The Astroliner

[Atomic77]

Hi Oleg and thank you! The Celotex I referred to is a rigid foam board that comes in 4x8 sheets. It has a foil backing on each side. It looks like this:
http://www.menards.com/main/mobile/sear ... tpt=mobile
I bonded it to the plywood with epoxy then sandwiched it between the plywood and the frame. So, foam board down, plywood up. I hope this answers your questions!
Michael

[OP827]

Hi Oleg and thank you! The Celotex I referred to is a rigid foam board that comes in 4x8 sheets. It has a foil backing on each side. It looks like this:
http://www.menards.com/main/mobile/sear ... tpt=mobile
I bonded it to the plywood with epoxy then sandwiched it between the plywood and the frame. So, foam board down, plywood up. I hope this answers your questions!
Michael

Thanks Michael, that is very interesting, because it may affect(change? ) my design now.

I also have 5/8' plywood floor epoxied together with West System and was going to cut my 1-1/2" XPS rigid foam (Owens Corning Foamular 300, i.e. 30psi ultimate compression strength, yield strength is accordingly lower) in rectangles and epoxy them under the plywood in between the steel members, BUT I like your approach better, it is cleaner, must be more rigid and soundproof, simplier to build and better insulation properties overall . I just wanted to confirm that this Celotex foam will not yeild or crash between the trailer floor and steel frame members pressure points I have on my trailer frame. My trailer frame is taken from 1980 Coleman Iroquois, Canadian version of the Brandywine tent trailer. The original frame is 10-8' long, my trailer will be mostly foam with fibreglass sandwich, foldable and about 13m long, targeting at minimum weight and aerodynamic drag. From the plywood floor and up it will be like a boat or aeroplane structures .

Do you know what is the compression strength (ultimate and yield) of this foam in psi?
I would just go with this Celotex you used.

[Atomic77]

I'm sorry, I do not know the compression strength. But what I do know is the weight of the 5/8" plywood spread out over the foam board took quite a bit to compress it when I bolted it down. I tightened my bolts until the foam slightly compressed. And I completely covered the underneath side of the trailer and the foam board with truck bed liner. Everything seems tight, waterproof, quiet and I really like it.

[OP827]

According to this link http://c.ymcdn.com/sites/www.polyiso.org/resource/resmgr/technical_bulletins/tb102_jun30.pdf Polyiso rigid foam is 16-25psi strength (looks similar to the one you installed), which is in the same ballpark with pink XPS foam I have, except you have foil that may slightly improve the compression properties. 1 inch wide strip of frame 36" long amounts to 36sq.in. x 16psi compression strength = 576 pound ultimate static load capacity... I'll have to run some numbers for my actual frame and go from there. Thanks for response

[Atomic77]

You're welcome!

[KCStudly]

I think the concern about the foam compressing over time is valid. I used small pieces of blocking at each bolt location to keep the fasteners from crushing my floor. Another option might be a thin layer of ply strip laminated to the bottom of the foam just where it will contact the trailer frame, then coat over that. The strips would spread the load a little more and provide a hard wear surface to prevent chaffing. $.02

[Atomic77]

I'm not concerned. The weight is spread out so much. It's the water bed vs. refrigerator theory. Good suggestions though.

[Mike46]

... I used West Systems with thickener on all the framing pieces for the glue, then sealed everything with West Epoxy. I also glassed all the seams to tie it all together...

Could you elaborate on your epoxy gluing and sealing. Sounds like all the surfaces of the panels were sealed, did you sand the joints before gluing one panel to another?

I'm wondering about sealing all my panels before assembly, if I use TB2 on the joints I would have to hold the sealing epoxy back from the joints. If I glued the joints with epoxy could I sand the sealed joints before adding epoxy with thickener to glue the joints together? I can't imagine getting it all sealed and assembled within the window for a chemical epoxy bond.

Thanks, Mike

[Atomic77]

I didn't do much sanding prior to gluing. I knocked down anything obvious but I don't like the surface to be smooth. West likes to be able to grab on. I was able to glue up one entire wall in two evenings. (Long evenings.) First I laid out the walls and the parameter framing. I traced around it so I knew where to glue. I planned the mix for two stages. I mixed epoxy and brushed it where I marked all the way around the wall. Then I mixed a second batch and thickened it with Aerosil. I buttered the joints and all the backsides of the framing pieces, hitting it with a staple as I went. When I was done I used a gloved finger and lots of paper towels to wipe my finger on and I smoothed away all the squeeze out. I let it kick overnight. The next day there was nothing to sand because I had smoothed away all the excess already. Again, I laid out the rest of the framing, traced all the pieces, brushed the areas with epoxy, buttered up the pieces with thick, and stapled them down. Again I fingered the squeeze out then I immediately mixed up more epoxy (thin) and rolled all the large areas and brushed all the nooks and cranys. I think I mixed two to three more small batches to get it done. I had a cup or two go off before I was done, but it took several hours for the rest of it to kick in my 60 degree garage. Hope this helps you!

[Atomic77]

I got a little more accomplished tonight. I got all the foam board cut and glued into place. Now I get to do it all over again on the other side!

[Mike46]

Thanks for the blow by blow, appreciate it.

[Atomic77]

I hope that answered your questions Mike.

[rebapuck]

Love the door. It's got personality.

[Atomic77]

Thanks Judy! And I love the VDubs. When I was a kid my Mom had a green 65 and Dad had a blue 66. Dad sold "Farm Fresh Eggs" out of his and Mom sold her paintings and other hand made items out of hers at local fairs and festivals. And they still swear they weren't Hippies...

[Atomic77]

We spent our Saturday building the right side wall. It took some time to figure out door and window placement but once we did, things seemed to go together pretty fast. It's nice to have a girlfriend who isn't afraid to get dirty!