The last episode pioneered presenting the completed component first, followed by discussions of the details. This led to no great out cries and may contribute to comprehension of my efforts.
You may recall from the last episode that crossbeam progress was limited by the epoxy and lumber supply. Two of the four crossbeams were constructed up to a point requiring vast quantities of unavailable epoxy. The lumber shortage remains, but the epoxy shortage does not. We'll pick up beyond where we left off.
Mast Crossbeam
This 14' 9" mast crossbeam will be located just forward of the cockpit. It is the longest and most complicated of all the beams. It has been enveloped in fiberglass and hand sanded. The mast step is located on the beam's top center. The step distributes the mast compressive loads onto the beam structure. A dolphin striker, not yet installed, counters these compressive loads on catamarans. To either side are semi-circular access ports located near the points where the beam is lashed to the inboard hull sides. These ports allow access to anchor points for high strength synthetic line to pass through a hole, in the beam underside, to a centered standoff (not installed) three inches below the beam. The line then returns inside the beam to attach to the opposite side anchor. Tension on the line distributes the mast compressive forces to the hull attachment points rather like an upside down suspension bridge.
If you look carefully at each end you will find a cleat. These cleats will be used for bumpers, springer lines and a future cockpit tent.
I learned late in the process that the beam work was much easier on the saw horses rather than the bench. I could access all sides and roll it over as required while completing the endless sanding seated.
The first task is to complete the five full length fillets along the beam's length. These fillets reinforce the bonds between the 3/4" plywood web and other components as well as providing a smooth transition for laying fiberglass. Of course these five full length fillets will require sanding by hand before fiberglassing is possible. Here the yellowish fillet is reinforced with a three inch wide strip of fiberglass along its' length. The gussets and other beam interior surfaces have received the finial coat of epoxy before a fairing will cover these surfaces. Beam areas epoxied to the fairing are sanded as well.
Cutting out a fairing requires a template. A strip of 3/8" plywood spans half the fairing width and is wire tied through gusset holes, conforming it to the fairing curve. Small sticks are hot glued to the plywood to define points along the fairing edges.
In the first attempt at this, I used a piece of limber lumber that distorted when the wire ties were tightened. This resulted in a fairing half that did not fit and I have no material for a redo. I was lucky to find it could be made to work on the other end with some extra labor.
The template is laid on the fairing material and marks are transferred from the stick ends onto the material. Nails are driven into these marks and a batten is clamped to the nails. The batten creates a smooth curve that a line is drawn against to define a cut line.
Works like a champ!
The fairing is faired. Notice the outlined area on the lower left beam's end. This wedge shaped area is a sixth epoxy fillet running the entire length. It may have taken a week to complete as only so much epoxy can be applied and still maintain its' shape until it sets. Of course sanding is required before each epoxy application. I considered using wedge shaped lumber to fill much of the void, but thought it would be too much of a juggling act as the wedge and fairing are best adhered at the same time. The wedge idea will be revisited on the next beam.
A early image of the inspection port and cover for the dolphin striker anchor. The anchor is a 3/8" stainless steel bolt passing through two and one half inches of lumber to an imbedded nut. As with all fastener holes, the holes are drilled over size and then filled with a high density epoxy. The filled hole is then drilled to fit the fastener. This arrangement prevents a pathway for water to enter the wood as well as provides better bearing surfaces for through fasteners and threads. The inspection ports and covers received epoxy filled fastener treatments for all six cover retainer screws.
The first post fiberglass sanding in progress. Hand sanding produces troublesome callouses where the finger nail edge meets the flesh. My callouses from sanding the hull were just beginning to sluff off when I again had to seek the zen of sanding in the beam construction. The taped up fingers offer some protection, but are not the hot ticket. One taped finger tip I've learned is to use the regular cream colored masking tape as it will not unravel like the shown blue painter's tape. This may be the first post fiberglass sanding, but not the last before the beam is fully completed.
Aft Crossbeam
Surely, some may find endless amusement in my trials by sanding. I must soldier on to achieve the goal of beach bars and bikinis for evermore. To that end, the 14' 4" aft cockpit beam construction is well underway. The full length epoxy fairing fillet will soon be ready for shaping by sanding. The wooden wedge filler idea was abandoned as the available lumber would not permit me to keep my fingers while making the cuts.
Painted Hulls
Then there were two... Epoxy primer and top side primer arrived on a recent shipment. This enabled the application of top side paint and antifoul paint on the starboard hull. It has been unusually cool for late spring and early one morning I was able to apply one coat of topside paint that would flow out to a smooth finish. Additional coats will be necessary, but that will have to wait for cooler times.
The hull was inverted for the painting process. It is always a dicey process inverting or righting a hull. The hull suspension/rotation lines are beginning to show signs of fraying. I hope I have inverted the hulls for the last time, but this may mean that at some point I'll be lying on my back and reaching up to sand a hull. Ugh, where is the zen in that?
