Best way to insulate enclosed utility bed?

[thetundrawolf]

Hi,


I am building an elongated 4x4 van, that will be half van, half utility bed. I have not fitted the utility bed to it yet, but soon.

My concern is that, the metal box will act as a sort of reverse heat sink, with the cooling "fins" being the internal shelving.

I saw a product once, to help welders, it was a gel or paste that you could put on a piece of metal to stop the heat from transferring, it worked remarkably well it seemed.

If it could do it to that metal, then maybe something could "stop" the internal "fins" from absorbing cold/heat from the outside... Say maybe silicone caulking/sheeting?

Or, just reflectix, or some hard foam insulation, that wouldn't trap moisture against the metal like expanding foam does.

For insulating bare metal, what is best?
I plan on living in the utility bed portion for quite some time, with my two dogs.

I want to, use possibly a ductless mini split to heat and cool, i will have 1,600W solar, and maybe 6KWH lithium batteries, but just to start. I am not opposed to, and probably will have a dual, gas/electric setup, to especially warm it inside.

Ideas are appreciated.

 

[bullfrog !]

What type of utility bed are you considering? Are you enclosing the top or is it already enclosed? Will the side compartments be accessed from the outside, inside or both? I have seen a pickup topper put on a utility bed as well as a flatbed with wooden board stake sides and a topper to enclose it. Utility beds by their nature are heavy. They tend to really affect your fuel mileage badly. Do you already have the van? A cheap water damaged Class C with a diy transition box to utility bed made out of light weight materials (tnttt.com Poor Mans Fiberglass in the foamies forum) might be worth considering. With space limitations it might be better to simply use a larger heater or cooling system or build a rigid foam box inside and on top the utility bed. If I remember correctly our gasoline engine one ton truck with an open top utility bed got 5 to 7 MPG on a good day. The more we know about you and your goals the better we can answer your questions for sure. Tell us more and pictures really help! I do remember seeing a paint additive that had small foam balls you could add to paint to help insulate. Don’t know if it was effective but you might see if it is still around.

 

[Frood]

Depending on budget maybe consider something like lizard skin?

https://lizardskin.com/

 

[thetundrawolf]

So, the chassis is an 05 Express 3500.

The engine is I believe off of an 01 Silverado 2500, an LQ4 (I think) 6.0 LS.

The transmission is from an 04 Express 3500, and is rebuilt. The transfer case is an NP214(?) I got from a 98 Suburban 3500.

The rear axle is from an 04 3500, is full floating, disc brakes, van width, and has gears of, 3.75 gearing, which is what I wanted, above 4.11, for better mileage on the highway.

The covered utility bed, is from an eighties era Ford one ton van.

I drove to Colorado to pick up, a 4x4 bracket kit, to convert it to a 4x4 van.

It is undergoing a frame spraying, but I may forgo it, just to get it all together soon, before the year is up.
As far as fuel mileage goes, I am hoping for the best possible, with new engine sensors, including O2 sensors, and possibly a custom fuel map for efficiency, but at the end of the day, "It is what it is".

I am not wealthy (Yet!).
I plan on it being a hybrid, camping/work vehicle, maybe even a sort of roaming work van as I tour the USA and see if there is a place I want to settle into permanently.

I plan on, cutting some of the shelving inside, making room for a bed, TV, stove/oven, security system, etc. It'll have 1,600W solar, 5KW+ inverter, propane, septic, black and grey tanks, and I want a minimum of 40 gallons fresh water with RO system, and 60-90 gallons of fuel for the van, plus a smaller inverter generator. Plus, as I said, perhaps a mini split that heats and cools the van.
The lizard skin looks like a great idea, and it is not expensive! That may be what I want, and maybe some thing foam insulation. The solar panels will cover the roof, so it won't get direct sunlight in the summer, but it won't have sunlight for warmth in the winter, either.

 

[bullfrog !]

Solar panels produce heat on their back side which is why most people raise them up a few inches to increase efficiency as they don’t produce as well when hot. I have considered boxing that space below them in with foam walls and circulating air with a computer fan into my living area in winter through two roof vents in winter. Something to experiment with. I think you will regret the 3.73 rear gear with the weight you will be carrying. You actually might get better fuel mileage with the 4.11 and put less wear on the rest of the drivetrain.

 

[maki2]

You can “decouple” metal shelving brackets from the metal frame with a pieces of firm rubber sheeting. The kind you can buy in automotive stores. Not too thick though as you do not want to add any bounce and flexing. Trim pieces of the rubber to size with a pair of utility scissor or knives. Not too time consuming or difficult of a task. A bit of contact cement will hold it in position on the metal until you install the fasteners through it. If you need to put clearance holes through the rubber use a hole punch to make them. Drilling does not create clean holes in rubber.

 

[thetundrawolf]

Solar panels produce heat on their back side which is why most people raise them up a few inches to increase efficiency as they don’t produce as well when hot. I have considered boxing that space below them in with foam walls and circulating air with a computer fan into my living area in winter through two roof vents in winter. Something to experiment with. I think you will regret the 3.73 rear gear with the weight you will be carrying. You actually might get better fuel mileage with the 4.11 and put less wear on the rest of the drivetrain.

I have thought of this, that 4.11 would be better, but this is a "we shall see" thing for now... I may also change to 4.11 just to "see" if there is a difference, but for now, it has 3.75

I may or may not enclose the solar panels, but I doubt it, but that is true and a concern.

 

[LargeMarge]

I like your ambition!
.
a)
Looking at the insides of this ex-FedEx box-truck ad for an upcoming auction, I bet any welder-fabricator could install doors and compartments to any specifications.
GVWR of 16,000#, Cummins 5.9.
.
b)
I stopped for fuel in Junction City, Oregon.
In the next aisle was a plumbing contractor with an enclosed van (similar to this ad (below).
I liked the amount of opening compartments for outside access.
.
I see every vehicle as a residence first, and then transportation or some other secondary purpose.
Weird, eh?
.
I mentioned to the operator:
* "This would make a great camper!"
He quietly replied:
* "I live in back... and work out of it, too."
.

 

[jonyjoe303]

On the roof of my van I removed the headliner and just added rtech foam to the bare metal. I started with 1/2 inch, then went to 1 inch, 2 inch and finally at 3 inches of foam insulation I no longer felt any heat coming from the roof. (hotglued in 1/2 inch layers one on top of the other)
This should work on any bare metal. As long as you don't have any problem with losing some space to the foam it will be a worthwhile way to insulate your van.
I always park in the sun, thats why I wanted the max performance from the insulation I would be using. If you do it you have to cut the insulation into small sections and hotglue it all together like how they attach the tiles on the space shuttle. Foam will hotglue extremely well to bare metal and also to other foam, and dries extremely quickly with no fumes. Hotglue is very rugged and will hold for a long time, all the foam on my roof I installed in 2013/2014 and it is still up there.
In summer I have a small swampcooler keeping my van cool, in winter all the insulation keeps the inside of the van comfortable enough that I havent had to use a heater in almost 4 years. Its rare that I have to sleep in a sleeping bag.
When Installing insulation I use an IR thermometer and anywhere I see heat, I add more foam to that area. In my experience of using it for over 10 years it works extremely well, the more you install the better.

 

[Geneeus]

I don't think that solar panels create heat. They do get hot because of sunlight falling on the dark surface however. I would do some serious research before boxing the "bottom side" even in winter because the cooler they are, the more efficient they become. I think. Maybe.