The second strake

Most of the work described below was done over the Memorial Day weekend.  This post is dedicated to all those who paid the ultimate price in service to our country.

 

Now that I’ve got the skeg installed, I can start working on the remaining strakes.  Tammie Norrie has eight pairs of strakes.  The garboards count as the first pair, so I’ve only got seven more pairs to go.  By contrast, Wee Lass has only six pairs of strakes.  More strakes means more work, but I think the greater number of strakes, which are also narrower than the ones on Wee Lass, gives the Tammie Norrie a more refined appearance.

The second strake will be glued to the stem, the outside edge of the garboard, and the transom.  All these mating surfaces are beveled.  I already cut the bevels on the stem when lining off the boat, so the bevels on the garboard and the transom remain.

I tackled the transom first.  The mylar pattern gave the location of each of the planks, but the plank locations were cut square to the transom.  I used a batten to determine the slope of the bevel.  When the batten touched the outside edge of the transom, I crawled around and measured the gap between the batten and the inside edge.

2016-05-29 Use a batten to determine the bevel on the transom
2016-05-29 Use a batten to determine the bevel on the transom

Transfer the distance to the outside edge, mark off, and start cutting the bevel.  Hand tools are your friend for this task.  Why?  See Rule #6.  After cleaning up the bevel, check for fit with a batten.  The goal is to have a nice flat surface for the strake to land on, and no gaps between the strake and the transom on either inside or outside surfaces.

2016-05-29 Transom beveled to accept the second strake
2016-05-29 Transom beveled to accept the second strake

Next comes the bevel on the outside edge of the garboard.  This is a rolling bevel, which means it is not a constant angle.  All the strakes have a 3/4″ overlap, so this line was first marked on the garboard.  Since I already had a batten tacked in place to mark the outside edge of the second strake, I used that to my advantage.  Similar to cutting the bevel on the keelson, I used a small stick to gage when the bevel was correct.  The hand plane was best tool for this; a power plane would have been faster but slow and steady avoids mistakes and unnecessary language.

2016-05-29 Checking the bevel on the garboard
2016-05-29 Checking the bevel on the garboard

The next step is to cut the gain.  In lapstrake construction, the strakes overlap one another, except at the bow where they taper and lie flush at the stem.  A tapered rabbet is cut on the garboard to accept the thickness of the second strake.  A rabbet plane is necessary for this task; fortunately I had one which was purchased for the purpose when building Wee Lass.  When done, one side of the boat is ready to receive the next strake.  Repeat the process for the other side.

2016-05-29 Cutting the gain on the garboard
2016-05-29 Cutting the gain on the garboard

Next, spile the strake by building a truss.  One batten will lay on the outside edge of the second strake, another will lay on the outside edge of the garboard which was just beveled.  Fortunately I saved the batten from when I spiled the garboard.  The truss is built just like I had built for the garboard.

2016-05-29 Making the truss for the second strake
2016-05-29 Making the truss for the second strake
2016-05-30 Truss for the second strake
2016-05-30 Truss for the second strake

What follows is similar to cutting out the planks for the garboards.  Each strake has a fore and aft plank.  On the garboard, I cut a plank from the full length of plywood on the forward portion, then cut a shorter piece for the aft plank.  To stagger the scarf joints, I reversed the order on the second strake.  The aft plank was cut from full length plywood, and the shorter piece up forward.  On the aft plank I had to plane a small bevel on the inside of the plank near the transom, to handle the reverse curve on the transom.

Rule #7.  You can never have too many clamps.  Every boat builder knows this.  It is gospel.

Test fit the planks to make sure everything will fit correctly, and mark where the planks cross the molds for ready reference.  Epoxy is extremely slippery stuff, and you’re also fighting the clock to get everything in it’s proper place before the epoxy starts to kick off, or cure.  Like the garboards, I screwed small blocks on the molds so that I could use spring clamps to hold the outside edge of the strakes to the mold.  To clamp the plank laps, I made a bunch of “Oughtred clamps” which provide necessary reach.  “Oughtred clamp” may not be the correct term, but I first saw a description of them in Iain Oughtred’s book “Clinker Plywood Boatbuilding Manual.”  The clamps are normally made out of 1/2″ plywood, but I had some 2×6 lumber from the ladder jig debacle that needed to be gotten rid of.  Simple wedges provide the clamping pressure.  Once again, low tech rules.

2016-05-30 Oughtred clamps
2016-05-30 Oughtred clamps
2016-05-30 Test fitting the strakes
2016-05-30 Test fitting the strakes

Like the garboards, gluing the strakes is a two-step process.  The planks were clamped into position, with wax paper surrounding the scarf joint, and the scarf was glued.  Any epoxy blobs were cleaned up and then the  strake was epoxied to the hull.  It would have been quicker to epoxy the scarfs and the strake to the hull all at once, but trying to do too much at once also increases the chances of a goof.

2016-06-05 Gluing on second strakes
2016-06-05 Gluing on second strakes

The photo shows the actual glue-up.  What’s the difference between it and the test-fit photo above?  More clamps.

2016-06-05 Rule #7
2016-06-05 Rule #7

A close-up of the glue-up.  Rule #7 is definitely in effect here.

 

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