He ask if it is not better to have more dense material in rudder and centerboard as not to stability due to flotation.
Heavier materials low down will give more stability. Added lead will give even more stability. In the case of the centerboard, when the board is raised, more weight will make the boat lose stability.
Almost every boat is designed as if it was to be a racing boat and the same with books about yacht design. Exlex is intended for cruising, when cruising I sail mostly down wind, even though I plan to round Cape Horn, 50° south to 50° south, east to west. Exlex is designed as a low energy boat and cruise at low Froude numbers around 0.3 this reduces the energy needed to about 1/6 of a conventional boat. See my Manifesto for a more detailed explanation.
More weight in the appendices will put more strain on them; they have to be designed more heavily. This added weight would make the boat slower down wind. It will also make the boat bigger and heavier and more expensive.
I think most boats are sub optimized for windward work. Neither do I think a cruising boat shall have weather helm.
I have done more mock up, now in the saloon. I now have a pretty good idea of the finished boat. Exlex Minor have turned out very roomy despite being only 4 cm longer and 19 cm vider than Exlex that was indeed very cramped. Exlex Minor have definitely place for two persons friendly persons to cruise long distances a boy and a girl.
Edition Paulsen did 11 of October publish a book titled 100 Marin. Its a selection of famous yachtsmen from the last 150 years including Jules Verne, Bernard Moitessier, Francis Chichester, Jack London, Naomi James plus 94 other equally famous person and me. Its a mystery how I got included, but I am proud to be included in that crowd.
Below are some pictures click on them once or twice to enlarge.
I have started to build up the hullside from the stern. Two sheets on each side are now in place. Aft is the easy part, like building a box. Simple structure, but nothing is gained by making it more complicated.
Below two pictures.
First placing the Divinycell in a good position. Important when you are working alone. Adding the NM-epoxy. Clamping it on trying to get as good a fit as possible.
I am now building up the mould. The plywood has to be faired to fit. First I do a rough fit with the help of a spline and some lead weights of the sides. After that the bottom sheets is put on. Now I am fairing with surfaces instead of lines. That is far easier.
The aft part of Exlex is ready for the Divinycell. The spoon bow will be much more difficult to get a good shape on. I will take my time to do good work on that.
Below some pictures.
First me with one of my favorite splines. I have had it for many years and faired many boats with its help.
Below a close up of the same spline or batten.
Below, aft end of Exlex ready to take the Divinycell sheets after first being insulated with plastic film to prevent them from sticking to the mould from epoxy that finds its way there.
The page “Exlex Minor the Idea” is uppdated 25 August 2018
Yrvind is now on Porto Santo. He has decided to restart with a new boat. ExLex, which is basically an experiment, has some issues that must be solved. For example is the boat too heavy, which affects both speed and stability. There is a serious problem with the stering control that causes the rudder to lock. It is too cramped inside and it has not been possible to handle the sail from the front hatch as it was intended. All in all, this means that Yrvind decided to make an restart and design a new boat where these problems is corrected. Yrvind now needs to rest and comes when he feels ready with a status update here on the website.
Yesterday was a difficult day with grey skies and much wind from the side which is the worst. Many times I had to go on the wobbly foredeck to work the centerboard and sails. This is not how it should have been done. It should have been done from the safe position of the fore hatch. The road to hell is paved with good intentions. At first everything looked fine, then in the last days when the timetable was set, came a rush. The forepeak got filled up and its intended use as a safe place to handel the sails and centerboard was temporarily sacrificed. I eat myself to more space was the idea.
Surprisingly even after eating for now more than a month it seams as if I have as much provisions as when I left Ireland. I still have to work from the outside from the foredeck. Unfortunately because I do not feel completely safe there in the dark when the boat is healing rocking and yawing. Then the night was difficult to but in a different way. I am now in the really shipping lines for traffic to and from the Gibraltar straight. Some was coming very close. It is difficult to know if the crew is seeing me or not and I hate to bother them by calling them on the VHF. Everything went well and I awoke to a wonderful day. The wind had calmed down and the sun shone brightly from a clear blue sky. It was wonderful and very nice and warm. Then the horror of it, the port rudder did not work. It had jammed and was blocked in a position. I tried everything but to no avail. What to do? I did some thinking. I was sailing south. The hot morning sun did strike the port side. I have inside steering and no wind-vane or autopilot. The pipe steering lines goes to my bunk. I do not want any water there, specially not seawater. The trough hull connection consist of a piston mobbing in carbon fiber. To each end of the piston the steering rope is attached. Thus breaking the wicking effect and making it waterproof.
My boat is very narrow only 104 centimeter. She floats to deep and is very tender and rocky. I therefore use a lot of antislip tejp. They come in two varieties, black and white. To my yellow boat I thought black looked best. Black do get very hot in the sun, in fact it is uncomfortable to touch it. The heat produced by the black antislip tejp had so heated the piston that it had expanded and jammed in the pipe. I have now pealed it of. Now the piston is cooled and it seams as if the steering once again is a working construction. I have wanted to mention this as an example of how two things at first not connected to each other can interfere and cause big problems. One can not new things without testing them. Problem is here at the latitude of Gibraltar the sun is much stronger than in Sweden
I have a nice time out here. I spend my time working on Next Design which is coming out most satisfying.
Update to sailing report 6
I still have a problem.To day again the sun is shining brightly. Again the port rudder is blocked. I was happy yesterday. I thought I Had solved the problem by removing the black anti slip tejp. I hope I can come upp with a solution.
Update 2 to sailing report 6
The rudder problem gets worse and worse. Now in the afternoon when the sun comes in from the other side also the starbord rudder is blocked. I cannot steer my boat. Its a bad thing. If a ship is heading for me I cannot move out of their path. I try to find a solution.