Steel vs Aluminum tubing (Camper frame)

[montaillou]

interlocking aluminum slats

Not sure this is for me. I don't want to say I'm building on the cheap, because in some areas I'm spending a lot, but in some areas I don't want to spend too much either. After all, this is all going on a Deuce, not a Ford F750.

I have ~250 sq/ft of exterior wall to cover. Looking at an outfit on that sells aluminum slats 5.25" x 60" around $13.11 sq/ft would cost me $3300, higher than I would like. It seems it's more than I need.

I have looked at exterior ACM (aluminum composite material) panels, used on the exterior of office buildings/skyscrapers, etc. Found a panel, 1mm aluminum on both sides and 4mm plywood core, that was about $6.50 sq/ft and I thought it was too high. I'm hoping to go with something about half that cost, under $3 sq/ft

 

[LeeRoy Jenkems]

Not sure this is for me. I don't want to say I'm building on the cheap, because in some areas I'm spending a lot, but in some areas I don't want to spend too much either. After all, this is all going on a Deuce, not a Ford F750.

I have ~250 sq/ft of exterior wall to cover. Looking at an outfit on that sells aluminum slats 5.25" x 60" around $13.11 sq/ft would cost me $3300, higher than I would like. It seems it's more than I need.

I have looked at exterior ACM (aluminum composite material) panels, used on the exterior of office buildings/skyscrapers, etc. Found a panel, 1mm aluminum on both sides and 4mm plywood core, that was about $6.50 sq/ft and I thought it was too high. I'm hoping to go with something about half that cost, under $3 sq/ft

Pretty pricey stuff. You could just do like thin gauge 3003 aluminum skin. It'd be pretty cheap. And give you a good radiant barrier. Then polyiso foam board on the inside for insulation. It's like R6 per inch, not bad.

 

[montaillou]

Yeah, the exterior cladding I'm still not sure what it's gonna be. I'll probably use 5052 aluminum for any exterior, it has the best corrosion resistance (of the 3 grades that I see commonly sold). 5052 is also cheaper, though I don't know the metals market and maybe there's a reason for this. I will have some insulation, probably about 1-1.5" of expanding foam.

I want a 1/4" ish exterior because I can see this thing going through woods and hitting branches. A thin skin that is common on RV's would probably puncture. Also think about the idea of security, not that I can stop people, but if they make enough racket, take enough time I can wake up, grab my long land pattern brown bess replica .68 caliber and scare the crap out of someone.

 

[LeeRoy Jenkems]

Yeah, the exterior cladding I'm still not sure what it's gonna be. I'll probably use 5052 aluminum for any exterior, it has the best corrosion resistance (of the 3 grades that I see commonly sold). 5052 is also cheaper, though I don't know the metals market and maybe there's a reason for this. I will have some insulation, probably about 1-1.5" of expanding foam.

I want a 1/4" ish exterior because I can see this thing going through woods and hitting branches. A thin skin that is common on RV's would probably puncture. Also think about the idea of security, not that I can stop people, but if they make enough racket, take enough time I can wake up, grab my long land pattern brown bess replica .68 caliber and scare the crap out of someone.

You can get "exterior grade" 5052 that is already clear anodized(looks like plain aluminum basically), or anodized in other colors. But yeah it's going to be a cost vs durability dichotomy. You can always go with ribbed roof metal, it's only about $1/ft.

 

[montaillou]

You can always go with ribbed roof metal, it's only about $1/ft.

Yeah, that is cheap stuff. I was looking at fencing some land recently and corrugated metal was cheaper than wood. Not sure how to seal it though. Most of the roof will be covered with solar panels so the material can be pretty thin, I just need it sealed off from the elements.

 

[LeeRoy Jenkems]

Yeah, that is cheap stuff. I was looking at fencing some land recently and corrugated metal was cheaper than wood. Not sure how to seal it though. Most of the roof will be covered with solar panels so the material can be pretty thin, I just need it sealed off from the elements.

With that particular stuff, they make things called "closure strips" that are these foam strips with the same profile as the metal so they squish in nicely. Or you can just use expanding foam on the high ribs. Also the actual metal trims used with that have geometry made to divert moisture. Like for doors/windows, you can get "J trim". And the screws used have rubber gaskets so they seal up when torqued down.

As far as stopping drafts, you can get good results with foam board and taping the seams with foil or tyvek tape. Cutting down air drafts is a huuuuge deal.

 

[JW7tonWY]

I have enjoyed this thread. Please review my plan and tell me what you think - I am still going thru the MK23 to insure it's fitness for long-term use. I will be at least part of the time living in this in all four seasons in polar to equatorial environments.

I am starting with a Mk23 7ton. My plan (which may change as this thread all sinks in) was to use 2x2 14 gauge mild steel tubing and then FRP panels with 2 inch foam cores, with plywood stiffeners added to the roof panel. To explain: use the tube as a frame, notch the inside of the FRP panels and insert them into the frame with sikaflex and overlay the corners on the outside with angle pieces of probably aluminum, reinforcing the sikaflex with rivets to the tube frame thru the aluminum, FRP, and into the tube frame. There is a company in Spokane that makes the panels in any length width you want and they make a floor panel too. Mainly used for commercial trucking and refrigerator trucks. they say the panels are structural all by them selves and my square tube frame is not needed - my reason is impact damage, i.e. tree branches hitting the corners. they also make repair panels that can be grafted in with standard fiberglass skills.

To maybe help make clear: make a box insert the panels into the sides of box using appropriate tools cut in windows, door and vents as needed on site using hot knife and trimmed to fit with treated wood to internally frame between the panels for openings sealed with layer of fiberglass. The center material below would be the roof. The exterior finish can be spec.'d to your needs I plan on coating the outside with spray on epoxy bedliner over a primed fiberglass surface, the interior can also be spec.'d to work with what you want, thinking clear resin over the plywood. The thickness of the plywood sheeting is also at your spec.

I am in the middle of Wyoming, everything is a long way away, so driving the Mk to Spokane to pick up the panels seems like the closest thing for me (860+ miles one way). Steel is a real expense here (cost to transport), will probably have to drive to Denver (250 miles +/-) to get a decent deal on it still looking at that. 150 miles away is like just the next town over around here so my transport distances are extreme compared to most in this thread.

picture of product, looking at the two panels on the left. albeit in different thickness.



Company's Webpage:

FRP Panels | The Composite Panel People | Fiber-Tech Industries

Fiber-tech manufactures composite panels & fiberglass reinforced panels for all markets & applications. Request a quote or contact us to learn more.

www.fiber-tech.net

 

[montaillou]

Y'know I was in a different place, financially, when I bought my Deuce. MTVR would be real nice for my goals. With your 7 ton off-road rating, you can pretty much use anything. Another MTVR thread here, the builder estimated the wood weight from building at 1.5 tons.

I have seen those FRP structural panels and they seem a good way to go - too heavy for me though. I plan on using square (or rectangular) tubing - spacing will depend on what I decide to use for my exterior. I'm worried about branches as well. Cost of metals are up sharply, though maybe they'll drop by the time I need it (6 mo+), so maybe something with a tough plastic coating.

 

[JW7tonWY]

inversely while I can put on all the weight I want on the 7 ton, if it gets to big and heavy there are a lot of dirt roads with low weight limits on them I won't get to travel. So I do have weight limits to consider. I was hoping with only the corners having steel the FRP panels doing the rest the weights would balance out and still provide the insulation and low thermal conductance I want. Thank you for your comments.

 

[Another Ahab]

I'm worried about branches as well. Cost of metals are up sharply, though maybe they'll drop by the time I need it (6 mo+), so maybe something with a tough plastic coating.

Anything plastic (polymerized petroleum) has GOT to have UV-inhibitors of some kind.

Otherwise it's gone before you know it.

Sunshine is sweet, but it is TOUGH on certain product.

 

[montaillou]

Anything plastic (polymerized petroleum) has GOT to have UV-inhibitors of some kind.

There are UV coatings.

However, due to the issues in Texas recently, all plastics are through the roof - seems there's lots of chemical plants in a state with (usually) low electrical costs close to oil production.

Metal will keep going up though at a certain point it will level off when it gets high enough that imported metal will be profitable even with the tariffs.