Build-Thread (sort of) - Hybrid(?) FOAMIE

[pchast]

In a torsion box the 2x2 on the edges is fine if needed for any screw attachments. You certainly need blocking where holes are planned for bolting to the frame. 1/2 to 3/4 lumber is more than adequate for the internal grid. Thinner plywood has been used for the grid but its more difficult to adhere to the skins.

Wood itself bends easier 90deg. to the grain in it. So use flat sawn lumber on edge to have greater resistance to bending.


I would suggest that you make a couple 'boxes' about 6" by 2' with your preferred materials and try the different skins. Clamp them as required. Then cure them for a couple of days. Lay them over a pivot and jump on them or beat them with a sledge and tell us what you find.

[JDHIV]

In a torsion box the 2x2 on the edges is fine if needed for any screw attachments. You certainly need blocking where holes are planned for bolting to the frame. 1/2 to 3/4 lumber is more than adequate for the internal grid. Thinner plywood has been used for the grid but its more difficult to adhere to the skins.

Wood itself bends easier 90deg. to the grain in it. So use flat sawn lumber on edge to have greater resistance to bending.


I would suggest that you make a couple 'boxes' about 6" by 2' with your preferred materials and try the different skins. Clamp them as required. Then cure them for a couple of days. Lay them over a pivot and jump on them or beat them with a sledge and tell us what you find.

Thanks PChast!!!

I'm not sure what you mean by "blocking where holes are planned for bolting to the frame" ? and "1/2 to 3/4 lumber for the internal grid" ? I have a basic idea what blocking is but not how you are describing it...and I assume the "internal grid" is anything not in a 2x2 rectangle that I'd build at the outer part of the floor...........so, these would include any interior Xmember as well as any pieces that run front to back???? For an inner grid are you talking about using pieces of plywood, lets say 1/2" thick and cut to a 2" wide piece and placed such that the 2" dimension is vertical?......doesn't the foam I plan to place inside the framework provide enough support????

Thanks!
_John

[wagondude]

You want blocking for the bolts because the foam will compress as you tighten down the bolts. You want to avoid that compression. Otherwise, the bolts will never have enough tension on them to stay tight and your floor structure could fail around the bolts. You are basically building a monocoque structure. The strength comes from a full contact bond between all joined surfaces. Any place where the bond could fail (compressed foam at bolts) will eventually transmit that failure throughout the structure until the whole eventually fails.

[JDHIV]

Thanks Wagondude! So much to learn...never enough time! But always there is a way to make time!

[JDHIV]

Thanks ALL for A L L of the info you have provided and the time you spent educating me!!!

I'M DEVIATING FROM THE FOAMIE (OR EVEN HYBRIDIZATION OF IT).

========================I have decided to go the route like a couple of others on this forum did (i.e. OHBUGGER & PJO129) by using a large full-sized truck cap/canopy and building a sort of wooden analogous truck-bed underneath it and mounting that on top of the floor I glue/screw/bolt to the trailer. So, I think MUCH of what you all posted is still useful !? !!!!

But, I'm still going to build a good flooring that is cantilevered out beyond the current width of the trailer...

...My current plan (as per help from my father) is to attache a flooring of 7 2x4's as cross-members on my trailer...and topping that with 1/2" B/C-grade plywood and filling the "voids" under that with 1.5" sheets of foam. This will get a protection layer of either RV roof paint and/or spray on truck liner. Then, I'm likely to make a roughly 2' wall in the standard construction of a typical American Wall...a baseboard layer of 2x4 running around the base of 3 walls (2 sides + 1 front) and running 2x4 vertical 'studs' spaced ~20" or so on-center and then a top-board on that (all glued/screwed & L-bracket screwed together...........this top-rail of 2x4 (or 2x3?) will be what the truck cap rests on and is bolted to....Foam will fill the spaces between 'studs' and eventually skinned in either the foamie fashion of T2 glue and canvas +paint or plywood and the inner skin will be thin 1/8" Luan or something to cover up the foam.

I will likely paint all wood with the "magic mix" rather than using pressure treated.

I will make this campable to start and then work on refinements.

Thanks to OBUGGER & PJO129 for their pioneering (?) work on this design....My overall budget and time frame didn't let me make a true TD shape or foamie construction THIS time around....but SOMEday I will take what I have learned and will continue to learn here to do so!!!

SO, I am going to create a new thread in the appropriate area and provide a link here in case anyone will appreciate the continuity and continue to help me with the basics that will lead to the successful completion of this new style of TTT but is also useful for traditional TD's as well as foamies!

THANK YOU...........THANK YOU............THANK YOU A L L !!!!!!!

LOOK BELOW TO WHERE I'LL PASTE IN THE NEW THREAD....(can't do it till I end this one!)

_John

[JDHIV]

THE QUASI-CONTINUATION FOUND AT: viewtopic.php?f=50&t=57069&p=1032456#p1032456

Thanks! _John



ps: the rest of my build will continue there!

[GPW]

JD, how many threads do you need for the one trailer ??? Usually ONE is sufficient ...

[JDHIV]

JD, how many threads do you need for the one trailer ??? Usually ONE is sufficient ...

LOL

I ended the one that was more about the "foamie" (this one) but wanted anyone who reads it and wants to continue following what I did to be able to do so...I also realized that my new actually-going-to-happen (soon!) build is in a different categorie and figured a new thread in the right area would be appropriate even though there may be some overlap in the floor construction that could apply to both styles.

Thanks!!

_John