semi-rigid plastic sheeting

[AllDownhillFromHere]

Thanks Malto, I did play around with putting the bear can at the bottom of the pack, so that the heavier things weren't at the top/outer half to pull the pack away, but the rigidity of the bear can made it feel weird. I'll take another look at the layering. Thanks again guys, I did look into that corrugated plastic but it's too creas-y, if you flex it, it wants to bend, plywood has a nice springness to it, as low-tech as it is. There's only going to be some sections where I need the 45lb a capacity (looking at you, Sierra, and drier desert sections), so I might be able to reach a compromise and then power through.

[Dogwood]

I thought this was for the PCT. Can't you balance out water wt in the Mojave with a lighter wt kit? There's a misconception that HUGE water hauls are an absolute necessity in the Mojave. That doesn't have to be an absolute. HYOH.

[Kaptainkriz]

Cut up a plastic toboggan/sled?

[AllDownhillFromHere]

Cut up a plastic toboggan/sled?

Thats genius - just about the flexibility/rigidity I'm looking for! Now to weigh it.

[Kaptainkriz]

Post pictures when you come up with something!

Thats genius - just about the flexibility/rigidity I'm looking for! Now to weigh it.

[AllDownhillFromHere]

First attempt at the plywood - compared to the foam pad that it's replacing.

[Secondmouse]

your frame (or frame sheet) really only needs to transfer the weight from where it is suspended at the top of the pack to a point where it can be supported by the waist belt. in theory you could do this with just a single 1" aluminum stay but attaching it to a sheet works so much better for stability and structure.

you can buy pieces of strap aluminum in Lowe's or Home Depot that can be cut on site or at home with a hack saw and can be bent for a custom fit. attaching it to a sturdy flexible plastic sheet could be done with Gorilla Glue or stitching a pocket made of webbing onto the sheet. I actually did both because I'm not the trusting kind. and duct tape won't last - trust me, I tried...

[blw2]

you might some materials through one of these sources
http://www.usplastic.com/?gclid=Cj0K...z7MaAjLD8P8HAQ
or
http://www.harringtonplastics.com/
or
https://www.mcmaster.com/

or maybe something on amazon or ebay too.....

I have some cutting boards from ikea that seem to be made out of a similar plastic to the tobagan idea. Maybe not big enough though, but that seems like it could work.... I just checked, they are PE-LD (low density polyethylene). Maybe 1/8 thick. these particular things might be a bit too floppy though if you're going for something more like the plywood. maybe a HDPE which I believe might be stiffer.

[Arc-Niner]

I recently spoke with a tech from US Plastic about this very issue (I'm working on a DIY backpack), and she recommended either their high impact styrene sheet (which is supposed to be stiffer than HDPE at the same weight), or using 3/8" nylatron GS rod stock. I have yet to try either one, but those are likely to be my next experiments.

[AllDownhillFromHere]

I was thinking about trying the lid from one of those big rubbermaid tubs, cut to fit. Either that, or swap the pack for one with a frame and be done with it. Rolling my own, I may end up with similar weight, but still a suboptimal almost-frameless pack.