Initial design

[Tempest]

6'6 wide inside x 6' tall inside x 7' long
T&G the 4' sheets or possibly tenons to get the larger sizes
1/2" treated plywood bottom adheared to 2" foam floor with linoleum flooring(? ) as the camper will be used in deep snow and wet very often.
2' foam for structure, canvas exterior, shower type thin lining on interior walls and ceiling again because of deep snow and wet often.
GG for glueing foam structure
TBII for canvas hoping will be ok for snow
prebuilt door & window (?) No roof vent but can crack door window or regular window for air
Heavier metal angle frame around bottom for attaching to pick up flat bed, small trailer (already own), custom skied sled for pulling through deep snow
No hatch

Instead of kerfing, thinking possibly building a roof form, attaching the front roof section to the sides, then placing a shop heater inside blowing right at the top foam pieces and SLOWLY shaping it to the form???? Again just thinking at this time!!!!

All critique welcome.

[GPW]

Tem’ ... All you have to do is heat the foam to 190F to get it to bend ... You can make a form ( ) or bend it a little at a time ( BendFoam jig) ... Be sure to let the foam cool completely on the form and it will keep that exact shape ... Which actually makes the structure stronger, because the bent foam is no longer stressed and now “neutral in it's new shape .

Not having this “snow” you speak of , but enduring constant High Humidity here, I believe ( JMHO) that you shouldn’t have any trouble with T2 and canvas ... But Foam itself gets brittle at very low temperatures... You may want to test a scrap piece in the freezer... see if it meets your expectations...

[KCStudly]

Some (most?) people have had trouble gluing synthetic fabrics (shower curtain material?) using the water based glues... or, really, any glues? You want a fabric that will soak up the glue. Best to stick with cotton, glue it on, let it dry, then fully saturate it, then paint.

[Tempest]

Thank you for the replies! So 2" hot forming is doable? I'll definitely try a piece in the freezer as we can get well below 0f for days/weeks! There could be times when the camper is sitting in the mts. for weeks. Also good to know about staying with cotton on the inside. Was hoping to laminate the inside material on to the foam prior to installing while the sheets are flat so as not to have to try in a smaller confined space after assembled. Just trying to streamline it a bit. Years ago we built a house using SIPs panels. Unbelievable strong stuff, so know a little about foam use.

[GPW]

“ So 2" hot forming is doable?” Although we have never bent 2” , we have quite easily bent thinner <3/4” foams using a simple jig and a “heat gun” ... So Theoretically , YES !!! But I can’t imagine it would be a one person job for a large part like a full sheet for bending , and it will be difficult to find experienced helpers ( who won’t burn/melt your foam ) In a shop situation with a couple pairs of extra hands it would be easy .... at home , not so much ... The safer idea of a slow low heat ( industrial heating blankets ) would enable home bending , but those are expensive and especially for making just one trailer ... Still puzzled for finding an easy way to do it with stuff you have at home ... maybe slow, gravity bending with some heat lamp bulbs ...


We have “vowed" to finish the insides of all panels BEFORE assembly next time , saves a Lot of harder work after the fact ... Even if your panels are covered to the edge , and an edge that glues to another panel , remember the outer skin is what holds everything together ... so a foam-cloth-foam join would be no problem at all .. maybe even better ? Since you know about SIPS , then you know it’s all about accurate “Planning” ...

[Tempest]

I'm going to play around on the CAD today to see what kind of radius the roof will look like. Wanted to fit cabinets in the upper ends of the roof but now thinking with 2" foam the radius may have to be so large that cabinets won't work. Maybe a cpl different angles from the walls to the roof line would work better to get cabinets in. All my design planning revolves around making it easier and more enjoyable for my better half! Me, I'd build a box and call it good. I definitely plan on skinning the inside of the foam prior, with what ? not sure yet. Thinking of screwing 3/4" wood frame rails to the floor on edge, daddo the bottom edge of the foam to slip over which should allow for more gluing surface. If the top and sides were PMF installed prior to assembly, could a 6" piece of canvas be added as an angle attaching top and sides AFTER assembly??? Would this canvas angle provide the support to make it all one assembly? This way the only interior PMF being done would be the 6" canvas angle and paint.

[ghcoe]

You might look at something like this. If not too drastic it could be done with 2" without kerfing. With 1" should be easy to do just might need to laminate two together if you want a thicker roof.

Profile

drawing.png (8.13 KiB) Viewed 468 times

[Tempest]

ghcoe, I like that profile better than the ones I've come up with so far. After drawing them out, I realize, I don't like the looks of many angles from the sides to the top. I like the rounded edges or one like you've drawn but I need the head height to be highest close to the middle. Thinking maybe a hybrid foam with using say 3/4" wood arcs. 1/8" luan skin on the inside. Daddo the sides and top flat pieces so the luan over laps a cpl inches, then fill the voids between the wood arcs with GS? Then all you'd have to form is the outside radius of the GS to the outside edge of the wood arcs??????? My design is pretty simple but with wanting a standee and then also wanting the certain items that have to be in the camper, I'm realizing that the camper being asthetically pleasing isn't going to happen.

[lthomas987]

As a person who had at least one winter under construction where the temp didn't go over 0degreesF for many many days. I didn't notice any weakness with the foam in situ. I did my kerfing in the summer though so I can't talk of bending in the cold. But my camper has been frozen solid many times and is just fine. So I wouldn't worry about that. Mostly I tried to get the garage up over freezing (35-40F is about as cold as I like to work) before I did much with the trailer. Mind you some of that I did by running a coleman lantern in the camper with me while I was working (that got quite toasty) and I had no windows or doors in yet so no risk of asphyxiation.

[Tempest]

Good to know. Thank you