No Structural Wood - So Many Questions

[8]

Has anyone considered building with no structural wood...not even in the floor? Items like windows and doors could easily be made to have a frame (possibly wood) that sandwiches the edges of the opening in the foam wall. (It would be like the way a drain is screwed into a hole in the bottom of a sink but it is really just screwed into it's other half and some putty is used to keep the water from leaking.) I think it could be done, but the only engineering question I have not figured out would be how to attach a hatch.

Could a floor be strong enough with just foam, cloth, and glue? Maybe additional strips of foam/cloth/glue (fcg?) reinforcement would be enough. I would probably want a layer of thin wood placed (not attached) on top just to spread the load of a knee (or a leg on a dutch oven) and make it easier to sweep clean. Would a drop floor in all foam actually be stronger due to the box shape? How much could it overhang the trailer frame? How would it attach to the frame? Would a sleeve over the bolt be enough to keep the bolt from compressing the foam? If so, would a huge washer on the top and bottom be enough to spread the load? How do people handle the bolt heads that hold the HF trailer together when they add a floor on top. Do they drill recesses when they use plywood so the board lays directly on the frame or do they let it sit on top of all the bolt heads leaving an air gap? I would guess with an all foam floor it would support better with recesses for the bolt heads.

Has anyone made a foamie and then covered it with aluminum? If you did, and you used no wood whatsoever, how would you attach the edge trim? If the windows were made as mentioned above, the aluminum could be floated and clamped under the window and door trim along with the wall, but that does not help with the outer edges.

I have been really slow with my build. I have finally finished the HF frame assembly and it has only been 16 months since I purchased it. (Although when I purchased it I had absolutely no room in the garage to assemble it. Thanks to Craigslist, I have enough room and cash to do the build. My trash is someone else's treasure..) It has an extended tongue, the frame is assembled as a 4x10, and it has shocks installed. It is way overkill if I change my mind and make a foamie on my 1700 lb HF frame. My TV was traded in last Summer so I need to get a hitch installed on another vehicle. Life gets in the way of life sometimes.

[8]

Hey! My post pushed the Foamies index to two pages! Sounds like cause for celebration.

[eaglesdare]

my build has very little wood. no frame at all. i think i have 5 spars and a bulk head 1/2 wall. that is all the wood, besides the wood floor. i am not sure i would trust a foam covered floor. i think compression might warp it, and i am not sure how much weight it would take. i don't want to test that one.
i dont even have a door or window frame. oh i do have some wood on the hatch, but that is just the spars, the rest of the build is all foam and canvas, and of course gallons of glue.

if you build a foamie, make sure to take pics.

[Wobbly Wheels]

I'm using a foam/ply sandwich for the floor. The foam on its own has no way to carry the loading between the trailer frames. A little bit of wood can be a good thing as it can provide more stiffness than foam alone and (just a guess here) more than foam/canvas as well, though at a penalty of weight, cost, and longer build time. Still, I've got the first section of floor done and I think the increased weight (which I'm trying to keep to a minimum) is worth the increased stiffness.

In my build thread (2nd page), there are a couple pics of the door I made for mine showing the amount of deflection with a bunch of weight loaded onto it. That being said, I'm also using epoxy and glass rather than canvas.

[mikeschn]

I'm thinking about covering my next foamie with aluminum. since I plan on putting screws into the sides, I am thinking about putting a 1x2 "stud" in the foam walls every 2 feet. I am also thinking about laminating a 1x2 stud around the profile to attach the trim to.

At that point you might ask, is that still a foamie? I would say yes, because I am using foamie techniques to build it.

Mike...

[GPW]

Simple Foamie Rule #2, The more wood you have , the more chance of Rot ...

[GPW]

Here's an idea !!! Anyone ever think of laminating the foam with Cardboard ... No, not the corrugated kind , but the gray kind found on writing tablet backs ... Very Strong , and you can buy it in Big sheets, Cheap ... we know how to make it waterproof ...
Wood , cardboard , same material (cellulose fibers ) , although the locked fibers of the cardboard might be even stronger than wood of the same thickness... Certainly Thrifty , and remarkably easy to paint and finish smoothly ... Just might make a nice interior finish... covering foam imperfections and kerfing slots ... Once it gets sealed, glued, painted it becomes very TOUGH ...
just something else to play around with ...

[mikeschn]

Simple Foamie Rule #2, The more wood you have , the more chance of Rot ...

GPW,

Where is your list of rules?

Mike...

[8]

GPW - The rot factor is what I was thinking of most. The mistake forgiveness of foam helps too.

Brian - Looking at your picture showing the deflection, it does not look that bad considering there is a big window hole cut out of it. With the drop floor, with the exception of the dropped floor itself, there should not be that big of an area not supported by the trailer frame itself. Currently there are two 2'x4' openings and a 6'x4' opening. The 2'x4' openings should be no problem. The 6'x4' opening would have the drop floor. The drop floor would have the largest contiguous unsupported span at just under 4'x4'. Personally, I will experiment first. Somewhere around here I saw a picture showing how a flat panel can be reinforced from behind by adding an additional strip of foam and covering that with cloth/glue or fiber/epoxy.

[GPW]

Sorry , I just made that up ... but it makes sense huh ???
No rules really ... This has all developed with the ideas and experiences of all the participants here ... like collective brainstorming , sorta ' ...

8, much yet to be explored !!!

[8]

Here is an image similar to an image I saw elsewhere but cannot find. The dotted lines are the cloth/glue or fiber/resin. The ridges could be added under the floor in areas needing extra reinforcement. They should run lengthwise across the span to be reinforced to thicken that area. If it is needed in both directions then maybe a big "X" or grid would be used.

[GPW]

8, that'll work !!!

[GPW]

8, when in doubt , always add More foam ... Remember , twice as thick is 8 times as Strong !!! ... and I didn't make that up ...

[8]

So, if 2 inches is placed on top of the frame, and each recess had another panel the thickness of the frame itself, that would be pretty strong.

[GPW]

Sure would be ... strong enough for what though ??? I think most of us aren't going to be jumping up and down on the floors , and they are supported by the trailers cross members too ...

It would tend to dent from knees , even canvassed ... 1/8" Masonite would fix that , or thin plywood ... or maybe a fiberglass panel ???