Somewhere between a Deep V hull and a Bolger Advanced Sharpie

 
Johannes
 
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Johannes
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17 December 2013 06:37
 

Today I am having fun with a needle and thread. I am making a Wharram Soft Wingsail for my new steel proa.
It has 230% larger area compared to my crab claw sail (which rests on the bottom of lake Mjörn)
140 cm high, 48 cm deep.

I have to make a jib too, so it will take some time….

Cheers,
Johannes

 
 
Johannes
 
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Johannes
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19 December 2013 02:28
 

I don´t have enough sail-cloth for a jib or genoa at the moment, so I will test it with only the main Wharram soft wing/gaff sail.
This is the first time I create a gaff sail soo I hope I get it right. As usual I try to make it as simple as possible.
I want to sail my model now, not concentrate on every possible little detail.
I want to test the wide slot between the jib and the main sail Russell talks about. I want to see what kind of upwind performance I can get from my simple hull shape and heavy steel construction.
I am no sail maker soo there is probably a lot of details that is wrong or could be much better.
I will test it within a hour or soo. I hope I can make a video of it sailing.

Cheers,
Johannes

 
 
Johannes
 
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Johannes
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19 December 2013 04:14
 

I test sailed my proa and I am impressed by it. Even though I can not adjust the sail to get the most power and my rudder was a ragged piece of 1/4 inch plywood I broke of from an old horn-loudpeaker (I forgot my rudder at home), it was fast. It accelerated quite slowly but it just kept on going faster and faster as long as I could keep the retrieval line out of the water.
It was hard to balance the boat, as the rudder was really bad and there was only a mainsail with the CoE far aft.
I will buy some more spinnaker cloth and make myself a jib soon.

Cheers,
Johannes

[ Edited: 19 December 2013 04:29 by Johannes]
 
 
Johannes
 
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Johannes
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28 February 2014 04:50
 

Steel Proa sailing slow motion - Youtube

I have painted my steel Vaka in high gloss black on the outside, and some rust-like red/brown on the inside.
i have a short clip of my proa sailing. I had to use a scrap piece of plywood as a rudder, so it does not sail straight.

Cheers
Johannes

[ Edited: 28 February 2014 04:52 by Johannes]
 
 
Tom
 
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Tom
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28 February 2014 14:20
 

I’d love to see that full speed Johannes.  Looks like you need to get the ends decked 😊

 
 
Johannes
 
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Johannes
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10 May 2014 13:21
 

My kids trying to destroy my steel vaka - Youtube

We had a fun afternoon of destruction and vaka-abuse.

After throwing the steel vaka 6 times down the slope, banging it repeatedly to the ground, throwing rocks at it and blowing up fireworks underneath it it still floats.

This is why I prefer steel in cruising boats. Steel will take abuse that would turn a carbon/fiberglass/plywood boat into splinters.

Cheers,
Johannes

 
 
Johannes
 
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Johannes
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11 May 2014 03:04
 

Kill kill kill!!!

A short clip of me beating the vaka against a rock. I am very impressed by the strength of 1,5 mm cold rolled steel welded by a total noob (me) with cheap 6013 electrodes, too little current and cold welds.
When I tried this with some 12 mm plywood it shattered immediately.

Cheers,
Johannes

 
 
Johannes
 
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Johannes
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11 May 2014 08:47
 

One minute of destruction - Youtube

One hour of destruction filmed in 8 minutes and speeded up to one finale high-density minute of destruction.

This might seem like a waste of time, effort, bandwidth and whatever, but I do think one learns a lot by trying to break something. A plywood hull did not make it through the first crash on the rock. The steelhull looks like sh_t but still floats. I learn that the first thing to go is the welds, and that steel will take abuse without any problem.

I know that structural strength does not scale linearly, but the difference between plywood and steel will be the same - regardless of scale.

Johannes

 
 
Editor
 
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Editor
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12 May 2014 21:11
 

There is a metal boat named “Mithril” in my local harbor. Seems appropriate.

 
 
tdem
 
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tdem
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13 May 2014 01:52
 

A few days ago I visited a 50m steel superyacht under construction. The boat was actually almost completed a couple of years ago, but there was a massive fire which burnt out most of the inside, and melted the aluminium superstructure. The steel deck was quite distorted in most places, but structurally it was still good. Only steel could survive something like that.

 
 
Johannes
 
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Johannes
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15 May 2014 23:35
 

Every time i see the word “mithril” i think about Titanium. Stronger then steel, but still lighter. Expensive, and in the words of Gandalf “but the beauty of mithril did not tarnish or grow dim”. Titanium does not oxidize in air. Once polished it does look like silver. My father had a piece of titanium on his desk when i was a kid. I often played with it, and often commented on the shine and the stiffness and apparent strength.

Johannes.