Source Possibilty: Extrusion Connectors For DIY Sandwich Panel Makers


New member
Okay, I'm starting a new thread on this topic after endless searches for a source for the DIY'er, to locate EXTRUSION Connectors to attach to homemade composite foam and frp skinned panels to make for a more professional home build with better strength and aesthetics. There really isn't anything out there for the guy that wants to enjoy the journey of building for himself.

I have a Proposal that I would like to invite all of you to give input as to a possible solution for this...

So, what if one were to pick a store bought panel, say Foamular 250, some common FRP smooth glossy roll for skins to epoxy and make a sandwich panel in their garage; Just some common, easy to acquire materials for the DIY'er.... Seems all he would need is a source for the EXTRUSION CONNECTORS to make him complete on his quest to fulfill his endeavor....
(windows and doors? no problem....interior, plumbing, and sweat.
It's the EXTRUSION Obstacle that is keeping me from beginning, as I DO NOT WANT TO JUST GLUE UP TO SOME ALUMINUM ANGLE AND CALL IT GOOD.)

What if someone could generate enough interest on a common sandwich panel thickness, and gather this interest to an extrusion manufacturer, and form a "group buy" scenario for the first order, and then start a business selling extrusion in the U.S. strictly for the Do-It-Yourself people; thus,
Solving The Last Obstacle for DIY Camper Box Builders to attain the professional result they desire?

Thoughts and Input, Please.....

I am currently working with an Extrusion Manufacturer on this very scenario, and drop shipping may also be a possibility.
WHAT I NEED IS INPUT FROM ALL OF YOU, to come up with the Sandwich Panel Core of choice, along with the FRP Skin of choice, to arrive at the Panel Thickness for Extrusion To Be Manufactured. The Best Scenario for materials, would be for the DIY'er to get his foam core and FRP roll LOCALLY to him or her. This would save on the immense shipping costs that skyrockets the build costs. Then he or she could order this extrusion we have developed,
and then Their Beautifully Constructed, Professional Looking Composite RV Camper is built all by themselves
and ready for all the other appointments to finish their Dream to Reality.

'Power To The People!'
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Just do 1", 1 1/2", 2" etc

No way you'll get agreement on materials selection.

I want iso foam skinned with canvas for example.


New member
Would you have any links to these extrusions?
All the ones I see have straight edge corners. I'm looking for a rounded corner and end cap.
The problem with just making extrusions in 1-1/2"-2", etc. is the locally found XPS foam is already at those nominal measurements...
Now add a 2-5mm skin to each side to make a composite sandwich panel, and the extrusion will not fit.

(not a legitimate 'Expo-Guy)
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New member
Just examples. Make them in whatever increments you think best, the market will give its feedback.
That is just pissin' in the wind....
I'm not about to guess and spend money, trial-by-fire style and have "the market" feedback negative and waste that cost.
You'll have to do better than knee-jerk responses as the beat-all answer. THAT is what this inquiry is all about:
Arriving at a feasible solution to making DIY Composite Sandwich Panels, using locally to everyone in the USA, XPS Foam and FRP Rolls for Skins
that are the most common, affordable, easy to attain for everyone. Then once a conclusion is made as to the best all around Foam Panels and Rolls that the majority can agree on,
we measure the thickness of the completed chosen composite panel, and I send those specs to the manufacturer of the extrusion.
I could just go and build this for me using what I find to suit my needs and be done with it. I would much rather have Feedback from Real People that have Actually Made Their Own Composite Panels using what they have found locally to them. Thought maybe I could help people with a much better way to build their campers as well by coming together.
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As I said you won't find many at any one time, nor will you get agreement in advance.

I would however, modify my panel design to match your extrusions & fittings if they were readily available.

Start with just one size then, see how you go.

Or meantime, anyone know where to buy, please post.


Start with the most budget minded approach. Most people don't need super thick walls so do 1" plus whatever thickness FRP is cheapest and most common. If I ever build another box, I want to take this approach.


Viking with a Hammer
If you decide to use 1" thin walls, you then have 1" of room to frame said walls where the meet the extrusions. Which thin walls might need anyways.

These guys already are doing what you're asking:

Just ask for a group buy. Pretty sure they used to advertise here.
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New member
This is the sort of input I'm looking for....
So now we know that Foamular 250 wont do the job.
So what's out there as far as a 2" thick 4 lb. density foam panel that is readily available to most everyone
to get locally to them?

And I conversed with Total Composites, and the said they will not sell their extrusion alone.


The TNTTT "Foamie" community uses lower-density insulation panels, tensile strength reinforced with cotton / canvas, glued with Glidden Gripper.

aka PMF, poor man's fiberglass.

I realize not what you're doing, but many there would very much also be in the market for the extrusions you're talking about.

There are also some higher-tech composite panel DIYers that hang out in other TNTTT subs.


New member
Now we are starting to get somewhere.
So you trust the Dow 60 with good skins? are you using FRP?
I'm not very familiar with using phenolic.
if so what brand? This feedback on what foam and skin is what I'm looking for.
Ideally, the foam and skin should be affordable and easily attainable by all here in the USA.
Finding the right combination will determine the wall thickness down to the millimeter.
THEN, extrusion would be ordered to fit the combination.

Also, when I make reference to FRP, it could mean Filon, or some other glossy sooth UV rated skin.

/QUOTE="The Artisan, post: 2660718, member: 112600"]
That will be the hard part. Not many local distributors have structural foam let alone construction grade foam, Divinycell is about $900 for a 4x8 sheet.
I am in Atlanta and only 1 place sells Dow 60 xps that is around 2.6lb. I am fine with that as my phenolic skins are compressive 40k psi and structural 37k psi, then I have .118mill polyurea coating on each side. Maybe do a group buy on extrusions, then your group can decide.
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Do you really need this type of extrusion? The Europeans have been building and using composite panels in expedition vehicles since the 1980s. I only know one builder (Bimobil) who uses extrusions like the ones you are looking for. Everyone else just glues the panels together and simply covers the corners with a simple corner extrusion. Easy and it works regardless of the thickness of the panel.


New member
I don't think this idea is all that crazy.
For me, I like Form. I do not want to have sharp edge corners of steel or aluminum.
I want nice rounded edges and corner caps. I want really great results and a beautifully made camper.
I am looking to find a source for "Reefer" truck extrusions sold in the USA.
I just haven't found any as of yet. This has led me to think, why not just get some extrusions made
for a common Foam and FRP combo that anyone can get locally?
Get the foam, epoxy on the skins, join all the panels with some nice extrusion, enjoy the process.
It makes more sense to design the extrusion for a combo that is affordable and easily attainable, so that when I make a production run,
it will work for everyone and sell.
That's my goal.


New member
Foamular 250 was just a mentioned example. I am still unsure of what XPS to use and where to get it.
This also rings the same for the Rolls of FRP/Filon or other product. This is what I would like feedback on.
What are the majority of builders using? Hopefully it is a good balance of strength, availability, and affordability.
This is what I seek. I've read about the high test XPS, which is expensive, and maybe that it isn't required. I've read about
builders using Dow 60, which seems to be a good balance, but again I have no experience with it.
Again Kevin, the answer is No to your suggestion you have mentioned a third time now. I will not just jump into an investment
blindly. That is why I am here asking questions.

Maybe I need to start a thread by asking a different question....
- Consensus Question -
What brands and types of XPS, and FRP are DIY builders using most often when constructing their own composite sandwich panels?
What have you read? What do you know? How is it all holding up?