Number One Hull Strakes...

It seems that this stage has been a long time in coming.  I am finally putting together the pieces that make up the hull.

The number 1 strakes, port and starboard are the closest to the centerline of the boat.  Here they are being fitted to the keel trunk.  There is a rebate cut on what will be the outside of the boat to fit the flange at the bottom of the keel trunk.

The port and starboard #1 strakes on the bench to dry fit the puzzle joints before gluing. This is the outside surface of the strakes with rebates cut around the perimeter.  There will be an extra layer of fiberglass tape to reinforce the joints where the panels meet and the rebates take up the extra thickness of the fiberglass at these joints.

The port and starboard #1 strakes on the building jig for a dry fit.  Fiberglass cloth and epoxy resin will be applied to these surfaces next. 

The puzzle joints have been glued and the panels are ready for a layer of fiberglass on the inside surfaces.

A bit of a bump along the way.  A bearing in the motor of my very old table saw seized up.

Here 10 oz. fiberglass cloth is being draped over the port and starboard #1 hull strakes.  Underneath the roll of 10 oz. cloth on the wall rack is a roll of 6 oz. cloth that will be applied to both sides of the bulkheads and other interior parts.  A layer of plastic over both rolls keeps most of the dust off.

A box with a 40 watt light bulb inside covers the epoxy resin and hardener.  The light generates enough heat to make pumping easier.  Each part of hardener needs five parts of resin to cure properly.

 I use a kitchen scale to measure the correct proportions of resin and hardener.

Hull strake #1 port with cloth and one coat of epoxy applied with a roller.  Another coat of epoxy is applied later in the same day to cover the weave in the cloth.

The second coat of epoxy has been applied.  When it is cured there will be a "blush" on the epoxy that will be removed with a water scrub before sanding.

The Stem...

I bought 2 nice spruce planks from Russell.  The keelson will come out of long one on the bottom.  The top one was ripped into thin strips which were then glued together over a mold to form the stem. 

Brandon cut the parts for the mold on his CNC machine.

Here is the assembled mold ready to take the first spruce strips.  There were four separate gluing operations.  The mold was covered with plastic packing tape to keep the stem from sticking to the mold.

I added plastic-covered guides (you can see one set between clamps 2 and 3 on the right) to keep the laminations from slipping sideways.  Each laminate was coated with straight epoxy on both sides first.  Then I went back and used a notched trowel to add a coat of thickened epoxy to each side of each lamination before clamping.

Here is the first lamination after the epoxy cured.

Gluing layer number 2

Layer 2 cured

Layer 3 doesn't need the full length of the mold.

After layer 3 cured, the whole thing was taken off the mold to glue on cheek blocks.

Finally, the assembly was spot glued back on to the mold ready for machining at Brandon's shop in Port Townsend.

The finished stem turned out nicely

A closeup showing a reference line that was machined at the same time as the part.

Plywood parts and the keel trunk...

All the plywood parts (I counted 176 total) for the boat were precision cut on a CNC machine by Brandon Davis at Turnpoint Design in Port Townsend.

Brandon and Eric discussing the fine points of a
design on Eric's laptop.

The five-axis machine that did the cutting.

It doesn't really look like a boat

I built a rack out of pvc pipe and some
fiberboard to keep the parts
off the floor and accessible.

While I was busy putting the jig together, Russell Brown created the keel trunk which is the heart of this boat.  Everything will be built around it.  I had Russell do this as it needed to be done absolutely right.  It is highly engineered with many parts and carbon fiber fabric.  I didn't think I was ready for this kind of part just yet.

Eric and Russell with the deck end of the trunk showing.
The two sockets visible to the right of the 2x4 will take the
crane assembly that will lift and lower the keel in the trunk.

A beautiful piece of work - less than 40 pounds!

A look inside

The trunk on the building jig adjusting to plumb with the laser.
The top of the trunk is attached to the rafters to hold it in position.

Next, the bench and building jig,,,

There are so many things to do (and dollars to spend!) to prepare to build a boat before actual construction. I learned a lot from reading the construction manual of the PT Skiff.  Russell and Ashlyn Brown sell these as kits in Port Townsend, WA.  Russell is an exacting, master boatbuilder and has helped me a lot (wait until you see the keel trunk he made for me!).  The PT Skiff and the Shilshole 27 make use of the same concepts - they both came out of Bieker Boats.  They both use advanced wood/epoxy techniques to make a very strong boat for the weight. They are both stitch-and-glue on a building jig.  Russell has written a companion document to go along with the PT Skiff construction manual.  It is a short, concise document on epoxy techniques that Russell has learned after many, many hours of using these materials.  Another recommended book is The Gougeon Brothers on Boat Construction.  I am using their West System epoxy.

The Shilshole 27 is made of Okoume plywood - 9 mm and 6 mm.  The plywood comes in 8 foot lengths and so must be joined to make up the long pieces necessary for the length of the boat.  To make these joints strong they are made to snap together like a puzzle and that's what they are called - puzzle joints.  To glue all the pieces necessary for the total length of the hull, a good long working surface or bench is necessary.  Using Russell's procedures, the parts are held in place during gluing by clamping boards that are screwed through the parts and into the table, making sure that there is plastic sheeting (or wax paper) on both sides of the parts to keep the epoxy from sticking where it shouldn't.

Here is a glued puzzle joint on the building jig

I made my bench surface of white melamine board.  Incidental glue and epoxy can be scraped off and I can trace the outline of adjacent parts on it with pencil to preserve the alignment of the parts.  I used 3 - 4' x 8' sheets so my bench is 24' long.  Some of the parts will hang over the edge while gluing, but as long as there are no puzzle joints near the ends it is OK.  For longitudinal support I got 2 - 24' I beams from my local lumber store.  At the same time I got 2 - 16' I beams for the building jig.  The bench legs are 2 x 4 thru bolted to the I beams with diagonal bracing.  I like a high bench.  Mine is 39" off the floor.

Assembling the building jig on the bench

Gluing the longitudinal for the building jig

The building jig is the foundation of the boat so I took pains to make it as accurate as I could and added reinforcing to take the weight of the boat.  Finally I added 10 leveling screws and got a group of guys to help me lift the building jig off the table and place it on the floor.

Here is the aft end of the jig showing some
of the reinforcing and one of the leveling screws

The jig on the floor.  You can see the strings that were
used in combination with a laser to level the jig on the floor.
The keel trunk is in the background.