Friday, August 1, 2014

Gunwales in progress

Next up to install are the gunwales that stiffen the upper edge of the hull and provide a place to glue the deck to.  I looked around through my lumber stacks and found a couple 10 foot 1 x 8 pine boards that were relatively clear and I started ripping stock for the gunwales.  I had to work around a few knots, so I cut them out and rejoined the pieces with epoxy-glued scarf joints.  I cut them with the bandsaw and then finished them on the disk sander, which gave a nice surface with square faces, and all pieces the same.

I was concerned about the scarf joint's ability to stand up to the heat of steaming.  I read somewhere epoxy is good to about 180 degrees, and of course the steam is about 212 degrees.  I scarfed a test strip and steamed it and was able to bend it to the curve of the hull without failure, so I went ahead with the real stock. Here I'm again using lay-flat plastic tubing as my steam box, which lets me clamp the piece in place while the steam is still flowing.

CRAAACK!  Yep, scarf joint gave way.  <sigh>  The epoxy in the area of the scarf looks kind of grainy or crystalized - must be from the heat.  I broke the joint the rest of the way, and reglued it, then steamed the wood on either side of the joint separately and clamped it in place.  After the wood cooled, I removed the plastic and reclamped the gunwale and left it for a few days while I worked on other things.

Then I removed the gunwale and applied thickened epoxy and clamped it on.  I used a few 23-gauge pins through the gunwale and into the edges of the bulkheads to keep things from sliding around too much while I used most of my clamps to hold in in place.  I didn't need to clamp very hard, but needed a lot of them to pull the hull and the gunwale together all along the length.  I cleaned up the squeeze-out and left it to cure.

After removing the clamps, it looks pretty good.  There's a slight flatness in the area of the scarf joint, but it's not very noticable and I can probably improve on that after the deck is installed and I fair the edge of that.

The gunwale on the other side has two scarf joints, though, so we'll see how that goes.  

After the gunwales, I'll need to cut and install the carlins (which are the same size as the gunwales and run parallel to them about 4 inches inboard, to support the inner edge of the deck). I may rip the stock for the mast/boom/yard from my stock of sitka spruce and see if I have enough of that leftover to use for the carlins. If so, that is long enough to not need any scarf joints. 


  1. Very neat and clean work. Bravo.

  2. I did a double-take when I saw your first photo. "Hey, that looks like a Shopsmith 510. It is a Shopsmith 510!" I guess that makes at least two Welsford boats built using the Shopsmith. I like your setup for sanding the scarfs. Wish I'd thought of that. Beautiful work as always, Dave!

    1. Thanks, Joel. Yes, I saw you had a Shopsmith, too. I mostly leave it set up with the bandsaw on it and the disc sander, though I used the table saw to cut the long lengths of gunwale stock. I have a separate jointer, and I often use the bandsaw and the jointer in combination vs. setting up the table saw.

      Regarding the scarf setup, I had thought I could just run the stock into the disc along the temporary fence, but it worked much better to run it in as far as it would go, and then use the quill feed to push the disc into the wood.

      -- Dave