material question

[Chip]

Has anyone thought of trying to use honeycomb panels on the sides and top,,,they are lighter and stronger typically than plywood,,,well in some cases,,,what yall think,,is this an answer to lighter in tear construction,,,do a search on honeycomb panels or look at this link,,,(thinking again,),its scary aint it,,,http://www.ecomall.com/business/grid.htm cost is probably more but the weight savings may off set it,,I saw where a 4x10x3/4 recycle fiber panel is about 75 bucks,,,just wonder what kind of strength ya get on a vertical application such as on the sides,,,???ya'll smoke it over,,,what ya think,,,,

chip

[R Keller]

Chip, I'm blowing some smoke in your direction here:

This site: http://www.pixelwindow.com/gridcore/usergid.html states that 3/4"-thick Gridcore weighs 1.1 lbs./sq. ft. So a 4x10' by 3/4" Gridcore panel would weigh about 44 lbs. Compared to 3/4" plywood that would weigh about 90 lbs. for a 4x10' panel (about 2.2 lbs./sq. ft.). Or 60 lbs. for 1/2" plywood (about 1.5 lbs./ sq. ft.).

So yeah, some weight savings there. But a lot of other considerations/potential problems. Such as how do you attach the panels together and how do you cover the edges of the panels? What about strengthening areas that have need to have holes for lights, fender attachments, and other hardware?

And I don't think you're going to get any insulation advantages from the Gridcore compared to plywood (both are probably about equally bad!).

Assuming you're going to want something other than a Gridcore surface on the interior, if you add something like 1/8" ply or paneling (about 0.36 lbs./sdq. ft. or about 15 lbs. for a 4x10' sheet), you'll lose most of your weight advantages anyway.

Best bet to go really lightweight and insulated is probably to make foam and fiberglass composite panels. Think boat building. Or surfboards.

For the Road Toad, I ended up making my own composite insulated structural panels. 1/8" plywood (actually 5/32" since that was what I could get my hands on) sandwiched around Styrofoam and some poplar framing at the edges/attachment points. The panels ended up weighing about as much as 1/2" plywood (depending on how much poplar framing was used for each one), but are about 8 times as strong (bending strength increases with the cube of the thickness) and much more insulated. Of course, this method is very labor intensive.

Hope this helps.

By the way, this is not meant to disparage Gridcore. It looks like a really cool material and has been used in a lot of inventive ways.

Rik

[Chip]

Hey Rik,,,thanks for input,,,by the way the toad towed is looking real good!!!,On the honeycomb panels,,there are a ton of different manufacturers out there and the one I listed just happens to be first on the list,,,some others list and specialize in bulkheads and exterior walls for the boating and rv industry,,,usually a metal, wood, or filler such as resin would be used on the ends and in central points that need a mounting plate or increased strength,,the outside skins are available in just about any configuration,,paper, glass fiber, FRP, aluminum, plywood al the way up to marble for archectural applications,,I think if ya use something like this a lot lighter trailer could be built,,cost may go out the roof though,,but if all the engineering types on these web sites would get their collective heads together,,a sub 500 pounder (dry) could be a real possibility.
start with the frame,,a 4 to 6" thick foam panel with a "y" frame somewhat like the TAG except its laminated into the core,,sort of a uni-frame,,,and go up from there,,ya also get a little more "r" value due to the dead air space,,not a lot mind ya but some,,probably enough for most areas except in coldest climates,,,sure would make for some interesting construction details,,,just killing time till 5 pm so I can get back to work on my trailer,,yall keep em straight,,,

chip

[R Keller]

Chip,

Thanks for the further info.

I checked out things more and I guess you can also dado a groove at the end of the panels and insert a wood framing member.

It'd be cool to get panels with the aluminum sheet already laminated as the outside skin and a thin wood veneer on the inside.

I saw a photo on the website link that I provided that showed a table with "cut-aways" that exposed the honeycomb structure. That looked pretty cool.

I wonder how much insulation the dead air space provides. My guess is that they are large enough that you get mini-convection (micro-convection?) currents going that reduce efficiency dramatically. But that's only a guess.

Oh, and you just gave me an idea: maybe I'll call my trailer the "Towed Toad" (or Toad squared) instead of the "Road Toad".

Rik

[Chip]

hey Rik,,how bout "TOWEDr2) cant do a towed r square on computer but ya know what I mean,,lol
Oh by the way one of my contractors is getting interested in this and mentioned using a heavy paper covering over the honeycomb and then glassing the whole thing sort of like boats with a stich and glue const. method,,,,waalaa no frame work,,,we getting lighter,,,there gots to be a stopping point. thanks for the comments,,if ya find a reasonable source for the stuff let me know,,,I'm still thinking and I havent even got my first tear complete,,yall keep em straight

chip

[Chip]

Rik here is some more info on sides etc,,,,,http://www.panelteccorp.com/html/design.html

chip

[PcHistorian]

I've spent the last 1/2 hour trying to trace down this stuff.

Seems to me you could use the open air flow through the material for something like heating or cooling. Weight to strength is better than wood. Then say slip a dowel in to screw. Made of 100% recycled paper waste.