Author: Yrvind

I am have now started to shape the bow. Its not evident how to proceed. I am trying to bevel the edges much in the front then let it taper of towards the back. To keep the plywood together I am using trunnels or treenails set in NM-epoxy, because  it is easy to saw and grind them.

Below are some pictures. The plywood is screwed at the edges. If I remove the screws it will fall of. The trunnels are inside the screws. When the epoxy has set I can remowe the screws and bevel the edges.

Below a closer picture.

And one from the front. Click once or twice to enlarge.

The material for the trunnels comes from a flower shop. Its sticks to help the lazy flowers stand up. Flower crutches. I mean what motivates a flower to stand up once its stem has been cut. If I was a flower and a big animal came and cut me lose from my roots. I would not stand up just to please the cruel cutter.

To be continued…

Regards Yrvind.

To be continued…

Regards Yrvind

Its not going to be a plywoodboat, but I cover the moulds with plywood to in an effort to shape the bow to an compound curvature. That way I hope to be able to give Exlex a spoonbow.

Some pictures below.

The first one the bow that I try to make into a spoon shape. It is not evident how to do that but the idea is to make it in stages.

The aft part from above. More plywood pieces is on its way.

The stern.

Screw scarfing the Yrvind way.

To be continued…

Regards Yrvind.

 

 

 

 

 

 

VISITING FRIENDS

As late as Sunday night 12^th of August 2018 the idea was to first to build a prototype of plywood before starting on the real composite Exlex Minor. Somehow, for several reasons, very late in that night I changed my mind. The train of thoughts started with me having problems finding good marine plywood. Some people say that if encapsulate the plywood in epoxy you can use the cheapest plywood. Maybe so but the idea of using an inferior product goes against my grain. Then it was the spoon bow; with thicker Divinycell it would be easier to sculpture a nice round shape, an other reason was that the plywood version and the composite version always would be different due to different skin thicknesses 18, 12 and 9 millimeter for bottom side and deck for plywood versus 25, 40 and 20 for the Divinycell core. A third reason was I was eager to get sailing and would be more motivated if I was working on the real boat. It was a complex decision with several factors working for and against the final decision. During the night I kept tossing ideas against each other. Finally when I fell asleep Monday morning the decision was to go composite. I hope I made the right decision, time will tell.

When I woke up I phoned Anders Lindström at Diab in Laholm, the Divinycell people. Over the phone we worked out what suitable core materials where in stock.

Then I phoned Sten Fransson at Tanso in Jönköping for Carbon fibers peel ply and protecting gloves. He said I could come by. The carbon fiber will be used on the inside laminate to absorb impacts. More about that later.

Finally I phoned Gunnar Malmgren at NM-epoxy in Ytterby just outside Kungälv telling him that I was coming over to the west coast and asked if it was OK if I came by to pick up epoxy

Håkan Johansson at Mekonomen Västervik lent me a big van.

Tuesday 14 of august in the morning I started. My first stop was Tanso Jönköping. Sten took me to lunch and I explained my project and what I needed.

From Jönköping I drove from Ytterby near Kungälv where Gunnar greeted me,

then finally to Laholm. Now it was late. Being frugal I slept in the big car. My money would be better spent on the boat than on a hotel.

Early next morning Anders showed me around in the factory and helped to stove the Divinycell in the car.

On Wednesday afternoon I was back in Västervik. Håkan helped me to unload the car.

Today thuesday 16 of August I have again borrowed Håkans van now to porchase plywood and particle board for the moulds. The ones I made for the plywood version is of no use now as I will build differently. Now I can start to build in earnest.

Below Håkan and the van he lent me.

Below Sten at Tanso

The picture below is from inside the factory, showing a friendly girl tempting me with apples and a machine that works graphite.

Below Gunnar showing me around in the epoxy factory here a mixing machine.

Below a filling up machine.

Below some of the MN-epoxy for the new boat.

Below Anders showing me around in the Diab factory. The machine shown grinds the Divinycell sheets to exact thickness.

Below me and Anders and the Divinycell sheets in the van. My sleeping bag is in the blue sack between us.

I am now safely back home in Västervik working on Exlex Minor. I am thanking everyone supporting me and Exlex through Swish and Pay Pal. Please continue. Your contributions are needed.

To be continued…

Regards Yrvind.

 

Today I cut out the rest of the moulds and put two of them up to take the hull sides. For fun I also placed two more in an approximate position to get an 3 dimensional feeling of Exlex Minors size. She certainly is not a big boat, but thats the idea on the other hand she looks like she will be handy and easily handed.

Below a few pictures. First the frames and mould and me to give scale.

Below: One bulkhead and one mould fixed, parrallell and not twisted and in line, ready to take the hullsides.

Me, Yrvind and some bulkheads and moulds to give scale to Exlex Minor, she has 8 cm or about 3 inches more beam than Exlex. At this stage it is easy to suboptimise and give planty of beam, but give 8 cm to an contortionists doesent matter if she is a “frontbender” or “backbender” I guarantie she be out of her job in no time at all.

When I as a child told my late mother that 5 cm was not much she countered and said it was much on a nose. I think 8 cm extra beam will make a lot af difference on Exlex Minor. She will also be higher in proportion and the hatch in the main bulkhead will increase from 38X40 cm to about 60X60 that is the area will be more than twice as large. Anyway, its an experiment and the only way to find out is to try.

The setup from a distance. The modell in the foreground. The sight pleases me.

About parabolic lines, for those interested in elementary mathematics: The deck beam and sheer line and other such lines are are beutiful if they are parabolic. To find the points, for exampel on half a deck beam divide the distance into four equal parts, that gives five points. Square the distances as below and multiply by how much beam height that is desirebel. The height of any point can be found by taking the fraction to the whole and square the number. Same thing with sheerline, start with the lowest point and go forward and backwards.

To morrow we will here in Sweden have a cooler day after a summer long, killing heat wave. I have not been out running since I been back. The cramped conditions in Exlex have wasted away my leg muscles. To run in that condition whith so much heat I thought not advisible, but tomorrow is time to start.

Health is important. Therefore when I left Irland I started to eat, strictly, only one meal a day. The purpose is to limit insulin which is a poison had in big quantities. Diabetes is a bad disease, they say Alzheimer is diabetes type 3. Its no use having an fantastic boat if you are ill.

What is the value of health?

Ask an invalid person.

To be continued…

Regards Yrvind.

I use a rather improvised method, not the most efficient, but OK and economical if you only design one boat every few years. Below waterline and up to the sheerline I use offsets from a half modell, abowe that I use a simpel analytical method parabolic for the sheerline and and deckbeam, linear for the deckprofile.

I note the measurments on a yellow paper. Becouse I use this kind of thinking not dayly, but rather seldom I often get confused and do mistakes. Fortunately this is because I am not in the habit, not because I am old. I know that because the same things happend to me in the the sixties and seventies, forty, fifty years ago, during the first days on my ocean passages when I was doing astro navigation. After a few days I get the hang of it, but then when I was back to the sextant after buildning a new boat a few years later, again the first days were confusing.

Now like then I just have to be extra careful. Sailing the ocean, the sea looks all the same, luckily making a hull its pretty obvius if you have made a mistake in the calculations because you get a shape that does not look like a good boat.

Below are some pictures. First the half modell.

The notes for station # 500 that is 500 centimeter from the back.

Below some of the bulkheads and moulds. Hopefully they make a fair surface when lined up.

To be continued…

Regards Yrvind.

When I in heavy weather open the main hatch there is a risk of water entering the boat To prevent the water from entering the sleeping room there is a hatch in the main waterproof bulkhead

To be continued…

Regards Yrvind

The best place for ventilation system that will keep Exlex Minor dry inside even when upside down is on the main bulkhead. Like always on a small ocean going yacht things interfere, like the waterproof hatch, the storage etc as well as the incoming air and the outgoing air that has to cross each other. Also the opening for incoming the air and outgoing air be as far apart as possible so that the incoming air does not get sucked out before getting into the boat.

To help me sort out my thoughts I used the mockup in 3 dimensions and two ropes one twisted one braided. By giving them a few extra bends I figured out how to install the ducts. – Each bend reduces the airflow so I had to make as few as possible. Where I made a bend I increased the channel diameter to compensate.

To new readers the system works on the principle that water enter the ventilation channel cannot rise above the sea level. Hence the ducts start by crossing the boat athwartships then descending to as far as possible.  That way whatever angle of heel, even upside down some part of the ducts of both the incoming air and the outgoing air is always above the waterline, thus blocking water from entering the boat. See earlier posts and illustrations.

Below a picture showing how the ducts are bendt.

Below showing in detail the extra bends of the brided rope.

Below a picture of the main bulkhead. The thin lines indicating where the door to the sleeping room is, is probably to thin to been seen.

The below illustration is by Pierre Herve showing the slightly different ventilation on Exlex. Thanks Pierre.

To bee continued…

Regards Yrvind