The first strip, oops!, I mean, "plank" got epoxied directly to the sheerclamp. After that they got epoxied to each other and the frames. I had designed a cheap alternative to three-way clamps, made from 1" plywood and a couple bits of all-thread, but the planking was going a lot faster than I'd anticipated, and... the clamps I'd designed didn't have enough throat to go over three or four planks. So, I used the dozen bar clamps that I have to clamp the planks together. This worked well enough until I got to 12"s of hull, then the bar clamps weren't big enough either.
What I needed was a way to clamp the planks close together between the frames. At the frames, it was a simple matter of clamping a block to the frame, and drawing the plank down with another clamp. Between the frames, I was having a hard time getting the planks to fit tightly.
Enter... "The high speed clamping setup".
I cut battens 3"s wide from some 1/2" plywood scraps, and covered them with polyethelene. Then I screwed them to the inside of the hull. This worked like a charm. I got a good tight fit between the frames.
All the planks are screwed to the frames and the battens until the epoxy sets, then the screws are removed. The holes are later filled with thickened epoxy using the "Ziplok bag syringe" technique.
Planks are butted together at the ends. I started trying to butt the ends at the frames, but immediately realized that this was taking way too much time. Instead, I made temporary butt blocks 4"x6", again from 1/2" plywood, covered with polyethelene. They are held to the plank below the butt seam with two screws, then two screws into the butt ends, and when the next course goes on above the butt, two more screws. This forces the butted planks to conform to the hull. Only a few such joints need another 4"x6" plate screwed on the outside.
The butts are staggered 2' apart +/-.
24" of hull, Mongo pauses for some refreshment.
Recent Email questions prompt some additional explanation.
From Todd Dunn:
"...Are you really planking it with strips of marine plywood? How thick are the strips you are using and how many layers of planking to your intend to put on?"
"I'm planking with 3/4" A/B Marine Fir, ripped to 1&1/4" wide, then routed with cove and bead edges. There will be one layer of plywood strips, and then one layer of 1708 biaxial cloth outside above the waterline and two layers of 1708 biax below the waterline. The interior will also have one layer of 1708 biax all over. The frames will be glassed with a biaxial tape, and will be totally encapsulated. All other interior plywood (BCX Fir) will be glassed with cloth about 8 to 10 oz.'s depending on what kind of good deal I can get when it comes time to do that glassing."
This nonsequitur is in answer to an Email.
"Another reason that I'm not worried about epoxy starvation between the planks is that to start a 'run' of planks, I set up 6 or 7 planks on sawhorses, bead edge up, right next to each other, and coat them with the epoxy mix. At the same time, one of the crew is coating the cove edges on the existing hull. Just pryor to putting the planks in place on the boat, any semidry places on the beads are recoated. Then the planks are installed."
Just forget about the Strippers, the Planking continues.
Copywrite © Alan "Maddog!" MacBride 1999
Most recent Revision 08/28/00