I'm looking for rod/stay ideas to slide into a currogated plastic framesheet (i couldn't figure out how to keep the metal options discussed on these forums light enough) .
After looking at various materials on some sites-- http://www.kitebuilder.com/stock.htm and http://www.johnsonplastic.com/plastics.php --I'm confused. Anybody familiar with these materials?

This is for a Jam2 and the currogated plastic (sign material) works best with 1/8'' or 3/16'' rods.

Did you try thin wall brass tubing?

You can inject expanding foam into the hollow tubes of the sign material - it will come out the ends so tape that area up to protect it and then trim off the excess and remove tape when it dries. Don't do all the hollow tubes - try four on each edge and two in the mniddle to start with. It adds a little weight and stiffens the material. For the dame weigh I use a peice of 3/4 thick foam - like the Walmart foam pads. It weighs the same as the sign material and is used as a sit pad at camp. There is a pic of my jam on (somewhere) photobucket --- hootyhoo_bucket. I took the hydration sleeve out and sewed it on the outside like and added pad straps. I love it.

So you replace the foam in your Jam, or you added the Walmart foam to the existing foam? Just wondered, I was going to add the sign material to my Jam and Pinnacle. Sorry if this is a hijack.

I left the original foam in place - i took it out to use a pattern and put back. I have the sign material framsheet and a 3/4 foam. I use one or the other. When using the 3/4 I just put it in the pack first against the backpanel then load the pack - this is 90% of the time. It makes a great seat when in camp or can extend a short pad. I took the hydration sleeve out of mine and sewed it onto the outer pocket - you would be shocked at the amount of stuff that will fit in there. A I added pad straps - now it stands on its own. pic -- http://www.flickr.com/photos/13716428@N03/page2/