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.
The deck is now laminated on the outside. Inside I have to do the fillets and taping so the boat is now uppside down once more.
I have also weighted the boat she came out at 426 kilos. That is to my liking becouse her waterline is 5.5 meters or 18 feet. There is not much more to add except the rudder and centerboard the hatches and a few odd and ends. Anchor and lead batterys will also add weight but a guess is that the painted boat will be about 600 kilos me and food and water for 60 days will add about 200 more kilos. To me it seams reasonable the she will weigh about 800 kilo at the start of a ocean passage. That gives a displacement ratio of 137. Most cruisers land somewhere between 300 and 450 at the start of a passage, racers are lighter. The figure for to be able to plane given is belov 150. There are of course other criteria for to be able to plane as a suitable hull form. I think Exlex minor has such a hull. Where she does not shine is sail area to displacement, but wind pressure increases with the square of wind speed. Given enough wind and down wind she might be able to plane, but that is speculation. Hopefully I might find out coming summer.
I have been working on the ventilation systems for weeks adding piece to piece usually six a day to the ducts. The two ducts for incoming air and outgoing each cross the boat just below the deck two times, then incoming air is ducted down to the bilges outgoing air ducted from bilges up to the deck. There is also water seals to prevent air escaping but letting spray out. This work is not really visible , but it is done and I am finished with it and I am happy about that becouse it has been drawn out and made me work long houers. Also done is most of the work in my sleeping room and in the aft saloon.
The fore deck on the other hand have been done in a few days and have changed the look of the boat very much.
Byrålådseffecten a english translation would be the drawer effect: This is what we engineers call the nuisance when a drawer gets stuck in a chest of drawers and it does not only happen to drawers; it happens to most sliding things that are wider than deep. It is a pain.
To avoid it I made an analyses and it turns out that the solution is surprisingly simple. Drawers that are wider than deep have little guidance and therefore not always move straight but turn. When they turn the short side of the drawer is not any longer parallel with the guiding sides. The drawer takes more space and gets stuck diagonally. The more you pull the worse the drawer gets stuck.
I said to myself: what geometrical figure does not get wider when it’s turned, obviously the circle, by definition. I use part of a circle segments have been cut away to make it almost like an rectangle. In this case when using it as a lid for the anchor locker I only lose 15 mm on the corners. Pictures will illuminate. A big lid would be to cumbersome so I devided into three peices.
Below some pictures.
This idea of preventing narrow sliding broadside to jam can be used on many applications. Companionways are mostly shaped narrover at the bottom that the washboard will not get stuck by the byrålådseffekten. Its a bit magical how easy the boards now slide thanks to the rounding of the corners.
A place for everything and everything in its place. It is important to get thing secured and easily accesible. That requaries a lot of detail and that takes time.
The arrangement for my bedroom is now nearly done. Today I finished lockers for my note pads. They are in A4 format and square lined 5 mm. Kollegieblock we call them and I really love them. I have used them since the 50-ies. They are exellent for drawing boats on using scale 1:40. One square then has a side of 20 cm, half a square is 10 cm.
Ipad and small computers also fit there. Two of these lockers are on each side. I use sliding lids. They work well I have used them on a few boats before 1968 the first time and on Exlex now 2018. The present ones are made of Tufnol a nice material I find.