core material of the sandwich. If you REALLY want a structural sandwich panel, you will need to use something like Gurit or Divinycell and a carbon, fiberglasss or Aramid skin, impregnated with epoxy or vinylester resin.

I built a 12' x 7' x 7' box with a friend using thin phenolic sheeting, 2" EPS, wood nailing/screwing blocks and 16 gauge steel angle iron as a perimeter frame. That box was RIGIDLY mounted to an LMTV and the truck was driven from Alaska to Baja without any issues.

Four point mounting systems, vacuum infusion and $50,000 of Nomex honeycomb are not required. You can build a box or a trailer with Vetroresina or G9, angle iron, industrial spray glue and XPS sheeting from the DIY store. Overlap foam and sheeting to make larger panels, using 4x8 or 2x8 sheets.

DO NOT use polyisocyanurate foam unless you have an external and/or internal support structure. The foam is a crumbly mess.

Commercial refrigeration panels are also an option and are often constructed using stainless or aluminum. Exterior and interior can be sprayed with aliphatic polyurea to seal everything up.
 

simple

Adventurer
Since I've been following TC, they haven't sold parts individually. They sold custom DIY habitat box kits and have now added the slide in campers.
 

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