First, what is the sheer clamp? It’s the longitudinal piece to which the deck and topsides are clamped to make the hull-deck joint. As you might imagine, it’s position is at the sheer line of the boat. The finished dimension called for in the plan is 5/8 x 2-1/2 inches.
After laminating the chine, the sheer clamp is the next major structural piece that requires extensive bending and twisting to get the proper shape. If you missed the discussion about the chine, you can catch up here.
So being the clever guy I am, I thought I’d stack four 5/8 inch strips and make quick work of it. I milled my 5/8 strips, scarfed them together to get the length I needed (approx. 23-1/2 feet) and started bending them in to the notches in the frames. This approach resulted in utter failure as 5/8 inch fir is way too stiff to take the twist and bend required forward.
Back to the drawing board, and I found I would need 1/4 inch strips to get the flexibility I needed. Now, instead of 5 strips of wood, I would need 20 to make up one sheer clamp. That adds a little complexity to the glue up.
I made up some U-shaped brackets out of plywood to hold the strips in place once the glue was applied, then loosely bound them together with 3 wire ties and lifted them into place and clamped them. I was able to do the entire operation by myself which is handy since I’m working alone during our COVID-19 pandemic.
You can see from the pictures I used nearly every clamp in the shop to laminate each sheer clamp. Also, I was careful to tape each point of contact with the frames with packing tape so I could easily separate the laminated piece from the boat for fairing. Once I faired and filled it to get a smooth inboard surface, I coated it with 3 coats of epoxy to prepare it for permanent gluing into the frame notches.
The result was a beautiful, fair curve at the sheer. She’s starting to look like a real boat now!
Tim, that U bracket is a great idea! I only had 4 pieces to my laminated sheer clamp but getting them all lined up and bent to the frames before the epoxy set was like herding cats! I guess I could have used a slower hardener, I used the 205 fast stuff.
Thanks. It helps keep things in order for sure.
By the way, I prefer the 206 or even 209 hardeners. They give me more working time, and they’re easier on edge tool when cleaning up the work if you catch it the next day before it sets really hard. Less sharpening required of my handplane!
Hi Tim, I’m interested to know how you plan to plank the boat? I’m guessing from the observation that you haven’t cut rabbets, that you plan to use ply sheets with hardwood caps on the keel and stem, as described in the Gougeon brothers’ book.
Yep.
I think Gougeon bros. method is excellent. It’s what I was taught and I think it’s a superior method if done correctly. Too many people neglect to seal all surfaces of the wood and they end up with problems of trapped moisture. But if you do it right, it really gives great results!
Well Steve, it took me a while. But take a look at my latest post. There’s your answer.
Thanks for your feedback. I always enjoy hearing from you.