Holmes,

I keep my saber saw's sole flat to the deck when cutting a (non-recessed) cockpit opening, and t' heck with being plumb. In fact, it works to my advantage, far as I'm concerned. Kinda like the bevels we see welders grinding on mating pieces prior to letting the sparks fly.

I find, after four successfully executed coamings such as you describe, that the hot glue holds the riser strips to the deck just fine, despite the angle, especially in concert with the wood glue bonding each to its neighbor. Then when complete, the "bevel" is wide open (3/16" at best/worst?) for a great little fillet of dookie-schmutz encircling the whole riser, connecting it to the deck. I just lay the fillet right over any little blobs of hot glue.

Cheers, Kurt