Saturday, June 25, 2011

Sheer Strake

Well, here we are.  The fourth and final strake, at the boat's sheer, is on.  No problems or big insights to report, I got better at it as time went on.  I still need to trim, add more filleting compound at the seams, and recess the nails before I start finishing the bottom.  On the bow photo you can (barely) see the bow piece protruding a little on the top side (bottom in the photo since the boat is being built upside-down).  That protrusion is there in case I decide to rig the boat as a sloop: the bowsprit will be secured to it with a pin.

The second photo shows the transom.  The last strake has not been trimmed yet, nor has the curve been cut into the transom itself.  All in good time.

After putting on the final strake, I cleaned up the garage (it was a total mess) and made room for the car which had been banished outside.  The next two weeks I will be busy with other things, so there won't be any progress or updates. 

But sometime in July and early August the bottom (keel, skeg, paint and all) will hopefully be done, and it will be time to flip the boat right side up to work on the top and insides.

So don't stop checking 176inches!


Saturday, June 18, 2011

Strake 3

Progress has been slow, because of a backlog of gardening and home improvement projects.  For example, last summer I replaced my porch floor, cut off the rotten bottoms of the posts holding up the porch roof and replaced them with pressure-treated wood, and installed stair rails.  Of course the pressure-treated wood had to weather for many months, so I ended up puttying, sanding, priming and painting everything this summer.  I managed to do it (took four days) just before the dry weather ended.
Anyway, I had to put in seat stringers before putting on the third strake, which meant I had to notch five of the frames.  While trying the stringers on, the scarf joints broke apart, so I had to redo them with a shallower angle.  After putting them on (picture), one of them broke again (I neglected to put a screw in the frame nearest to the joint).  Clearly the stresses on these bent stringers are heavy.

Finally I put on strake 3.  The hardest thing about lapstrake construction may be shaping the strakes so they meet at the bow exactly right.  Normally this involves planing a rabbet in both strakes.  My rabbet plane was not working properly, however, so I ended up planing and sanding a scarf instead.  It worked out fine.

One lesson that I learned, though, was that it's very nice to have a helper.  When putting on the port strake, I did it all by myself and it was slightly off, which meant that the lapped edges did not line up properly, and I had to (slightly) force them together using screws and pieces of scrap plywood.  Once the epoxy cures I'll be able to remove them. The starboard strake went on much more easily, because I enlisted my wife's help for about 5 minutes to hold one end of the strake straight.  

The fourth and final strake is ready to go on, after the epoxy cures, strake 3 is beveled with plane and sander, and the tips of the frames are notched for the inwales.  After that, it will be time to put on the skeg and keel, and finish the bottom (set the nails, putty, sand, epoxy and paint).  Then I'll need to get some friends to help me flip the boat right side up to finish the inside.  With some luck I'll be done before the cold weather sets in.


Tuesday, June 7, 2011

Adventures with lapstrakes

Since last time I cut and scarfed all the rest of the long pieces: strakes 2, 3 and 4.  It involved measuring, drawing and cutting two copies each of two parts (fore and aft) of three strakes, or twelve in total.  The design program provided coordinates, which I manipulated on Excel.  When the time came to scarf and glue, I had to be extra careful not to join anything the wrong way.  I found that laying the pieces on top of each other, staggered in 2-inch steps, then using a belt sander, worked very well.  Provided, that is, that the sanding belt was coarse and very new--it's amazing how quickly the grit gets dull while scarfing.

I first beveled the edges of the garboards (strake 1 or bottom piece) to the correct angle. then nailed and glued strake 2, lapped over the beveled edge of the previous one.  Nailing along the lapped edge is a lot easier with something heavy, smooth and hard held behind it--a second person would have been good doing that but I don't have a helper, so I tap in the nails enough for them to stand up, then hold the clenching iron against the back and nail them in.  I have been filling the excess overlap gap with filleting compound (epoxy and wood four).  Here's what the boat looks like with the second strake on.  There is still trimming, sanding and nail setting/puttying to do, but that can wait.

After scarfing what I thought was strake 3, I tried it on for size, but it didn't fit.  Panicked, I concluded that I had glued the fore and aft pieces upside down--the curve of the edges looked that way.  I looked for ways to cut through the scarf, but it was clearly too strong: I would have to cut the long pieces in half and butt-join them the right way.  Before taking that drastic step, I tried to calm down and double-check.  Using the Pythagorean theorem again, I calculated what the width was supposed to be at different positions and measured the pieces.

As it turns out, the pieces I had scarfed together were strake 4, the last, top strake (at the sheer).  The pieces of strake 3 were still leaning against the wall, unscarfed.  Why I never actually labeled them and relied instead on a vague idea (strake 3 in this corner, strake 4 in that one) I cannot explain to my satisfaction, but I made a mental note for next time (and so should you).  Strakes 3 and 4 were too similar.  I had labeled fore and aft, top and bottom, but not 3 and 4.  I expect it's even easier to mess up with traditional, narrow lapstrakes, as opposed to the 4-per-side wide ones I used.

So there you have it.  Strake 3 fore and aft halves are glued together and curing as I write, and will go on next.

Until then, keep checking 176inches.