If foam alone is good enough for walls..

[Wolfgang92025]

Irving,

My build is 1/4" outside, 3/4" foam and 1/8 inside.
If I was to do it again, I would go 1/8" in and outside. Still plenty strong.

[Irving]

Irving,

My build is 1/4" outside, 3/4" foam and 1/8 inside.
If I was to do it again, I would go 1/8" in and outside. Still plenty strong.

Excellent. Thanks a lot for that. I'm not sure I can get 4 x 8 sheets of 1/8" locally. But may do 7/32" all around..

What did you use for framing? Cut up lengths of 3/4" ply?

[Irving]

http://www.tnttt.com/viewtopic.php?f=55&t=39373 It’s where it all started ...

Thanks you! I have been reading for an hour or so and am on page 17. haha Only 340 or so pages to go!

[Wolfgang92025]

Irving,

My build is 1/4" outside, 3/4" foam and 1/8 inside.
If I was to do it again, I would go 1/8" in and outside. Still plenty strong.

Excellent. Thanks a lot for that. I'm not sure I can get 4 x 8 sheets of 1/8" locally. But may do 7/32" all around..

What did you use for framing? Cut up lengths of 3/4" ply?

1/2" poplar or 3/4" oak were it could be seen, around the doorway.

[razzer]

That's interesting to hear about the 3/4" foam core Wolfgang , I had thought you would need thicker foam to make the stress skin construction strong enough . Very good to know . Sigh ... I guess I need to wade through that super long thread . Of course what I had read already was interesting and enjoyable . I just wanted to get to the planning stage before Fall .

[Irving]

That's interesting to hear about the 3/4" foam core Wolfgang , I had thought you would need thicker foam to make the stress skin construction strong enough . Very good to know . Sigh ... I guess I need to wade through that super long thread . Of course what I had read already was interesting and enjoyable . I just wanted to get to the planning stage before Fall .

I'm making my way through it now. I have a hard time imagining that I will make it the whole way through.. haha But we'll see. It's definitely been worth it so far. Been learning a lot about canvas/tightbond 2 coatings as a finish (though I may use tightbond 3). Also using 75% thinner with 25% polyurethane as a sealer is a solid idea. I agree with the ideas of using this sealer underneath the trailer because it really soaks into the wood rather than just being on the surface of the wood.

[razzer]

Yeah Irving I'm only up to page 32 so far . I mean I'm building a camper to pull behind my bicycle that's small so I shouldn't need to read the whole thing , right ?

[S. Heisley]

Mine is 1/8" outside, 3/4 " foam, and 1/8" inside, with a mostly 1x2" poplar board skeletal structure and lots of epoxy. I think that's one of the old traditional plywood building methods

The "Foamie" building method is only a couple years into its building history. I think people are using the thicker foam because it is sturdier and can stand on its own, needing less wood. The 3/4" foam needs more wood and is therefore heavier than most "Foamies". Each method has advantages.

A basic piece of 4x8 'x 1/8" plywood weighs about 9 lbs. (+or-, depending on how it is made)
A basic piece of 4x8' x 3/4" Styrofoam weighs about 1.5 lbs. (You can extrapolate some from there....)

If you are going to use the old traditional methods of building, (plywood/frame & Styrofoam/plywood), just read through the Generic Benroy Plans in the pull-down menu under Design Resources, at the top of the screen and you'll have a pretty good idea of what to do.

If you are going to build a "Foamie", you might be able to read a few Foamie build threads and get "enough"; but, you might also want to read the big thread, just to be certain. Maybe, once the Styrofoam dust settles, someone will build a set of Generic Foamie Plans. ...Dunno....

[GPW]

Keep reading !!! It gets better !!! Admittedly , there’s a bit of excess babbling (I blame myself! ) and pet pictures .... But it’s the Evolution of the Foamie ... How it got started , How to use it , and how to stay away from Bears and frozen turkeys ... and lots more ...

There are major differences between Foamie trailers using mostly foam , and wooden trailers using foam for insulation only ...

Generic Foamie plans .... Anybody looking for ideas , please check out my Gallery , lots of ideas there... Just press the little camera button next to the PM button under the picture of my Lego trailer on the extreme left side of this post ...

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[bonnie]

BUB's lower walls are 1" foam with 2 layers of fiberglass. They aren't going anywhere. I am rebuilding the top to suit my non-traditional pop up design. The top will need more bracing, so there will be a minimal wood frame. I am leaning toward 1.5" wall thickness to give me a bit more stiffness to the foam parts. The BUB's original roof will also be re-purposed.

[Irving]

I have admittedly only read 25 or so pages into the big thread, but I don't understand why some of you have settled on tightbond 2. Tightbond 2 is advertised as being "water resistant" while tightbond 3 is advertised as being "waterproof". It may cost a few dollars more, but it seems like it would be the better choice based upon that alone. Or is there some other reason why tightbond 2 was the glue of choice for some of you?

[Irving]

Based upon advice I have read in the "big thread", this is what I have planned as a finish for my thin plywood exterior that will cover 1.5" foam.

- layer of watered down tightbond 2 or 3 with drop cloth canvas covering the whole trailer
- watered down tightbond 2 or 3 rolled over the canvas. 1 or 2 coats until fully saturated.
- sprayed with 75% thinner 25% polyurethane through HVLP gun. several coats.
- exterior primer. 2 coats
- exterior house paint. 2 coats.

Any feedback, advice or opinions that anyone has on my finishing plan would be awesome.

[GPW]

Irv, keep reading ...

[Irving]

Irv, keep reading ...

Dude. It's 360 pages. haha

[GPW]

I know, I know .... a good bit of the discussion was me trying to convince the naysayers that it would work ... some materials testing , and some pet pictures ... Lots to learn !!