Well I see why CLC prefers scarfs to butt joints. I’m trying to align the panels for my outriggers, and I’m having a devil of a time doing it. I used fiberglass butt joints, where you butt the panels together and use layers of fiberglass tape to bound the two panels together. I wound up with a really stiff joint but that’s the problem, they’re too stiff. That’s why I couldn’t get the panels to torture correctly. Even when I reduced the beam of the bulkheads for the floats, the panels wouldn’t take the shape. The cross section would be terrific at the bulkheads. But the minute it came across a butt joint, it would flatten right out. That’s why that shear clamp scarf blew out, the butt joint is stronger than the shear scarf!

I used three layers of glass at each but joint. 2in 4in and 6in wide tape, so it’s feathered out. The end thickness is a great as the plywood.

OK give up on torturing the panels and go for a simple Vee shape. Well I’ve still got a problem. I followed standard practice and staggered the butt joints so joint they wouldn’t align on purpose

Port float
4 ft, 8 ft, 8 ft port panel
8 ft, 8 ft, 4 ft starboard panel

Starboard float
8 ft, 8 ft, 4 ft port panel
4 ft, 8 ft, 8 ft starboard panel

But the butt joints are flattening the panels out, and since the joints are staggered, the centerlines of the hulls are weaving back and forth like a snake! It’s not much 2 degrees, but over 20ft it really shows up.

I could jig the deck to force it to shape, but it will just pop back after it’s removed from the jig.

I could pull the panels apart, and stitch them together so the scarfs are aligned

Port float
4 ft, 8 ft, 8 ft port panel
4 ft, 8 ft, 8 ft starboard panel

Starboard float
8 ft, 8 ft, 4 ft port panel
8 ft, 8 ft, 4 ft starboard panel

This should result in symmetric hulls, but there’s no way they will match each other. On the other hand I’m only going to have one hull in the water a a time. But now, I have to figure out how much aligning the scarfs is going to weaken the structure, and then calculate what I need to add structurally ( read more weight ) to make up for it.

Thoughts?