I'll toss my 2c in on the exterior butt joint tape. I ommitted it for two reasons: First, I'm impatient, and with my schedule and working conditions it saved two days. Second, as this was my first boat, I didn't have a lot of comfort with being able to feather the area out nicely. Avoiding the color banding was a distant third, because I had already chosen this course.

It works great. You want to be a little careful with the panels before they're stitched up, but you'll probably be careful enough anyway. They're pretty tough. The feathering question was a poor thought in retrospect. On the Osprey, the deck glass is of two pieces, which also overlap right at the joint, so I still had feathering to deal with. It's mostly because of my lack of patience and experience, but I still didn't get that area faired quite as well as I'd like. Sanding into the glass just spooked me. Next time around, I think I'll spring the extra $20 or so to have a single piece of deck glass. That'll make one piece for the inside, too. Just for ease, I'm thinking that's money well spent. The Tern 14 glassing may not have that issue, though.

Have fun with the build, and the boat.