Roger gave me this boat for an afternoon. I had a wonderful time. I wish I had one. My 12′ tri design with a lot of Roger’s updates in it.  It has speeds like on a bicycle.

I have an ancient Universal Plastics catalog. It is full of all the data on every kind of plastic. They are now called Laird Plastics and the catalog now is only online. But they still sell everything plastic. 60 locations in US and Canada.

http://www.lairdplastics.com/

The mast on my Geko was 60′. When Haiko bought that boat, the mast had to go into the container. Haiko is a master machinist, so I watched him do it. He recently topped up my recollection with the procedure.

“As you said: the mast was indeed welded together from 2 pieces. It was done with 2 inner-plates made from the same mast profile on port and starboard.  By sanding the paint you could see the different structure of the welded aluminum.
Three rows of holes measuring about 3/4 of an inch were drilled in the outer profiles and to the welded  plates.
So we had to drill holes of 30 mm through and  around them as the weld is always bigger than the initial hole if done properly.
The mast was cut very attentive (carefully) 3 mm under the weld, to know sure it would part while trying not to touch the inner-plates.
Back in Holland 3 different series of props (nuts? I will find out)where milled 3d for inside as well as for outside.
After welding we still had to do some sanding on the inside. The mast is now demountable in two parts for legal transportation on the road.”

Although only 55′ long, Palmetto Breeze operating out of Charleston SC is certified for 100 passengers. It looks close to the limit in tis picture. Teambuilding was never so much fun. CM plywood/epoxy.

One thing Alex reminded me was that he has gotten many of his LED lights at bargain prices (like $2 each) from the Imtra website clearance items tab. http://www.imtra.com/lighting.htm
And don’t forget Craigslist he would also remind.

I got to visit Alex again last weekend as he nears launch. Recall he is building a KHSD 45 with aeroesque rig. Some close-ups of the rig.

By now every boat builder knows that fiber orientation is critical to laminate strength.  And I’m sure everybody knows that 34 oz triaxial for example has a bending strength of some 65,000 psi in the 0 degree, and about 20,000 psi in the 90 degree orientation, hand layup. And unidirectional fabric will have some 100,000 psi bending in the 0 degree and maybe 3,000 psi in the 90 degree.

But that is not all there is to it.  There has to be off axis fiber even if it performs less well.  I first learned about that in Tsai’s composites class in ’90 I think it was.  In tension it would not matter, but in compression and bending, the hard-working 0 degree fibers have to be kept in column, as it were.  The trick is to  have no more than 3 zero degree layers stacked before adding an off axis one.  Then you can add three more.

I have visited mulithull build sites where I have seen plans from famous designers with like, 10 or 20 layers of 0 degree stacked up, and no off axis fibers.  Don’t they know?  And they charge many times what I do.

One of my builders (37″ cat & 43′ cat) Jon Reed has put a boat anthem on the U-Tubes.  He has great earlier work also.

http://youtu.be/-8c4h7zH7z0

They got this http://www.bravoyourcity.com/microguide/san-francisco-family-getaway

They have two KHSD charter cats, a 55′ and a 65′.

I had rare good weather to mix epoxy. Supposed to rain next week so will be back in. I have thought of many topics for here for the coming week.
Fiber orientation update
Fiber mix examples
Taking a mast joint apart
Upgrading bad details from other designs
Psychology and window shapes

See, I think when I am stirring epoxy.