Sabado, Setyembre 25, 2010
Center Board Placement
As some of you will know, the boat building project stalled for about 7 weeks after we had a motorcycle accident, late in June. Construction resumed in August and is back on track in a fast and furious way.....life is too short, go cruising!The sheer clamp was fitted and epoxied into the notches cut into the bulkheads and frames, as seen running along the lower edge of the hull. This becomes the top of the hull and forms the sweeping curve that is so attractive in traditional boats.
Below is a rather confusing looking picture of the sheer notched into the transom. The transom continues lower than the sheer, this will allow the bulwarks to die into the transom.
The battens that were screwed to the bulkheads and frames became supports for cross scaffolding. The battens are long flexible pieces of wood that are stretched across the hull at different angles to "fair" or shape the hull into smooth flowing lines.
The cross hull scaffolding became necessary to gain access to the "top" of the hull for laminating the keel, since ladders definitely could not fit anymore.
Still rather treacherous for anyone other than a billy goat.
During this time, initial attempts at "filleting" were made. This is the process of applying thickened epoxy into corners and running a rounded tool along it to create a strong and slightly rounded "cove" type corner. This strengthens the joint and makes a rounded corner appropriate for glass application. Fiberglass does not make sharp turns well. Richard's first attempt was beautiful, even though it will eventually be buried deep in the aft lazarette (deck storage compartment).
All of the joints will eventually get treated this way. (A lot of fillets) And then the entire interior will be coated with either 3 layers of epoxy or fiberglass and epoxy. In a wood epoxy boat there can be no areas for moisture to seep in and rot the wood. All of the "slop" areas of epoxy on raw wood will disappear as the area gets it's own covering of epoxy.
The keel, which is the backbone of the boat, was applied in five layers. Three of these were 1/2" VG fir lumber with 1/8" marine plywood sandwiched between them, to add resistence to splitting. It was then shaped.
The remainder of the hull was faired to include the keel and the sheer clamp.
Note the crazy shape the keel takes on (below) when it is faired, due to all the curves and angles. The batten must lay smoothly across the hull, and continue over the sheer and keel, at all angles.
Fairing the bow seemed easier in our inexperience with the insertion of the two removable forms seen below.
The next step was to cut a slot in the keel for the centerboard.
A lot of overhead work was required to get the correct positioning for cutting the hole and positioning the centerboard box.
Richard seems to always be too high or too low for comfort.
Finally the Fein tool and Skil saw come out and the cutting begins.
The swing keel box was constructed in two halves, during down time, over several months.
A lot of overhead work was required to get the correct positioning for cutting the hole and positioning the centerboard box.
Richard seems to always be too high or too low for comfort.
Finally the Fein tool and Skil saw come out and the cutting begins.
The swing keel box was constructed in two halves, during down time, over several months.
Research was done for the best type of finish to use on the inside (water side) of the box to prevent flora and fauna from setting up residence. Not a good thing to have a centerboard case full of mussels and growth. Access to the inside is limited since the width is only about 4". We needed something that would retard growth for an extended period (hopefully 10 yrs), and that could also remain potent until the completion of the building process, since many bottom paints need submersion soon after application. We chose "CopperCoat" which is basically an epoxy type medium to which ground copper has been added.
The pretty brown color is the copper in the paint. Both halves were fiberglassed, all edges coated in epoxy and painted in two pieces to assure a good coating, then screwed together. If you look closely at the one half, you can see the fillets at the inside corners.
The long slot was cut into the keel, and through the floor supports that create the bilge and water storage tanks.
Time to call the strong young men to hoist the centerboard box into place.
The hefty centerboard case was squeezed through all the scaffolding and bulkheads, and up into location in the hull.
The keel edge of the box was square so it stuck up from the keel and needed to be shaped after placement.
Lots of epoxy and clamping secures it all in place.
Once the centerboard box was in place, epoxied and shaped the laminated edges of the box can be seen through the keel.
The laminations seen below on the outsides of the keel are the plys of the keel, while the inside ones are the edges of the centerboard box.
At last, a beautiful centerboard box for our swing keel. The slot will continue down through the lead ballast keel when it is cast.
The laminations seen below on the outsides of the keel are the plys of the keel, while the inside ones are the edges of the centerboard box.
At last, a beautiful centerboard box for our swing keel. The slot will continue down through the lead ballast keel when it is cast.
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