With the 3 hulls now painted I am working on all the little things remaining. Once the folding system is fully assembled and working the rest will be smooth sailing...
The centerhull is quite light. I dont know the actual weight but I can lift one end easily by myself. My target is to keep the whole assembled boat below 1K lbs. On the other hand it is very difficult to manipulate the floats. They are light (200 lbs with 2 beams attached) but they are cumbersome. Once attached to the folding struts, they are finally docile.
Work on the centerboard slot. Notice the way I cut the slot when making the centerboard case. I left some panel segments to prevent the solt from deforming. It was easy to cut at this stage whithout any measuring to do. It is nice to have the slot off-center since it becomes accessible by leaning the hull on port.
By changing the position of the centerboard pivot I was able to reduce the length of the slot by almost 300 mm, while still keeping te centerboard at the specified length. My experience building 8 Fireball dinghies inspired me to do this. A short slot is good because it reduces drag and it is also quicker to build.
I replaced the foam core all around the edge of the slot by epoxy putty because this is a highly loaded area, especially since it is at an angle to the bottom of the boat. Complex shear and bending stresses are present at the area where the centerboard exits the hull.
I used 3 layers of fiberglass to complete the centerboard case structure. I used peel ply to make a nice job and reduce the amount of sanding required.
After cure and removal of the peel ply, I "bogged" the slot for later fairing.
Finished job. The work on the centerboard slot was quite easy and quick. The only difficulty was the glassing of the forward part which I modified. It goes forward over the bottom panel and is very difficult to reach. If I build another scarab22, I will improve this (!). I wet sanded the cured epoxy-aluminum mixture to match the rest of the bottom.
With the centerhull now completed I am working on the folding struts in preparation for final assembly. I am making fiberglass channel profiles to act as spacers between the aluminum parts made by Erik Precourt. I use a MDF mold covered in packaging tape. I just unscrew the mold to get the part out.
I used latex house paint on the fiberglass to protect from UV and to give a nice yellow color! I love this color! Note the aluminum rivets I am using to assemble the struts. They are solid rivets that I "buck" with a hammer. It works very well. I like the relative flexibility of this arrangement. I know the all this stuff will be flexing when the boat is sailed hard and the fiberglass parts and their rivets will yield a little to prevent uneven load distributions.
Starboard folding struts in place with float attached. I am installing the hold-down "studs". They are 316 stainless steel bonded in a hole drilled on the top of "spars". I bought them at McMaster-Carr already cut at the right length. This is a departure from Ray Kendrick's design.
Starboard float attached.
Bonding hold down bolt in place.
Installing chainplates. I bolt them from the inside-out with "weld nuts" on the outside. When the bolts are cut at the right length, the outside surface in smooth. The Schaeffer chainplate is a perfect match with the Precourt deadeye. A better way to attach the chainplate would be through the deck onto a strong bulkhead.
Cutting more access covers on the float. I use three holes per floats. They fit between the float bulkheads and give access to the chainplates and to the future net attachment points. The nets will be laced to the float so that I can reach through the lacing to open the covers.
Installing the cockpit locker covers. The screw hole locations were filled with putty before the paint so now I just have to drill the holes. The plastic hatch can be seen in the background.
Forestay - bowsprit fitting. I think it is overdesigned but the Harken furler fits really nice on it. It is lightly sealed to the deck with silicone because I expect to remove it eventually, at least to have it electropolished (now it is just sand blasted).
Float nicely folded, snug on the centerhull!