Posted 30 March 2012 - 07:53 PM
I used a laser to connect the dots, so to speak.
Here's a few of the new stringers installed. They're rather discontinuous, for several reasons. I want to be certain that any water is able to drain. It's also difficult to get the new stringers to bend in 2 axes, which would be necessary for them to exactly follow the edges of the planks. Also, I'm doing this one section at a time, as I don't want to remove all six bulkheads at once. So, it's short stringers with little joiner pieces (not installed yet) across the limber holes.
Posted 02 April 2012 - 08:38 PM
I assembled a right-angled frame to clamp to the gunwale, to act as a reference for installing the sections of the new bulkhead.
The first parts cut out were the knees. These are closeups of port and starboard, bulkhead #3, with the 2" thick top edge of the bulkhead temporarily clamped in place.
The limber holes in the centre section of the boat have also been completed, with a piece of 1/4" plywood to bridge the opening in the stringer. The limber holes will all be coated with S1 Sealer, once all the bulkheads have been replaced.
Posted 05 April 2012 - 01:56 PM
Test fitting the lower sections of the bulkhead:
Creative clamping for the centre section. There's nothing to clamp against, so I clamped a block of wood to serve that purpose.
The lower edges were coated with S1 Sealer to guard against water ingress:
Partway through the installation:
The final product, resting while the glue dries:
Posted 28 April 2012 - 09:55 PM
With the stringers out, I sanded away the paint in this area, and then coated the entire aft section with S1 Sealer. This was followed with thickened epoxy and fibreglass, with balsa as a filler along the keel/garboard joint.
This is the keel, at the aft section of the centreboard slot.
Posted 28 April 2012 - 10:03 PM
I used small plywood blocks as doublers, to hold the end of the stringers in place while the glue dried. They were installed with staples from a pneumatic gun.
Posted 28 May 2012 - 03:25 PM
Bulkhead 6 glued in place, with the hole cut for the inspection port:
Templates for the knees on bulkhead 5:
Bulkhead 5 installed, showing the view to the transom:
Posted 29 May 2012 - 07:48 PM
Posted 11 June 2012 - 10:04 PM
With all this complexity, I started in CAD. Here's the design for the step for the main mast:
I cut out the parts from 3/4" plywood using my MechMate CNC router:
The layers were then glued and clamped. The old step for the main mast is in the foreground:
Here is the step for the main mast, temporarily installed:
Posted 11 June 2012 - 10:18 PM
The planking has a fair amount of twist in the bow, so I decided to install a double layer of 1/4" plywood as the stringers in this area. The plywood is more able to conform to the twist than solid wood stringers. Extensions were also installed at bulkhead 1, so the stringers will be discontinuous, as they also were at the stern, providing limber holes inside the watertight compartment.
The template for bulkhead 1 was done in two sections, which were then taped together:
Bulkhead 1 was then cut out of 3/4" ply, and test-fitted. The bulkhead now extends to the height of the gunwales, and the deck will be at that level too. With the planking already installed, it was not practical to install the foredeck at the level of the seats -- normally it gets installed before the planking goes on.
Posted 12 June 2012 - 07:57 PM
Posted 14 July 2012 - 04:12 PM
Approximately 200 screws were removed, and the holes countersunk and patched. These were for the original stringers. The replacement stringers are only glued in place.
Posted 14 July 2012 - 04:24 PM
What it looks like with the deadwood clamped in place:
The garboard strakes were joined on the outside with epoxy and biaxial fibreglass.
The wetted surface was also coated with S1 Sealer, except for the area near the centreboard slot:
Posted 14 July 2012 - 04:30 PM
I decided to lift the boat sideways, so that the epoxy would tend to run into the joint, not out.
Materials prepared for epoxying: bamboo taped above the correct position, and strips of biax:
The entire side of the stem is now glassed, and will later be painted white.
Posted 07 September 2012 - 02:55 PM
Posted 17 September 2012 - 07:18 PM
I tried templating the CB trunk with cardboard. That didn't work, as it was way too wobbly. I ended up using the intact piece of the old trunk, and added parts on to it to match the shape I wanted.
All this work was done with the boat inverted, as this was the only way to have clear access to the middle of the hull. The template was suspended through the centreboard slot with blocks and clamps:
These photos have been rotated to the right-side-up view; the boat was still inverted during this work.
The reinforcement for the mizzen mast step was also clamped in place, as my redesign of the CB trunk comes very close to the mizzen mast.
The knees for bulkhead 4 were clamped in place, with a length of plywood to span them and give a vertical measurement for the CB trunk. Remember again that this was all done upside-down. The work was confusing, to say the least.
Wood rails were glued to the upper and lower edges of both sides of the trunk:
Test fitting the trunk. The gray tube at the back is for the bilge pump discharge.
The inside of the trunk was coated with S1 Sealer (three coats). The mating surfaces of the triangular parts at the front were left bare, for a primary bond with the wood. A vertical piece was not installed at the forward edge of the trunk. I did not want to have any sealed compartments, so a drain hole was installed at this small enclosed triangle.
Blocks, covered with packing tape, were clamped against bulkhead 3 to guide the CB trunk during installation. At the aft part of the slot, two wedges were clamped into the slot to guide that part.
The CB trunk with glue applied, ready for installation. Note the rope bridle hanging down with a hook. This was used to levitate the trunk over the boat, and to slowly lower it into position.
My Dad helped with the installation, as it took four hands to lift the boat and then to guide it over the middle of the boat.
Once the trunk was installed, the router was used to cut the planking to the exact width of the trunk.
Posted 18 September 2012 - 09:14 AM
The old trailer winch, clamped to the gantry crane. This was used to levitate the CB trunk into position:
Forward view, showing the guide blocks at bulkhead 3:
The trunk in position. The lifting bridle is still in place.
Details of the forward and aft sections:
Overview of the boat at this stage:
Posted 18 September 2012 - 12:09 PM
The knees were first clamped in place. Then the horizontal pieces were clamped, and the verticals next to the CB trunk. This gave enough support to template the remaining curved section of the bulkhead.
The L-shaped sections were glued together prior to their installation in the boat. As the alignment was critical, I set up a jig for each piece.
Taped blocks were used to spread the clamping load, and to prevent them being glued to the bulkhead.
The lower edges of the bulkhead were coated with S1 Sealer:
The bulkhead, clamped in place. My brother Camille helped with this part (while visiting on vacation).
The view from astern:
Posted 18 September 2012 - 07:44 PM
Posted 18 September 2012 - 07:49 PM
Also tagged with one or more of these keywords: penobscot lapstrake, rebuild
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