The screws were number 8's, and almost none of them stripped the threads in the hole. Where this did happen, I just rammed another one through both layers, right beside it. At the butt joints, I put them in four inches apart and got a nice tight joint each time. Butts were about a foot away from those in the first layer. I used a cordless drill to drive the screws.
Power is almost a necessity here due to the working time of the epoxy, especially in mid-summer.
I used 287 screws altogether, and it took a solid four hours, with no breaks, to do both sides, from the time the first batch of epoxy was mixed. I filled the joints at the edges right away, so that if any blush formed, it wouldn't be deep down in the joints where my sandpaper couldn't reach. The joints were already sealed with masking tape on the inside. Yes the mizzen is cut DEAD flat. It assumes some shape anyway, especially if the snotter isn't twanging tight, and more if the snotter is slackened.