Dave,
I've had this roll for a while and I know I don’t have the label and without digging for the invoice I think it is Biaxial Fabrics stitch-bonded 18 oz cloth with a 3/4 oz. mat on the back. I first bought it to build the boat with before I decided to go carbon. The layup still has a little flex to it. Ok for a strap but not strong enough for a support for the weight of the boat.

Last night I took a X-mas paper tube and cut it in half length wise then slotted it to allow a curve to fit the form. I started to glass it on and it was deforming. Damn they do not make paper tubes like they use to. That trick use to work. So I pulled it off and gave up on that idea. I have to think about it today I have two ideas:
1. I could take a piece of scrap pressed wood cut out the brace shape plus 1/4 inch and use a few "balls" of bog to hold the brace in place, then cut it away when I'm done. I did that with the temp bulkheads inside the hull halves when they came off the frames. To remove the frame I have a “rope” saw I slip between the two to cut them apart then grind the bog down smooth.

2. Lay a strip or two of carbon fiber over the form and that will stiffen it up. Then I still have figure out a way to attach it to the frame. Work is slow today so I've got time to mull it over in my head.