Folding Foamie Camper a la Casita or Esterel in the Works

[RJ Howell]

As for sandwich panels I am quite happy with 6oz e-fiberglass and epoxy covering over XPS that I did on my build. It is light weight, stable and rigid. If I did that again I would consider other methods, but only after a good testing on samples.
Good luck!
Oleg

I went kinda the same direction as fiberglass over XPS, yet used 2.5oz (thinking weight. Overall, I see no reason not to go heavier cloth (mine may be a bit light) and I'd go about 4oz next time. OP827, curious if you'd go lighter cloth? My Topper I went HF dropcolth outside and bedsheet inside (PMF). Outside used primer, inside TBII to attach. Pro's and Con's to both ways, yet TBII was much cheaper/easier.

My roof I added a rim (inside and out) of 1/4" plywood. Wanted some sort of a mounting surface and a bit of additional stability. Again, fiberglass over.

I'm at a point of it being a toss up PMF vs. Fiberglassing. PMF done well (quality cloth) comes out pretty equal in costs to FG'ing. I look at FG as a very good weather shield. You get away with a lot more 'sins' with PMF and gain a nice looking texture. To me, it comes down to what you wish the final appearance to be.

Following with interest!

[OP827]

.... OP827, curious if you'd go lighter cloth? My Topper I went HF dropcolth outside and bedsheet inside (PMF). Outside used primer, inside TBII to attach. Pro's and Con's to both ways, yet TBII was much cheaper/easier.
...
I'm at a point of it being a toss up PMF vs. Fiberglassing. PMF done well (quality cloth) comes out pretty equal in costs to FG'ing. I look at FG as a very good weather shield. You get away with a lot more 'sins' with PMF and gain a nice looking texture. To me, it comes down to what you wish the final appearance to be. ...

I don't think I would do thinner cloth than 6oz from simply the cost and ease of handling perspective. I found that 6oz is less expensive than thinner cloth and I believe there is not that much weight saving from going thinner especially over XPS. Not much overall weight can be saved going thinner and also I still want a decent protection for the foam. I think 6oz would be an absolute minimum I would want to have as an external skin. If I use thin plywood and FG cloth on top then yes, lighter cloth is ok, but again depends at what cost. My XPStream build is an experiment for minimal sandwich roof structure and folding walls to keep weight low. It was not yet tested in the field to all conditions. One thing I noticed is this foam sandwich roof does not reduce rain noise at all, I can clearly hear it inside the trailer.

I tend to agree with your conclusion about PMF vs. FG costs, but with FG you can (if you want) achieve a car like finish, but then it becomes more expensive than PMF due to 2k automotive coating products that are really expensive.

[dogcatcher]

TT, it may make things easier if you build a little scale model first … Scrap cardboard or foam meat trays work great for “visualizing” how things fit together , or don't …

Build it to a scale something like using a GI Joe figure, the old ones were about 12" The new action figures are 3.75" tall. Using a scale and a figure makes it easier to visualize how it will work in real life. A bigger figure works better. I usually used cereal box cardboard and double it to add stiffness. Elmer's glue and Scotch tape.

[TinkerTailor]

Yes, I did a little model and I think I'm ready to move ahead. Next up is the relatively uninteresting step of firming up my precise measurements for each of the panels and moving parts along with installation of the hitch on my TV and assembly of the trailer, which will be used to pick up the construction materials.

[OP827]

TT, it may make things easier if you build a little scale model first … Scrap cardboard or foam meat trays work great for “visualizing” how things fit together , or don't …

Foam board from dollar store is also working great for modeling.

[TinkerTailor]

Hello all,

So I've been fleshing out the finer details of measurements and such.

I need to decide how much of a gap to leave between each wall and the roof skirt that fits like a sleeve over the assembled walls. FootLoose, who is working on his own version of a folding foamie, has advised me to leave at least 1/8" per side. Does that seem sufficient, or should I up it to 3/16" to be safe?

I don't want it too loose, but I do want it to be easy to handle and set up.

Best -

TT

[Pmullen503]

Things move, expand and contract with heat and humidity, and your beautiful 1/8 gaps now rub. My inset doors fit like a glove with 1/8" gaps when new. A year later I was planing material off the edges that now rub.

Also, plan for whatever you cover that lip with being thicker than you think. PMF, fiberglass will form something like a bead when wrapped around the edge of the skirt.

I'd shoot for no less than 1/4" gaps.

[Tyrtill]

With my foamy my 3/8 original gap rubs. I believe the canvas pulled things tighter as it dried.

[TinkerTailor]

Thanks Pmullen -

I think I will go in the 1/4” direction to be safe! Hitch was delivered today, finished house painting projects yesterday, so I’ll need to get the garage cleaned up a bit and get the trailer assembled and start building.

[TinkerTailor]

Somehow I missed your post, Tyrtill.How badly does it rub?

Good to know- on consideration of what you all and Footloose are sharing, I’m leaning towards 3/8-1/2”.

Thanks again!

[OP827]

...
I need to decide how much of a gap to leave between each wall and the roof skirt that fits like a sleeve over the assembled walls. ...
TT

You might also think about thermal expansion of the roof, especially if it will not have a perimeter wood structure in it. XPS Foam thermally expands significantly more than the wood. I would personally add some wood perimeter and structure to the roof to alleviate the foam shape changes with temperature change. Depending on the temperature the roof part will expand or contract while lower part might not expand at the same rate due to internal structures attached to it and difference in temperature due to different exposure to sun. At least this is what I found in my build, I would rather have some gap vs. jamming while lowering the roof due to thermal contraction. My build roof is covered in fiberglass so it suppose to be a bit more stable and rigid than with PMF covering, I presume. In any case I would fit the roof at a lowest ambient temperature you plan on using the trailer so the roof does not jam during cooler days, or allow/calculate the gap to avoid such jamming.

[TinkerTailor]

Very good to know.

I will have a wood perimeter in the roof for extra stiffness and stability, and the sleeve itself will be 1/4" plywood, so hopefully that will help to limit the expansion/contraction somewhat at the joint.

Since I live on the coast and plan to do ski camping in the trailer in the winter, I won't be able to come close to fitting the roof at my lowest likely ambient temperature. Too bad - that is a great idea. I'll just have to add some more play in the sleeve to accommodate that.

The gap keeps getting bigger and bigger, but much better these changes now than once the roof pieces are already cut and fitted!

[TinkerTailor]

So, the garage is as tidy as it is ever likely to be, and I've begun assembling the HF trailer. I'm trying to decide whether to leave the factory fenders off or not.

I'm leaning toward leaving them off since even with them on, I'll still have to go to the trouble of boxing the wheels into the cabin structure since its width will be more than the wheel width of the trailer.

If you can think of any good reason to put the fenders on, please let me know. I'm going to finish the trailer tomorrow.

Nice to have the project take some tangible form!

[TinkerTailor]

OK, so the HF trailer is built and wired (I left the fenders off).

Once I had it in my garage where everything will be stored, I started thinking about trying to save more space by making the cabin more compact when collapsed. I was considering the suggestion made earlier to simply make separate walls, a roof, and floor panels to be assemble in situ. I have two qualms about that plan, though it would save a ton of space and be simpler to construct (if done without sliding dovetails). The first is that my TV is a CRV, so it's not huge. I'd like to be able to haul clothes and equipment out of the weather in the collapsed camper. The second hesitation is also weather-related. I anticipate setting up at times when snow is falling, and while the Esterel-style setup won't be completely weatherproof, it will be a lot better than having to assemble separate panels from the ground up in the weather. There is another option: instead of having a lower and upper wall, there could be one continuous wall connected to the floor panel by hinges. That is a cool idea and makes setup drier, but doesn't help with the hauling issue.

I was also looking at simplifying construction a bit since my summer is getting away from me. I had calculated the kerfing necessary for my radiused roof and floor. That is of course extra work, but I liked the aesthetics. The radius up top, however, also means that the roof assembly must be 1.5' deep, which adds a lot to the height of the camper when collapsed, so I decided to ditch the curves and go with a simple, completely rectangular box or a rectangular box with a slanted shed roof, both of which could be aestheticized by tapping into the contemporary tiny home vibe. Based on aesthetic preferences as well as better shedding of water in rough weather, I decided to go with the slant-roofed design below.

It's dimensions are pretty close to identical to my earlier design when the camper is set up for sleeping, but when broken down, it is only 2'3" high as opposed to a shade under 4' with my previous plan. That will save a lot of space in the garage. At the same time it will allow me to haul the ice chest, cooking equipment, boxes of clothes, etc. while en route.

The roof will have extra space built into the expansion gaps at the front and back to accommodate the shift from its horizontal position while collapsed to its diagonal placement when set up for camping. I'm going to build the roof last so that I can carefully fit it to the actually existing structure rather than try to plan it exactly ahead of time. If needed, I'm thinking that I could connect the 4 pieces making up the plywood skirt with EPDM roofing rubber to allow for some play, but I don't think that'll be needed. At least I hope not.

I'm getting the basic materials list sorted out for ordering now, though it's proving difficult to get the hitch installed due to family duties, and I'll need the trailer to pick up all the panels.

I'm pretty stoked on the new design, but interested to see if you all notice any fatal flaws, rookie mistakes, etc.

[Postal_Dave]

Looking at your drawing, it reminds me of the camper I built.
http://www.tnttt.com/viewtopic.php?f=50&t=49781

I have solid walls that fold down on three sides and the roof that is connected to the back with a hinge.
It was a good design as far as functionality, but I made it too heavy by using 1/4 inch plywood for the outside of it. I'm a few years older now than when I built it and the roof is too heavy for me to lift alone. I'm getting old and weak.

My next camper is going to be a lot like my old one except a lot lighter.

BTW: I probably missed it, but how do you plan on raising your roof?