I have been thinking more about my meeting with Roger Hatfield. One take-away that stands out is that despite an increasingly competitive market, he is sticking with epoxy resin. I have seen many builders switch to vinylester or even (I can’t believe this, but it happens) polyester. Roger told me that it makes life on the shop floor so much simpler. As I have said before, “you can be almost brain-dead and get epoxy right.” Recall that to get good strength numbers, the catalyst and initiator ratios must not only be very accurate, but must change with every temperature change. I expect that when Roger tests laminate samples, he gets consistently high numbers, unlike the ester builders, I am guessing. Maybe that is why designers who favor polyester also dislike sample testing.