Pro-Rig V2.0 - Home Built Compact Composite Pop-up

[CoyoteThistle]

Well, haven't updated this thread in a while because there hasn't been much to report. Few minor trips here and there but I've mostly been busy with work and distracted by life. Anyway, a trip last week up the the east side of the Sierra's has prompted me into project action. It all started nice.



First, the new camper mounts to the sliders worked great until they didn't. The idea is super solid but as noted, loading bolts in that direction is not very strong. Passenger side snapped. Having the extra mounting points really stabilized the camper though so I'll go to the trouble of making some proper steel brackets to replace the eye-bolts. I'll have to bug my brother and see if he has his welding rig up and running these days. Camper is still bolted through the floor and chained to the bumper so I just removed the new mounts for now.

Then the storms came in. Now, I've camped in snowy conditions several times and never had big issues. This time however, the combination of wet, heavy snow mixed with rain and strong winds led to a poor camping experience. Caused me to miss out on two potentially good powder days. Not acceptable!

Biggest problem was condensation - humid 33 degrees and heavy snow/rain mix made things inside wet (plus wet clothes hanging to dry). Living and sleeping with the pop-up down for the most part. Running the heater helps but the thing runs almost non-stop to keep the camper at about 50 degrees when it is in the low 30's out. The bottom line is I have too many cold bridges (point sources for condensation) and not enough insulation, especially on the slide up (condensation on the walls). The panels I used have an R-value of about 3 which just isn't good enough it turns out. On top of that, the seal between the slide-up and camper still sucks - this is probably my biggest problem. I also decided I hate the PVC fabric on the pop-up. Gets crusty when cold among other problems. Do Four-wheel Camper and others use this because it is cheap? There must be something better. I ordered some fabric samples from Seattle Fabrics but if others have ideas, I'm all ears.

Driving home I pondered how to change the camper. Convinced myself the slide-up has to go to make it a winter-friendly camper. Played with the design frantically upon my return home. I like the low height when driving but that would have to be sacrificed if I abandoned the slide-up. Not happy with the compromises of a taller camper, I then had a slight revelation - the current design isn't the problem, the current execution is the problem. I need a better seal around the slide-up, better insulation on the roof and slide-up walls especially, and I need to eliminate all the thru-bolts in the roof and walls.

Extra insulation means adding thickness to the walls. If I abandon the current slide-up "seal" system, I'll have a 1-1/4" gap between camper and slide-up. That gives me space for about 1/2" of insulation. Best foam I could find has an R-value of 3. Then I came upon Vacuum Insulation Panels (VIP's). These things are kind of amazing. The 15mm (0.59") thick ones made by Panasonic have effective R-values between 14 and 23. They come in a half dozen or so sizes. Bigger panels have higher R-values. There is some thermal bridging around the edges of the panels so bigger panels with lower edge to core ration average out better. The R-value in the center of the panel is 45! That goes to 66 for the 24mm thick panels (20-32 effective R). The catches are, they are not cheap and with the fixed panel sizes, you have to fill in the rest of the area with foam board. The available sizes worked out pretty well for my wall and ceiling dimensions and I think I can cover about 3/4 of the area with VIP's with an average R-value close to 20. The rest in foam at 3. I think I can increase my insulation from a 3 to something between 10 and 15. I ordered panels here - will report back on how it goes. I'll need to cover the insulation of course to finish the interior and protect the VIPs from puncture. I'd like to use thin FRP paneling (goes by the name Filon), but I haven't been able to source it locally and shipping is $$$. Other options are 1/16" plywood (can't find locally), 1/8" plywood (local source, but getting a bit heavy), or something like marine vinyl or headliner material. Plywood means lots of painting (yech!). Fabric would be very light-weight but not as protective of the panels (i.e., no indoor dart tournaments).

Working on ideas for the slide-up seal. I have one wacky idea but I want to try simple first.

Eliminating thru-bolts should be pretty easy (mostly) but will require removal of the roof.

Oh, the one thing that did get a good test and worked well is the LiFePbattery warming system. Need to report on that at some point.

 

[DzlToy]

Panasonic U-Vacua VIPs are one of the few readily available to consumers. Most companies build to order and don't like small fish in a big pond, VIPs are VERY fragile. Consider covering them with Aliphatic Polyurea or fiberglass and resin. A tear or puncture leaves you with the R-value of the core material.

Seal all air gaps around doors, windows, latches, water fills and the like. Add Lizard Skin or Temp Coat radiant barrier coatings.

Edit: Commercial magnetic seals are also an option. Look at your freezer.

 

[RAM5500 CAMPERTHING]

If your current furnace/heater propane?

Switching to a diesel heater like an Espar will help tremdously with condensation.

It’s not a cure all, but it helps a ton. It’s a MUCH drier heat

my .02

 

[ITTOG]

Sorry to hear of the issues but glad you are sticking with it and working on a solution. I look forward to seeing that here.

A simple solution for the seal, just while you our trying out things would be to stuff some insulation in the gap. I have seen sealed insulation (ie wrapped with a cloth) so you don't get fiberglass on you.

 

[CoyoteThistle]

Panasonic U-Vacua VIPs are one of the few readily available to consumers. Most companies build to order and don't like small fish in a big pond, VIPs are VERY fragile. Consider covering them with Aliphatic Polyurea or fiberglass and resin. A tear or puncture leaves you with the R-value of the core material.

Seal all air gaps around doors, windows, latches, water fills and the like. Add Lizard Skin or Temp Coat radiant barrier coatings.

Edit: Commercial magnetic seals are also an option. Look at your freezer.

I'm not going to do wet layup, too much work to sand and finish and would require deconstruction of the camper requiring extra garage space that I don't have. I can see why that is a safe way to go though. Do you see an issue with covering them with FRP panel or plywood? I was thinking of attaching the VIP and foam panels to the walls/ceiling with VHB tape and then using VHB to attach the covering to the insulation. I could arrange it so the outer skin only sticks to the foam board if you think that would be safer? The foam is 0.035" thicker than the VIP so this approach would make it all simpler.

If your current furnace/heater propane?

Switching to a diesel heater like an Espar will help tremdously with condensation.

It’s not a cure all, but it helps a ton. It’s a MUCH drier heat

my .02

I have a Propex propane heater. It draws and expels combustion air from/to outside so it blows very dry air. Is diesel that much drier than this type?

Sorry to hear of the issues but glad you are sticking with it and working on a solution. I look forward to seeing that here.

A simple solution for the seal, just while you our trying out things would be to stuff some insulation in the gap. I have seen sealed insulation (ie wrapped with a cloth) so you don't get fiberglass on you.

Yeah, now that you mention it, the most effective approach I've used is to stuff some long 2" X 2" scraps of foam I have from trimming for the seat cushions into the gap. Effective but not very elegant That's a good reminder that I can fall back on that in the meantime while this is a work in progress - good call!

 

[DzlToy]

The issue really is the film or the bag wrapping the fiberglass or fumed silica core. I don't recall off hand if Panasonic uses a metalized bag or just a few layers of plastic bag (think: counter top home vacuum sealer on steroids), but the film is thin and not very strong. So, if you glue this bag to FRP or Filon and the "skin" moves, the bag is stressed and will soon fail. Small vibrations over thousands of miles will micro-tear the bag and your vacuum will be lost. If you can encase or pot the VIP in something like a hard cell phone case, e.g. LifeCase or Otterbox, so there isn't any load on the core, which is quite fragile, or the thin bag/film.

I spoke with an application engineer a few years ago when I first started looking into VIPs and he noted there are special adhesives that allow the VIP bags to bond to a structural backer, think of setting subway tile in a bathroom. The films can also be heated until they are tacky and 'stuck' to some plastics. Obviously, this is quite tricky and paying the company to do it was quite exhorbitant, so I tossed the idea altogether.

I came up with the polyurea idea after seeing some XPS foam sheets glued into blocks and rolled with Monstaliner. They were quite resilient. Personally, I would choose something like that over Filon. Can you make a 'shadow box' out of Filon or ABS sheet and drop the VIP into it in a manner that keeps the VIP safe and stable? What about a tic-tac-toe board of sorts with the VIPs inserted into the pockets?

 

[CoyoteThistle]

Looks like they are shiny and metallic.

What about this:
1. "paint" one side of the VIP with polyurea or epoxy (maybe both sides is a better idea - encase the whole thing?)
2. use VHB on the painted side to attach to the inner camper wall (which is honeycomb core composite and quite stiff)
3. Don't attach VIP to the Filon skin (leave small gap), attach skin to foam insulation with VHB

Seems like this would isolate vibrations through a reinforced side of the VIP and avoid any stress caused by differential movement of the camper wall and inner skin?

I appreciate the thoughts! I haven't found an example of anyone using this in a camper yet so I'm once again flying blind!

 

[DzlToy]

I am not in your shoes and don't know the details of your camper build, but some combination of what Coyote and I posted seems to be a good starting point for protecting and isolating the panel. If I were to use a VHB or two sided tape, I would obtain one with a bit of "foam" in the middle to damp vibration. Is this sufficient? I don't know, I am waiting on you to tell me how all of this turns out.

Edit: Is there a reason that you cannot just spray, brush or roll the whole VIP in DIY bedliner? Do not buy the spray can "bedliner", it sucks.

 

[CoyoteThistle]

I like the bedliner idea! Something that stays a little flexible seems appealing. I'll have to see if they make a non non-slip version for better tape adhesion. I was thinking the same thing on the foamy tape

 

[java]

I think you should look at sealing the gap as a first step.

My walls are 1.75" of polyiso, but a cold bridge every 12". So I'd say R7 maybe? Roof is a lot more though. My heat doesn't run constantly.

For humidity, I leave the roof fan on the low. Burns a bit more gas heating, but helps a fair bit.

Sent from my SM-G973U using Tapatalk

 

[CoyoteThistle]

Yeah, you're right Java. The gap is the biggest problem right now.

My simplest design is to have a downward facing wedge-shaped strip of some soft foam around the top of the camper edge and an upward facing wedge of the same stuff around the lower edge of the slide-up. When the slide up comes all the way up, they "mate" and form a roughly rectangular foam seal that is 1-2" thick (in the vertical). If that made sense, does anyone have a suggestion for the foam material to use and how to attach it to the wall? I've looked at lots of weather stripping and haven't really seen a wedge. The gap after adding insulation to the walls will be about 1/2" around most of the camper.

 

[DzlToy]

The shape to which you are referring is called a French cleat.

Do not use Polyisocyanurate; it is quite crumbly. The same is true for Styrofoam (EPS). Polyurethane foam does not have a great Long Term R-value (5 years out), so that leaves XPS and some specialty foams that probably aren't great for seals. If you could figure out how to cut and bond it, memory foam or Latex foam could be a great option. Both are quite dense, yet deformable and when "squished" together, should form a fairly good seal in a small space.

Have you considered a magnetic flange seal, e.g. refrigerator door? The R-value isn't great, but properly spec'd and fitted, they are indeed air tight.

 

[java]

Don't worry about the insulation as much as stopping the draft IMO. towels will get the job done as needed. Not elegant, but it works and is testable to try anyway

Sent from my SM-G973U using Tapatalk

 

[CoyoteThistle]

Had to look up the magnetic flange seal. No wonder my freezer stays closed so well! Who knew. That would be slick but it looks like it requires a fair amount of metal (Al extrusion to hold seal and something ferrous to stick to?) I'd like to get all the metal out of that gap if I can. Condensation, cold bridge, etc. Additionally, the gap varies in width by a 1/4" or so depending on where you are, something soft and squishy would work well with the imperfect gap.

I was thinking EPDM weather stripping but I haven't found the right shape. I'd have to cut an angle into some rectangular stuff I think. Latex foam is appealing, softer and would squish together nicely. I've got some laying around that I can test some adhesives on. Neoprene just occurred to me too. durable but generally stiffer than latex. Google time...

Yes, draft-free is the priority (which also means bug-proof outside of winter, which is key).

 

[CoyoteThistle]

Okay, progress is being made. First step was to get all the old slide-up seal material out of the gap. No small amount of "stuff" in there.


It was interesting to test the strength of the VHB tape I used to hold those brush seals in. I was super impressed, those things were on there good. Using a gasket scraper and a hammer and starting at one end made removal pretty easy though. Some scraper time to clean up some adhesive and tape pieces that were left behind and now it's all clean. The rest of that pile was the original seal system which had the dual function (or only function since it was a lousy seal) of stopping the slide-up from raising too high. Now that I have the extra weight of the vent and bigger solar panel on the roof, there's enough weight up there that the spring lifters are overwhelmed (just) so that it's is a non-issue now.

Insulation arrived and I got to check out the VIP's. Different outer shell on each side:


The white stuff seems real thin and delicate (but hard to say). The reflective layer that is wrapping around the edges covers the other side:


This stuff is much heavier duty. Mylar maybe? Seems to be about as thick as maybe a Ziploc freezer bag. I assume this is the side I will want to mount to the wall. I'm still thinking of coating it with epoxy to protect the vacuum-holding material from stress on the taped side, but it might not be necessary now that I see this material. And in case you are curious, they are not light weight. Not heavy, but compared to foam board of the same thickness, there's a huge difference. Speaking of which, that came today too:


Not many choices in foam board insulation to be found in SoCal and shipping 4'X8' sheets is $$$. Home Depot to the rescue with a box of 2'X4' sheets shipped to the local store. R3 this stuff says and 16mm thick. the VIP's are supposed to be 15mm but in actuality are almost 17mm (those non-vacuumed wraparound strips seem to be the difference, the insulation part itself seems true to 15mm).

I also made more work for myself by looking more closely at exterior nooks and crannies. Long story short, the camper is in the garage and it's gonna get a fresh paint job. I'm going with Raptor Liner, which seems most popular with the van folks. I want to change the color anyway and this approach will better protect the structure of the camper from moisture I think. Will hide a lot of the little imperfections in the finish as well I hope. Lots of sanding, taping, and prepping in my future...