Has anyone used foamular 250 over 150?

[GPW]

You may think this odd , but those cross braces on the trailer can support the floor in many places , and it’s pretty easy to add extra ( wood) ones when you need it ... You don’t need a floor you can dance on , unless that’s what it was intended for ...

[seanc]

Commercially available SIPS often come with 7/16" OSB on both sides and weigh 120 lb. That's total overkill for a SuperXL foamie tiny house.

I can't help but think "build your own, build your own! It will be fun, come on!"

Special foam sizes are often only available if you order a full pallet.

A full pallet of 3" Foamular 250 contains 32 sheet at $48 a pop. That's enough to build the 8' x 16' Boulder tiny house I referenced early, with quite a few panels left over for initial experimentation/mistakes.

What if you glued your own SIPs with 1/4" Ply on the interior then wrapped the entire exterior in canvas after assembling the panels together?

Is a properly adhered canvas skin over 250 weight foam less durable than any typical tiny house exterior cladding (T1-11, board and batten, reclaimed tin, galvalum, vinyl)? I think my foamie has 20,000 miles at this point, it looks fresh as a daisy and I have more and more confidence in it every day. How many tiny houses have 20,000 miles?

Sorry for rambling, It's hard not to have these thought experiments since I go to sleep every night staring at my foamie walls and ceiling

[rruff]

Is a properly adhered canvas skin over 250 weight foam less durable than any typical tiny house exterior cladding (T1-11, board and batten, reclaimed tin, galvalum, vinyl)? I think my foamie has 20,000 miles at this point, it looks fresh as a daisy and I have more and more confidence in it every day.

GPW linked a place awhile back that makes light SIPS with thins phenolic/fiberglass skins. DuraSip. They will also sell the skins alone, but you'd probably be better off just buying the panels already made. Fiberglass the joints and paint it, and you should have a great shell. http://www.durasip.com/

[GPW]

Every year is a milestone for the Durability of just plain canvas covered foam … and if there is any hard covering material considered, my own experience with common chipboard over foam proves it superior to plywood (JMHO) … and all this is easily repairable , but you know what …. we Never needed to repair it … turns out canvas coverings ( even thin canvas) over foam is really tough stuff … Just ask anybody here who’s already built one …

RE: Durasips … my buddy is working on building a kayak from that material , still in the planning stages (CNC template making) … wish we had more to report …

Ruff, Their sips are tempting and I think they’ll even cut it like you want , so it becomes just a matter of basic assembly for you … I could easily see something like a Weekender made of just their sips … with all the parts pre cut , but I guess unless you supplied the EXACT cutting dimensions , there would be more programming time ($) … a Kit would be Nice …
I wonder how extensive their cutting service really is … and what they would charge for a “flat pack” Trailer parts kit … shipped to my house … or just the sides ? ( and door)

[GPW]

Went to my buddy’s shop today , saw his scale model of the boat made for the durasip material … he’s got the parts worked out and is ready to CNC the big templates …

And he said if anybody is interested , he'd be glad to share the CNC files with them ...

[seanc]

Wow! those durasips look perfect.

i'm really curious what a rough price estimate would be for, say, a 3" x 4' x 8" panel? $100, $200, 300? If you were making your own out of 1/8" ply skins and 2" XPS it seems like raw material alone would run over $100. Definitely keep us updated on your friends kayak.

A few months ago I was parallel parking my camper and backed into a telephone pole My camper is almost 9' tall, so leans well over the curb on streets that slope towards the sidewalk, which most do.

The entire truck bounced. The paint was chipped and cracked around the top right corner of the camper (about 2" x 4"), and the foam wbut over the course of a few days the foam sprang back into shape. Just one more event to give me confidence in the foam and canvas!

[GPW]

“ but over the course of a few days the foam sprang back into shape. “ … That was always like a Bonus …. a most pleasant surprise..

[rruff]

i'm really curious what a rough price estimate would be for, say, a 3" x 4' x 8" panel? $100, $200, 300? If you were making your own out of 1/8" ply skins and 2" XPS it seems like raw material alone would run over $100.

I didn't price full panels but I think the skins were a little over $1 a sq ft. Shipping is pretty high also. It isn't bad compared to 1/8 marine ply, at least for me since I'd have to have that shipped too. If your Home Depot carries 2.7mm luan, that stuff is only ~$10/sheet, though. The cool thing about Durasip skins is that you get continuous rolls so no seams on large panels. They will custom size built panels also.

over the course of a few days the foam sprang back into shape. Just one more event to give me confidence in the foam and canvas!

Yes, that's one of its outstanding features. The PMF will give a bit and the foam cells will compress and then recover if they aren't crushed too much. Hard to beat PMF over XPS for light, cheap, insulated, water tolerant, and tough enough.

I had decided to go with fiberglass after demonstrating that it was much stronger, stiffer, and resistant to penetration and dents. Thing with fiberglass though if you push it too far it breaks. And the soft foam isn't the ideal substrate for a thin FG skin. For instance you can put a dent in your PMF-foam camper by pressing on it with your knuckle, but it will slowly heal itself. FG-foam will take a much bigger hit before it is phased (bigger even than what would permanently dent the PMF), but then it will be cracked. Ideally I'd like to get heavier duty foam to better support the skins, but the price of shipping that stuff is insane.

BTW, I was playing with some pieces of 15 psi (Foamular 150) and 25 psi (Certifoam 25) yesterday, and they did behave differently. The 15 was a little less stiff as expected, but it would also bend farther before it snapped.

The reason I was wondering about it was because I noticed a different failure mode in testing. I'd built some samples of each using 1" foam and FG skins, ~7" x 36". I supported them on the ends and then kung fu stomped them to make them break. The 15 psi samples failed by a crease forming in the upper FG skin (the one under compression) and the foam under this spot compressing, until the FG eventually snapped (cracked but intact). The 25 psi sample was completely different. The foam actually sheared apart! The skins were in separate pieces. The 25psi sample had heavier skins, which may have contributed to this, plus it was a different brand of foam so maybe has different properties than Foamular 250. Wish I had time to do real scientific testing on this stuff!

Anyway, I don't think this has any bearing on PMF-foam composites, but thought I'd mention it.

[rruff]

And he said if anybody is interested , he'd be glad to share the CNC files with them ...

[rruff]

Ultimately I would like to build a 4' x 8' vacuum press from the plans available here http://www.joewoodworker.com/veneering/welcome.htm and glue up entire panels.

You don't actually need a press, although they are ideal if you are making a lot of panels. Saves needing to pile a bunch of weights on to keep it flat.

I glued 2.7mm luan skins to 150 foam (textured with a carpet seam roller), with PLP (troweled on). Glue joints were way stronger than the foam. Very strong and stiff panel. I haven't destroyed that one yet.

[seanc]

Rruff - how much plp ( I assume that's loctite PL premium) did you trowel on per side? A whole 10oz tube? Why PLp over t2? Are there big differences in adhesion/ease/set time/cost when flying to xps? I'm sure this has been answered in great detail somewhere...

If I were to build another camper I would want the inner skin of the cabover walls to support the cabover without the need for an additional cantilevered beam Running the length of the cabover. Are you planning something similar? Do you think 1/8 ply on the inside and PMF on the outside has the shear strength to do that?

[rruff]

The foam was heavily textured and I used about .12lb/sq ft. Buy the 28oz tubes. One tube does about 15 sq ft. I think it sticks to foam way better than TB2 and is much stronger. Price works out pretty similar when you consider that half the TB2 evaporates. I'd use PLP or epoxy.

With a sandwich structure, the skins don't work independently. I built a camper a long time ago and didn't use any beams for the cabover. It was all 2.7mm luan skins on 3/4 foam, and 1x2s spaced every foot or two. This go around I'm planning to use minimal stringers, FG skins, and 1 and 2" foam. Not sure if PMF is good for that, if the sustained load is too high it will creep and sag.

[GPW]

“ Hard to beat PMF over XPS for light, cheap, insulated, water tolerant, and tough enough.” …. Ruff , this worked out waay better than we ever expected , but then again , the old time trailer builders used it very successfully ( canoes too) … with the old "Aluminum paint” on it … that must have been tough eh ? We remember from years past , pontoon pedal boats in our local City Park lagoons , plywood hulls covered with well painted canvas , they were there for many many years. ( see pic)

[rowerwet]

Went to my buddy’s shop today , saw his scale model of the boat made for the durasip material … he’s got the parts worked out and is ready to CNC the big templates …

And he said if anybody is interested , he'd be glad to share the CNC files with them ...

I'm very interested in this , how thick is the foam, and why the expensive covering?
There is a builder in Florida who createsfoam kayaks like mine, only he uses two layers of glass and epoxy over EPS.
He also claimed a $100 cost per boat, until finally agreeing that the amount of glass and epoxy brought it to $200.
Regular old PMF on XPS is about $125 for my boats.

[GPW]

What Foam ??? just skins …