Foam for bulkheads and shelving

[Johnny Swank]

I'm getting materials for a foamie together this week. This will be used primarily as a cargo/display trailer for my Tshirt business, but will likely use it for road trips as well. Planning on using 2" thick foam for walls and roof (will likely be using some spars for hard points if nothing else on roof as well), and would like to keep things simple and use the 2" foam for a rear bulkhead and simple shelves. Anyone done this yet? Could I get away with a mix of 3/4" shelves? Planning on using canvas/paint with some T2 and fiberglass strips thrown in on all stress points. Design will be a typical Benroy.

Using my 4x8 trailer that's been gathering dust for awhile. Likely upgrading the wheels to 13 or 14" depending on what hubs I can find.

Great resource here! Been lurking for a month

Thanks!
-Johnny Swank

[Wobbly Wheels]

Welcome Johnny !
I'm planning on doing both bulkheads and cabinet carcasses out of foam and epoxy/glass. The first thing I built was the door: sort of a proof-of-concept thing. The details (including deflection while weighted as a shelf) are in my build thread. If the shelves will bear much weight, be sure to allow for tension on the bottom and compression on the top as it tries to sag (or build in wood stringers)
I just picked up the materials yesterday to do the bulkheads in glass on one side and luan on the other.

[eaglesdare]

will your roof be curved? i used 1" kerfed for my curved roof. 2" would be way harder to get the tear shape, not impossible, just harder. i have had no troubles with my roof using the 1" stuff.

i have not made any shelves yet with foam, so can't really help there. i have however, made a 2" thick pause (dog agility) table, that my 75 ish lb dog jumps on, sits, and lays down on. no problems there yet either. it sits only on a 1" pvc tubing frame. i need to get it outside here shortly though, it has turned into another clutter holding horizontal surface in my house. right now it is holding 1 gallon of tb glue, 1 gallon of primer, my weighted down backpack, and a bunch of other stuff. so i think your shelf idea will be fine. although i am not sure on the 3/4 inch stuff, that maybe too flimsy for a shelf.

if you are going to do spars, i would use wood. we thought about foam spars but they really seemed to be too flimsy. now the bulkhead part, if using 2" i don't see any reason that would not work. i have added a half a wall using (i think) 1 inch stuff and that so far has been fine. but this was not for support, just as a divider. for support i would use the 2" stuff.

now these are only my opinion, from my own personal experience.

welcome to the foamie section. and please don't forget to get lots of

[Johnny Swank]

I was planning on going with 2" for the roof and kerfing every inch where it curves, but if the 1" with spars would be tough enough, I'll probably go that route. I'm likely going to need to put in a few hard points near the ceiling anyway to hang cords and whatnot on, and that'd knock out two birds with one stone anyway.

[eaglesdare]

i can say my roof works for me. i have spars in, but haven't hung anything.

[KCStudly]

TPCE is incomplete, but I have been working with the 1-1/2 thk foam and I think it will be more than adequate for walls and ceiling. I'm planning on 5mm ply inner skin mostly for the look, but haven't gotten that far and my impression of just the foam walls so far is that the 1-1/2 would be pretty decent with just the canvas skins inside and out. I don't think you need to go up to 2 inch.

My bulkhead is a more traditional, 3/4 foam and stick built frame skinned in 5mm ply, so I can't really comment there.

With regard to the shelves, I'm thinking a little differently. I think if you keep the shelves relatively short from front to back (say, folded t-shirt length) and put a foam rib or arch like GPW's sketches out at or near the front edge of each shelf, wrap the whole unit in canvas (or even a couple of layers of bed sheet for more flex wrapping into the corners), then 3/4 foam would probably by just fine for holding up T-shirts. In fact, you could make the front vertical support along the front edge of the shelves so that they also form a raised lip (like a tee section) and thus help to keep the shirts from shifting off of the shelves in transit.

Let me qualify this by assuming that you have a variety of different styles that will need to be organized on multiple shelves and not just one big pile on a single shelf.

Put a bunch of canned food goods or cast iron cookware on 'em and all bets are off.

[atahoekid]

I have 2" of foam on my roof and I tried to bend the 2" to make the front curve but gave up and kerfed 2 - 1" pieces and glued them kerf side to kerf side. Lots of foam dust was created in the process but worked well and got a nice bend. In thinking back, I might have been able to kerf the 2" foam if I had cut wider kerfs. Just FYI.

I made my shelving and bulkheads from 1/2" ply so I couldn't tell you how well 2" foam works but I stayed away from it so I wouldn't take up too much storage space.

[GPW]

A good reinforced foam shelf should hold most of our stuff , save the 500# of Beer... and if it’s a long shelf , a divider or brace in the center should work ... in essence making two shorter, stronger shelves...
One trick if you’re using wood strip edges to reinforce the foam , find strips with a crown , put that crown facing up to pre-load the shelf ... easy , and it works ...