Help me find a good class B or B+

[BBQ]

Originally Posted by Davydd

For once I agree with GeorgeRa about foam insulation. Even Advanced RV tried it and removed it from a van because of skin distortion.

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There are ways to spray foam without distorting the skin. I am surprised ARV haven't engaged a professional to do it. Maybe they have found a better solution than spray foam.


ps. I am not endorsing spray foam or suggesting it is better than whatever ARV is using right now.

[GeorgeRa]

Originally Posted by Technomadness

Thinsulate is not something I’m opposed to but I’m missing the advantages of it over polyisocuranate. Seems more expensive and thinner.
At any rate it’s the nooks and crannies and the structural sheet metal ribs/supports that’s the challenge. I understand the buckling issue can be fixed by using foam that expands less? Window sealant I think?
Window sealant is not an insulating material. Thinsulate is easier to install, easier to remove, easier to deal with in case of accident, it is a combo of sound blocking and thermal insulation. Don’t forget that IR reflecting layers are useless without IR which need an air gap.
I’m kicking around the idea of making a unified wall structure that doesn’t try to fit the curve if the van wall. Just straight up for so many feet then a fixed angle for so many feet to the ceiling. I can insulate that, and fit it to the sides and leave air gaps in the rib space or just fill those and not worry about the nooks and crannies. Basically a shell wishing the van body, structurally connected to it, thermally isolated. I would lose two inches of width for every inch of insulation, but it could be pretty modular. 80/20 May make this easy to build. Not ideal but it might be worth the tradeoff for build optimization.
The first question I would ask is - how many windows do you want. I wanted all so I started with a passenger van. All lower cabinetry are below bottoms of the windows and I have upper O/H cabinets above. All lower cabinetry is attached to the floor (except I used 1 seat belt wall attachment hole for the electrical cabinet) utilizing factory threaded mounts. It takes me 15 min. to remove the galley or the rock & roll bed, all reasonably modular.
Someone in the past posted a 3-month long conversion on a 10-min. video. It took over 3 minutes to trim, 30% of work was trimming which is why I started with the passenger van, fit and finish by Daimler with all of their engineering and tooling capability. It took a while to figure out how to attach O/H cabinets, one fellow from the Sprinter Forum recently posted a video how to attach O/H over the headliner using my design. See the video
The more I think about it the more I’m convinced this needs to be four season capable and I am gonna have to DIY. If I’m going that route I’m going to design for replication. So if the van is totaled I can recreate it very fast, even use the modules in the next van. This may not be practical but looks like it is at this point. Won’t be able to tell until I have the van in hand.
If the van is damaged or totaled – a key point, for just damage don’t use foam insulation, in case of complete scrap maximizing modularity will help reuse of most cabinets, bolting to the floor only is critical.
I saw someone using fiberglass angle to isolate internal structural aluminum from the van structure and was stealing that idea, only my thought is to use UHMW. UHMW is polypropylene of high molecular weight, and can be worked like wood, is electrically and thermally jnsulating but not rigid and brittle like fiberglass angle can be. (Tears rather than sheers). It might be a bad idea but I’ve worked with it in very high stress environments before— battlebots— and it can take a beating from an opponents weapon.
By the way, I’m pretty Ute the guy I saw using Fiberglass angle mentioned he got the idea on the sprinter forums from a George, so maybe that was you— it’s a great idea!

Indeed, I used structural fiberglass angle and shared it on the Sprinter site. UHMW PE or PP are not structural materials, huge coefficient of thermal expansion and they flow in time. I used HDPE extensively for all finish work and material is not a structural. Great material because it is homogenous, edges don’t require a finishing step.
I agree best for insulation would be a class C with well made insulation. Good structural integrity could come from vacuum forming or solid fiberglass. If Bigfoot we’re still making motorhome a id be keen on that. I have considered remodeling an older fiberglass RV, but that’s looking like several weeks to get to the point where I can start building. (Eg have to tear out the interior, clean and repair it etc.)
Anyway, having looked at a bunch of RVs, right now when I see a TRAVATO (about $80k Street price) I figure it’s worth the $40k over the cost of a bare pro-master to do it myself.
Though I’m torn. I’d rather buy than build, but I’d rather spend the time doing it right upfront than deal with the consequences of their low quality down the road.
My mistakes will be a lot more fun to deal with than theirs!
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It took solid 3-4 month to convert my van spread over a couple of years to get to a campable state. I am putting final touches on the second table attached to the galley by Lagun, last key item. A lot of fun and a lot of frustration, but we ended up with precisely what we wanted.
Regarding aluminum framing, I used primarily 15 series 80/20, but would consider some 10 series or Quick Frame. Quick frame is gaining popularity, Galerie "Fahrzeuge" - Terracamper - Die Bus-Manufaktur from Germany is using it and I think Sportsmobile is partnering with them for their Mercedes Metris.

https://www.youtube.com/watch?v=yfK4SDDFkrI

[Davydd]

Originally Posted by BBQ

There are ways to spray foam without distorting the skin. I am surprised ARV haven't engaged a professional to do it. Maybe they have found a better solution than spray foam.


ps. I am not endorsing spray foam or suggesting it is better than whatever ARV is using right now.

The only foam I would ever use is a closed cell polyisocyanurate and I know it is difficult to control because of its expansion properties. In my career I investigated every spray foam out there for buildings and concluded if it's white it's worthless. That's a general statement but after checking everything I could I found repeated fraudulent claims. And many of those were in the specifier's bible, Sweet's catalogs. I had everything tested at an independent testing laboratory as well as simple in-house tests. I've been retired for 10 years so much can change but I learned to be suspicious of the industry.

I saw the van they sprayed after they removed the insulation and they told me they concluded it was not worth it. That was a few years ago. Skin distortion is one thing. Whether they had a professional sprayer or not, I don't know. There is a lot of electrical and other stuff running through the outer walls and what they currently do with the Hushmat is install it prior. It could be they concluded it wasn't practical for several reasons. Distortion, cost, production, sequence, time, etc. Who knows? I'm not privy to their decisions.

[Saldar]

Originally Posted by Davydd

I saw the van they sprayed after they removed the insulation and they told me they concluded it was not worth it. That was a few years ago. Skin distortion is one thing.

What is skin distortion, relating to foam?

[Davydd]

Originally Posted by Saldar

What is skin distortion, relating to foam?

Bulging outward from the pressure of the expanding foam while it cures.

[BBQ]

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Van Life 2: Insulation & Finishes

[Phoebe3]

Originally Posted by BBQ

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Van Life 2: Insulation & Finishes

YIKES!

[Technomadness]

Originally Posted by GeorgeRa

It took solid 3-4 month to convert my van spread over a couple of years to get to a campable state. I am putting final touches on the second table attached to the galley by Lagun, last key item. A lot of fun and a lot of frustration, but we ended up with precisely what we wanted.
Regarding aluminum framing, I used primarily 15 series 80/20, but would consider some 10 series or Quick Frame. Quick frame is gaining popularity, Galerie "Fahrzeuge" - Terracamper - Die Bus-Manufaktur from Germany is using it and I think Sportsmobile is partnering with them for their Mercedes Metris.

I’ve been working with maker frame (a smaller version of 80/20 that is 15mm on a side) for awhile and love it. Quick frame seems a lot less robust as the plastic end pieces can slip out of the tube - at least in the examples I’ve seen.

I am planning on 15 series 80/20 for the structural cage (eg what connects to the van struts) and maybe 1 inch or smaller for other work.

I like that it’s bolted together and expect that to be more long term reliable than most any other construction method.

Earlier I was misunderstanding what thinsulate is, apparently there’s a variety of products with that in the name or that have that material. I can think of nothing better for the interiors of the support volume, but as of right now plan polyisocuranate for the large spaces. There will be an air gap but I am not basing my plans on it because I’m not using reflectix, or don’t plan to at this point.



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[Technomadness]

So at this point I have decided to DIY. I know enough of the required skills at this point and I’m tired of all the compromises and high cost of buying an off the shelf RV.

So next month I’m planning to buy a ProMaster off the lot and start the month after. Gonna spend 60 days doing the initial build then road test it for awhile.

Another nice thing about 80/20, I can make many things modular and reconfigure if I don’t like them.


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[Technomadness]

Originally Posted by Davydd

The only foam I would ever use is a closed cell polyisocyanurate and I know it is difficult to control because of its expansion properties. In my career I investigated every spray foam out there for buildings and concluded if it's white it's worthless.

So if you used polyisocuranate sheets, what would you use for the gaps around them?






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[Davydd]

Originally Posted by Technomadness

Earlier I was misunderstanding what thinsulate is, apparently there’s a variety of products with that in the name or that have that material. I can think of nothing better for the interiors of the support volume, but as of right now plan polyisocuranate for the large spaces. There will be an air gap but I am not basing my plans on it because I’m not using reflectix, or don’t plan to at this point.

Thinsulate is a proprietary synthetic insulation by 3M company used in a variety of ways. It is not a generic product.

https://www.3m.com/3M/en_US/thinsulate-us/

Do you really understand how to insulate a van in undertaking a DIY project because your above paragraph makes little sense to me.

[GeorgeRa]

More pictures regarding foam and sheet metal interaction. Very tricky to do it without metal distortion, foam needs to be layered, and besides esthetic you are left with VOC. https://sprinter-source.com/forum/sh...am+sheet+metal

[booster]

Those pix are kind of weird. I would expect to see bulges not dents. Did they pop them back in?

[GeorgeRa]

Originally Posted by booster

Those pix are kind of weird. I would expect to see bulges not dents. Did they pop them back in?

There was a lot of discussion regarding this issue, this is what I wrote back then:
“I have no doubts that there are multiple factors which could cause sheet metal deformation:

- Difference of CTE between steel and foam
- Difference of CTE within the foam
- Temperature gradient across the foam thickness
- Foam to sheet metal adhesion
- Foam to steel structure adhesion
- And other I missed,

Many theories can be developed which factors were predominant but one factor is valid without a doubt - in situ developed polyurethane foam caused this warp.

George.”
https://sprinter-source.com/forum/sh...4&postcount=18

[GeorgeRa]

Food for thought. Here are some of the pictures from my build, practically all work was done on CAD, allowing for factory machining of 80/20, tight fit of cabinets, fundamentally trying to minimize mistakes by doing all dimensioning on CAD. One of the objective was minimum weight and we did it.

Overall build https://goo.gl/photos/AZnG63iwMr9u6zLw8
Table https://photos.app.goo.gl/Ey4XSxqnLjWX2nzx1
O/H cabinets https://goo.gl/photos/D6ScLYL9UYFbcw3n8
PV panels installation https://photos.app.goo.gl/NaDXquJwAigYuTBw1
Rock and roll sofa https://goo.gl/photos/UVupnzpkrGAVs4sUA
Use of 80/20 https://goo.gl/photos/Mdqa7sxApbQ5csCQ7
Airtronics D2 https://goo.gl/photos/KHrmetWa81i7jMRT6

And the trip to Yosemite via the weight limited Old Priest Grade, fully loaded including water and us we are way below 7500 lbs. https://goo.gl/photos/o1JZYQASdT59csZ5A

[Davydd]

As GeorgeRa mentioned, there can be a multiple of reasons. It was suggested a professional applicator could overcome this. I'm not sure. The metal skins of vans are extremely prone to distortion. In the right sun you can see where the internal structural ribs are attached.

[Classic Vans]

What about a Winnebago Via? Similar floor plans as TRAVATO 59G? NO?

[Saldar]

Originally Posted by BBQ

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Van Life 2: Insulation & Finishes

Thanks for the illuminating picture. I mentally rejected the possibility of such extreme deformation. I'll never forget now!

[Technomadness]

Originally Posted by Davydd

Thinsulate is a proprietary synthetic insulation by 3M company used in a variety of ways. It is not a generic product.



https://www.3m.com/3M/en_US/thinsulate-us/



Do you really understand how to insulate a van in undertaking a DIY project because your above paragraph makes little sense to me.

Follow your link and select “products” from that page and you will see what I mean, even thinsulate for clothing.


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[Technomadness]

Originally Posted by GeorgeRa

Food for thought. Here are some of the pictures from my build, practically all work was done on CAD, allowing for factory machining of 80/20, tight fit of cabinets, fundamentally trying to minimize mistakes by doing all dimensioning on CAD. One of the objective was minimum weight and we did it.



Overall build https://goo.gl/photos/AZnG63iwMr9u6zLw8

Table https://photos.app.goo.gl/Ey4XSxqnLjWX2nzx1

O/H cabinets https://goo.gl/photos/D6ScLYL9UYFbcw3n8

PV panels installation https://photos.app.goo.gl/NaDXquJwAigYuTBw1

Rock and roll sofa https://goo.gl/photos/UVupnzpkrGAVs4sUA

Use of 80/20 https://goo.gl/photos/Mdqa7sxApbQ5csCQ7

Airtronics D2 https://goo.gl/photos/KHrmetWa81i7jMRT6



And the trip to Yosemite via the weight limited Old Priest Grade, fully loaded including water and us we are way below 7500 lbs. https://goo.gl/photos/o1JZYQASdT59csZ5A

Thanks for this post! So many great tips I just picked up from those pictures, and a great example of what can be done with 80/20!

I’ve worked with UHMW before, but not HDPE. (Both polyethylene) the HDPE looks more rigid and finished, but I won’t have a CNC machine to work it.

I was really curious about the hooks and was going to ask you how you made them, then I saw the reference to this— genius!

https://8020.net/6808.html


PS— like the sliding cabinet doors in the 80/20 groove— but how do you keep them from rattling?

Also saw in one spot where you didn’t have smooth sided 80/20 you filled it in with a grey rubber— is that an off the shelf gasket or something you made?

I’ve been thinking about using the grooves to hold panels, and maybe usingvsome gaskets or UHMW channel in there to hold them firmly— but would have to custom fabricate them it looks like.