NOW I HAVE A HULL

Its a small step for mankind but a huge one for me. I have a hull and I am very happy about that.

Please keep support my project.

Her weight is 182 kilos. Her lenght is 580 cm. Her beam 123 cm, same as Matt Laydens Paradox, a boat a have sailed a lot. I have not copied Matts beam. Its convergent evolution. Concerning the weight I am happy about it and in general with the work so far. Everything looks very promising.

Below 3 pictures.

Exlex Minor is a big enough boat for an old modest man. There is even place for a small girl. Only a show-off has use for a bigger boat.
The boat is weighted for and aft. Here the scale showing the forward reading of 50 kilos.
Adding the numbers. Forward 50 kilos and aft 132 kilos gives a total of 182 kilos. Exlex Minor have a very strong bottom. The Divinycell has a density of 350 kilos a cubic meter, also there is several layers of glass fiber on the bottom for beach landing. I have also done a calculation of the center of gravity by measuring the distance between the two points of weighing.

To be continued…

Regards Yrvind

MORE ABOUT CARBON ON OUTSIDE OR INSIDE

Yesterday I showed some pictures about why I have chosen to put the carbon fiber on the inside of the Divinycell instead of the outside.

Below are photos of tests I made about 15 years ago. Those tests convinced that placing carbon fibers on the inside of a sandwich construction makes it way more stronger than to have them on the outside, regarding impacts.

These two samples each are laminated with carbon fiber. The left one on the inside, the right one on the outside. Hitting them with a big hammer the right sample was easily penetrated the left one got a dent but no more.
The inside of the same two samples. The left one with the carbon on the inside shows no damage. The right one with carbon on the outside is completely penetrated.

Clearly the difference to impact impact is like day and night. It is no more difficult to or not much more difficult to put the carbon on the inside than on the outside, but it so much more safe. My advice to builders of small ocean going cruisers: Use carbon fibers on the inside to get a strong safe boat.

To be continued…

Regards Yrvind

WORK ON THE INSIDE

Exlex Minor is built using the sandwich princip, an superior way concerning weight, stiffness, strenght, insulation and flotation. The boat has however to be laminated on outside and inside.

After doing the outside lamination with the help of friends I have now started on the inside.

Before that the mess created by wrecking the mould had to be gotten rid of and the inside surface shaped to a nice finish.

Below are some pictures.

The boat turned 90° the moulds was glued to the flour but with the help of a big hammer, – laying in the left lower corner of the picture, – they were smashed, letting me lift hull and and mould and turn it over with the help of the chain hoists.
A view of the inside of the bow, a lot of things to get rid of well scruwed together and glued, but by getting at a week point I succeded to get rid of the lot.
To fair the hull I used plywood. Most of the boat was hard chine. I however wanted a spoon bow therefore I cut away the edges at the bow. To keep the plywood together I used the kind of sticks ladies support their flowers with as can be seen here. One stick does not give much strenght, but plenty of them adds upp to a stiff construction.
The mess. Håkan kindly lent me his big Mekonomen van. I drove the mess to the dump. I have a driving licence. I got it August 1957. I have used it a lot. The police have never cought me for speeding parking offence or any other bad deed. The should give me an award after 60 years of good driving.
The inside was not even. It had to be grinded and sandpapered to a good even surface. It took many hoers of hard boring work, but in the end it was well worth the effort and it shore gave me a lot of pleasure to see the result. It made me plenty happy to get such a nice hull built by my own hands, not to forget the help from my friends.
I use carbon on the inside. There it contributes very much more to strenght than if I had placed it on the outside, becouse on the inside the fibers takes up tension forces distributed by the Divinycell over a large area. The tension forces has its origin in much smaller local compression on the outside skin. It makes all the differences to the safety of the boat. I would say for all practical purposes this configuration makes Exlex unbreakable. It feels nice to sail such a thrustworthy boat on the big routhless ocean.
Working om the bow I leaned the boat forward. Working on the side I keep the boat heeled over. Arranging your workpiece makes work more comfortable. It is also easier to apply the NM-epoxy and the Tanso carbon fiber.

To be continued…

Regards Yrvind

LAMINATE DONE

Today my friends have helped me to laminate Exlex Minor with NM-epoxy. Everything went very well. Good epoxy and very competent friends. An important step towards new adventures.

View of the stern
View of the bow
I spent the all my time mixing the NM-epoxy using the two pot way and measuring the component on a scale to the tenth of a gram. Only the best is good enough for Exlex Minor.

Some of my friends have helped me for decades. They have much experience and we all agreed that this was the best laminate ever of all the ones we had done. Also the best shape of all my boats, a good omen for coming voyages.

I will try to get more pictures from my friends who took pictures during the laminate.

To be continued…

Regards Yrvind.

PREPARATIONS DONE

Now nearly all preparations for the lamination is done.

Today Petter helpt me to cut the glassfiber. I had not so much glass fiber as I thought. Had I had more glassfiber I would have cut more for more layers. Still this will be fine, more than enough strong by most judges and the boat will be a bit lighter and that is important.

Me and the glass fiber. Petter took the photo.

The day of the September equinox Sunday 23 of September at 9 AM we, my friends and me, will start the lamination of Exlex Minor. It is a big moment, much depends on the succesfull outcome and I am a bit nerveus although I could not wish for a better team.

To be continued…

Regards Yrvind

GUIDED TOURS FOR GROUPS

Are you a group of persons interested in small ocean going boats like Exlex Minor. Welcome for a guided tour. The fee is € 700 poor groups gets an price reduction. If you are rich you have to pay more. The money goes to the research and development of Exlex Minor.

Thursday 13 September a group from School of Industrial Design visited me
Today Friday September 14 a group of kayak people visited me.

Regards Yrvind

THE NM-EPOXY HAS ARRIVED

September 12 2018

More of the NM-Epoxy for Exlex Minor from Nils Malmgren Ytterby has arrivied. My plan is to make a very strong bottom on the boat. It is good for handling the boat on land and I an emergency gives me the option run the Exlex up on a beach. The only place on Exlex where weight is advatageus is on the bottom.

Sunday morning 23 of September me and my friends plan to start to laminate the outside of the hull.

Most of the preparations are now done so there is not much more I now can do except relax a bit before the lamination is done. When done the boat will be turned right side up and lamination of the inside commence and the bulkheads.

The NM-epoxy arrived today. A big moment.
One more photo of the bow. Do you see any improvement? I have been sandpapering the hull houers after houers hopefully its getting smoother.

To be continued…

Regards Yrvind

WAVE PIERCING OR A HULL WITH HIGH PRISMATIC AND SPOON BOW

Today racing yachts strives for a wave piercing bow. To slice through a wave instead of having to fight your way through it sounds like what a strong man should do.

Racing yacht and cruising yachts are different kind of boats. A racing boat is often built light and driven hard to windward a cruising boat is heavier and the sailing is more relaxt, its course is mostly downwind.

A cruising boats max speed or hull speed happens when the bow wave and the stern wave join each other and become one, creating a trough so deep that the boat is captured in it and can only travel as fast as the wave. The speed of the wave is the square root of the wavelength times a constant. Thus the longer between the bow wave and the stern wave the faster the boat can sail. Accordingly the earlier a boat can create a bow wave the faster she can sail. That’s why yacht designers give fast boats, boats that travel at a high Froude number a high prismatic coefficient – the prismatic coefficient is how many % of the underwater hull is left after you shaped a prism with the boats midsection and its waterline length. A high prismatic means full end, the opposite of wave piercing. Common numbers for sailing yachts is 0.54 % powerful powerboats more towards 0.7 %

The ocean sailing yacht may not have such a high average speed but out on the ocean there are big waves and in the trough, sailing downwind, there is a counter current often 2 to 3 knots fast if you add that speed to the average speed you are in a high Froude number speed range and need a high prismatic not wave piercing bow.

One more thing sailing fast down a wave and meeting a counter current is to ask for a broach. A spoon bow reduces the risk of broaching.

Further a spoon bow increases a boats initial stability as it makes the boat wider in the bow than the wave piercing bow and it’s the beam integrated over the length of the boat that is the initial stability.

Below two illustrations

A boat at hull speed. The bow wave and stern wave have created trough in wich the displacement boat is trapped.
The spoon bow of Exlex Minor

To be continued…

Regards Yrvind

MORE SHAPING

Today, besides running I have been using the long board on Exlex. The result is hardly noticebel   but I include a photo anywhy.

Also I have been on the phone trying to organize the lamination.

Me and Exlex Minor

To be continued…

Regards Yrvind