What does "Light Weight" mean?/

[IdaSHO]

Thanks,

So what thickness is typical for the polyurea coating?

 

[The Artisan]

LineX is usually .62mill around 1/16". Guess my point is, if I can build a camper of this size there should be no issues making a small truck camper empty for 4-500lbs.
Kevin

 

[IdaSHO]

What panels are you using exactly?

I find it very hard to believe that your FRP composite panel is just 1lb per square foot, knowing that traditional 1/16" FRP alone is .61 lbs per square foot.

 

[downhill]

My build is light for the size 12.4 x 7.4 x 7. 2" FRP composite panels, 14 gauge 4x4" roadcage, add 1/8" polyurea coating, light trays,door, windows and flooring is around 1200 lbs . Water tanks will be on the truck.
Kevin

2" FRP composite? or is that 7.2? From the weight you gave I'm assuming you are using 1" FRP right?

 

[The Artisan]

Foam and skins are 2 1/16" total thickness. I looked at .030 alum sheet, its just a tad heavier.
Kevin

 

[The Artisan]

Kenny the skins are heat pressed glued thin fabrics .040 thickness, tensile strength around 25kpsi
I will divulge more info later as I will be the supplier for the co for those that want to do a DIY build.
Kevin

 

[downhill]

They have a neat product for sure, but it certainly isn't a one-size-fits-all, and personally I feel it is still on the heavy size.

My prototype I use as my own camper came in at roughly 700 lbs (shell) and it is considerably bigger.


But again, we are getting back to my point that regardless of construction, the shell weights are actually pretty similar.

Composite core, XPS core, stick framed, aluminum framed... none of them are substantially lighter than the other once done up as an insulated shell. So it begs the questions....

So where do you expect to save weight??

I will use either 3/4" or 1" FRP, minimal windows, and I'm playing with different joint designs. Basically, you make things lighter by defining what the true engineering requirements are and choosing the materials and methods to match those criteria. It has to be a comprehensive approach. I'm not expecting to use the same things in basically the same way, and get a new result. There will be no cold bridges in my design. Extensive use of high strength adhesives. I'm looking at using some aluminum, but none will penetrate the wall barrier.

 

[IdaSHO]

Interesting. And you said EPS foam?

Ill be watching for you to divulge your source.

Sounds like a decent panel for the DIY.

How does the strength compare to XPS core?

 

[IdaSHO]

Basically, you make things lighter by defining what the true engineering requirements are and choosing the materials and methods to match those criteria.

Thats what Im getting at.

At the end of the day, you still have a fixed square footage of wall, ceiling, floor, and partitions to account for. No amount of defining requirements or selection of methods will change that.

Once you get to a certain point (I feel we are already close) no matter how you plan, there is no magic bullet to shed weight.


The magic bullet will be in the form of a new material IMO. Nothing that is being used today is light enough to make a substantial difference.

And even then, I fear it wont be cheap enough to be a viable option.


To be viable it must be:

Rigid
Light
easy (enough) to manipulate
priced right


Tall orders........ :coffeedrink:

 

[The Artisan]

Kenny its the overall build of the SIP that creates the strength skin/glue/foam/glue/skin. I know my buddy Dzltoy likes XPS better, never compared them. This is my first proto so this is the foam I chose due to availability and cost, my foam is 2.5lb density
My overall goal is to sell the box and fuso. Do a ujor build with a popup hardside. Or a NPR and send it to RC for 4x4
You might have seen my design I have a folding bed. In the popup release the latches and the torsion spring lifts my bed frame, it locks in place and holds the top up.
No struts or actuators that fail over time.
Kevin

 

[rruff]

Interesting. And you said EPS foam?
How does the strength compare to XPS core?

Here is some info on EPS and XPS: http://www.foamular.com/assets/0/144/172/174/98cf58e1-c3d2-4b6c-beb5-2063215bea18.pdf

I've spent a lot of time researching, and I just don't trust the structural integrity of the polystyrene core or the bond with a fiberglass skin. If either fails, then your camper may not be fixable.

That's why I'm going with panels that have wood around the edges and light wood stringers, similar to your design. And plywood skins, not just fiberglass. Thin plywood with a layer of fiberglass is more weight efficient than just fiberglass for equal puncture and dent protection. And the wood frame and stringers give you an easy way to attach panels and mount things.

 

[redthies]

I just recently took delivery of my factory ordered a 2017 Northern Lite 9-6Q. It is a full basement non-slide fibreglass constructed camper. I went out of my way to get the least amount of added weight possible and it still came in at 2600 lbs. This is obviously not in the same league as the ultra light composite panel custom campers you guys are talking about, but I needed something readily available and financeable. I spend 150-200 nights per year in my camper (for work), so it is a 100% tax write off for me. Given the amount of time I spend in it, it needs to have all the amenities of home. The reason I bought the Northern "Lite" is the quality and construction. There is not a single piece of particle board in it. Everything is birch ply or solid hardwood. They have saved weight where possible (Seitz acrylic dual pane windows etc), but it still uses conventional a Dometic and Attwood appliances etc. I'd love to know what the "shell" weight is on my camper with just the interior fabric, windows, vents and door installed. I bet it's around 900 - 1000 lbs max.

The reality is that the weight game is a hard one to quantify as everybody has a different end goal, and shell weights are really the only apples to apples compareable. Once you start adding amenities, there are so many variables it's mind boggling. The best thing is to figure out what your needs are, and then get the lightest thing you can afford to fill that roll.


Edit: I got to thinking about "Jeep" and his composite camper build ( http://www.expeditionportal.com/for...nd-composite-panel-build-on-Dodge-2500/page62 ) and wondered where he got to with weight... Post #612 has it at 2600 lbs dry. Makes me feel a whole lot better about my new camper!! The attention to detail and quality of components in his camper is mind blowing, yet we end up at the same dry weight. I'm calling that a win.

 

[UHAULER]

Found this company. Maybe they can make what you want http://compositeapproach.com/project/madcap-adventure-campers/

 

[gmacmt]

Light, durable, cheap. Pick two.

 

[downhill]

Found this company. Maybe they can make what you want http://compositeapproach.com/project/madcap-adventure-campers/

That's a nice shell! No prices though.