Big Night

Tonight was big. There will be more "big" nights but this was one of them. 

I started by working some more on the routing jig. Last night I watched a few videos on scarfing and decided that routing should work. After fiddling with it for another hour, I settled on giving it a try.

After supper I went to the garage and pulled out all the planking plywood, 6 sheets - 4 meranti and 2 okoume. I'm using meranti to try to save a few bucks (about $100), but felt I needed okoume for plank #1 which has the most bend in it. Since plank #3 is made from the same piece, it will also be okoume; but the hull will be painted so no big deal. Meranti is a little heavier but it won't really factor significantly into my boat. 

Clint designed the CIY 16 so that the planks are cut from 24" wide plywood. That's really convenient. So I cut the six pieces down the middle. I used the skill saw and a 1x4 as a guide. I'm cutting on the pallet.

Here are the pieces after cutting. Once scarfed, they'll be 24" x 16'!

Here are some pictures of the scarfing jig in action. It's kind of hard to make out various pieces, but I cut two triangles with a 14:2 rise (to give me a 7:1 scarf). There are two boards running between the tris with a gap just big enough to give me 2,1/2" of leeway, which is enough wiggle room for my scarf joint, with the router. Then there is a board running crosswise that the ply will sit upon and butt up against the lower board. 

Here is my sketch of the jig. I made a couple changes when I built it. It's 27" wide and the board across the bottom that the plywood sits on is butted up against the lower guide board. I did that to give me a "stop" for the plywood and to bring it into closer proximity to the router bit.

The jig is attached to the strongback with two screws and a board clamped down on the strongback.

In this picture you can see I've run across the ply with two passes. The dark board is just sitting there. I made 4 of those of widths varying by about 7/16", each one for a different pass. My bit is 1/2". The lighter board that is nailed down is my guide.

In this pic you can see a couple of the removable boards.

Here you can see two spacers which give me room to run the router all the was across the ply. The jig is 27" across. The ply 24".

Here is a picture of the other side of the jig with more spacers and a wedge to keep it tight laterally when routing. 

And then I wedged my practice scarf between the ply and the top router guide board. All of this was to keep the ply from moving. There are a lot of forces working on that ply when routing.

Here is a final scarf joint. 

I did two. The first I had the same trouble I had on the trials. The slight edge I was leaving (about 1/16") was getting ripped out by the router. On the second piece, I made the first pass twice. The first time with the router set not quite as deep. The second pass all the way down. It seemed to work better. The edge is "feathered" but that's ok. The epoxy will fill that. The slope is even. I'm excited!!!

Here are the first two pieces waiting to be glued together.