Steve & John, thanks for your assessment of composite board.
I gave a lot of thought to the strength of the stanchions, but bulwarks were an afterthought.
My knowledge of wood is limited and your suggestion to consider plain sawed Ash is appreciated.
I will probably never test the actual strength of the brackets. Fortunately, I started their construction after I had gained some experience in working with the materials.
The fillets used for G10 joints are covered by 2 layers of 1708 biaxail in a chemical bond, for a total of 4 layers 1708 (top and bottom).
Over a width of 4", I expect the tensile strength to be substantial.
Top Joint:
Bottom Joint:
For the quantity of epoxy that I have used over the past several years, West Systems is too expensive.
I purchase from Clark Craft for about $72/gal. I've had good results with their product which has no amine blush and a 1 to 1 mix ratio.
Their mix ratio makes it easy to make batches as small as 10 ml, using 1oz mixing cups.
Yesterday was a full day of working to prepare backing plates for the brackets. The underside of the deck near the edges is generally uneven.
Most of the backings require epoxying the plate in place to spread the load evenly.