C5500 (Kodiak) - Composite Expedition Build is Underway

[Tomadoggy]

I disagree about the quality/strength of Styromax...Have a look at this: StyroMAX DIY Workshop- How strong is the glue? - YouTube Also I am not a fan of the Total composites look/corners and lack of internal routing for utilities and strength reinforcements.

 

[rruff]

Sure it's good glue... but the skin ripped off the foam. The foam is the weak point.

TC does internal routing and reinforcements on request. There is internal routing in the extrusions already.

I'm not saying that the Styromax campers fall apart regularly; I have no idea... but they use the weakest core and least durable edge joining method of any panel builder I've seen. Have you checked into prices to build and ship? There is a panel maker in the US you might wish to find if you're ok with assembling yourself; came up in a thread a few months ago. As I recall they were ~$10/ sq ft for PU foam core which isn't bad.

 

[mog]

I am not a fan of the Total composites look/corners and lack of internal routing for utilities and strength reinforcements.

You might want to look at Globe Trekker (in the Pacific Northwest) as their panels come with extrusion channels/reinforcements in the panels standard. Also, their jointing extrusions are aluminum (that have a very cool molded-in thermal break) so a very different 'look' than TC and very useful tracks (in two axis) as part of the extrusion.
Disclaimer - No relation to Globe Trekker or Total Composite

 

[rruff]

You might want to look at Globe Trekker

I don't know about the product itself (I do like the extrusions), but their marketing is ~50% pure BS.

 

[DiploStrat]

And I have my new custom MRAP wheels from Staz, and have Pirelli's mounted.

Watch the bolts on Stazworks wheels - they can break or loosen and lead to sudden deflation. Those look bigger than those I had and, hopefully, you will not have a problem. But check them religiously until you are sure.

 

[Alloy]

They use a weak styrofoam core, and their edges are just butted together and glued. Have you compared prices to Total Composites?

When it comes down to it the glue, how it is applied and curing process (roller / vacuum / press) has more to do with panel strength. If one wanted a stronger panel then XPS (Styromax) or TC (PU) could use a higher dencity foam but that add weight where you don't want it.

The benefit of XPS is zero water absorption.

Mfg. XPS is under pressure because as environmentally friendly as pouring used oil on the ground.

 

[Alloy]

I disagree about the quality/strength of Styromax...Have a look at this: StyroMAX DIY Workshop- How strong is the glue? - YouTube Also I am not a fan of the Total composites look/corners and lack of internal routing for utilities and strength reinforcements.

My $0.0002 would be to run the wires on the surface as much as possible. Three reasons:
1.) It can be secured......conduit works in buildings where there is very little vibration.
2.) If the wiring isn't pulled all at once there is a good chance the friction from new wires on the existing wires will cut the insulation. PVC insulation on low votage wire is soft.
3.) Conduit fills up restricting future changes/upgrades.

 

[Alloy]

I don't know about the product itself (I do like the extrusions), but their marketing is ~50% pure BS.

Those extrusion are overkill and add weight that isn't needed.....especially if the mouting frame is done properly.

 

[DiploStrat]

My $0.0002 would be to run the wires on the surface as much as possible. Three reasons:
1.) It can be secured......conduit works in buildings where there is very little vibration.
2.) If the wiring isn't pulled all at once there is a good chance the friction from new wires on the existing wires will cut the insulation. PVC insulation on low votage wire is soft.
3.) Conduit fills up restricting future changes/upgrades.

From painful experience, I would add another reason - WHEN, not if, when some of the wiring fails or has to be modified, you want it to be accessible. But if you must run everything in conduit, remember to leave a spare fish line in with the wiring.

 

[rruff]

When it comes down to it the glue, how it is applied and curing process (roller / vacuum / press) has more to do with panel strength. If one wanted a stronger panel then XPS (Styromax) or TC (PU) could use a higher dencity foam but that add weight where you don't want it.

I don't know what TC's PU density is, but I made a bunch of samples using 25psi XPS (~1.7 lb/cu ft) and 4 lb/cu ft PVC (which is ~150psi), and the difference was huge. PVC and PU don't absorb water either. PVC is commonly used as a core on boats.

The core is a fine place to add a little weight IMO, for strength and impact resistance.

From painful experience, I would add another reason - WHEN, not if, when some of the wiring fails or has to be modified, you want it to be accessible. But if you must run everything in conduit, remember to leave a spare fish line in with the wiring.

No wiring in my walls. If I built a house I wouldn't put it in the walls either... nor pipes or anything.

 

[Alloy]

I don't know what TC's PU density is, but I made a bunch of samples using 25psi XPS (~1.7 lb/cu ft) and 4 lb/cu ft PVC (which is ~150psi), and the difference was huge. PVC and PU don't absorb water either. PVC is commonly used as a core on boats.

The core is a fine place to add a little weight IMO, for strength and impact resistance.



No wiring in my walls. If I built a house I wouldn't put it in the walls either... nor pipes or anything.

1.7lb vs. 4lb (double the weight) I'd hope there'd be a huge difference.

Don't know about PVC but PU does absorb water.....why it can cause issues if not installed in a building correctly.

 

[rruff]

For 2.3x the weight the PVC is 6x the strength. The skins and core on mine each weigh ~.5 lbs, so using XPS instead of PVC would have saved about .3 lbs/sq ft, or little over 100 lbs total. But it would be a lot weaker. I actually wouldn't use it without core reinforcement which would make it heavier than PVC.

The PU foam I looked at for panels has <1.5% moisture absorption by weight.

 

[Tomadoggy]

I have read countless threads about the pros and cons of various composite walls and construction methods. Suffice it to say that I am undecided and plan on finishing the design first, then determining the one that is right for me. I have owned 11 different campers and certainly understand the ins and outs of repairing all systems. However since I am building this myself don't have a worry about failed connections/wiring as I am a meticulous builder and can assure you that every connection will be made robustly and every single wire properly routed/supported to avoid rubbing etc. Weight is not going to be top of mind as this rig will already be very large and heavy. Structural integrity will be paramount!

 

[Tomadoggy]

Watch the bolts on Stazworks wheels - they can break or loosen and lead to sudden deflation. Those look bigger than those I had and, hopefully, you will not have a problem. But check them religiously until you are sure.

I have also seen the old videos/articles about some of his earliest wheels and the bolt failures. The ones I have are an entirely different design which simply uses a newly machined inner plate that uses the stock MRAP bolts to the rim. When mounting I did check all of these bolts and they were very tight...however message heard, I will certainly keep an eye on them.

 

[rruff]

Weight is not going to be top of mind as this rig will already be very large and heavy. Structural integrity will be paramount!

Pretty sure you are going to want a pivoting subframe. Have you thought about that at all?