One of the best sailing mags there is, now available for download.

Course I’m prejudiced as Richard, the editor sails the hell out of one of my 63′ cats and has done so for years.

http://www.latitude38.com/ebooks.html#.Uaj2I9KsiSp

I see that the link on my earlier entry on X-Bows no longer works. So the link again, and another from Vigor.
http://www.youtube.com/watch?v=GJsogw9fHE0&NR=1&feature=endscreen

and

http://www.youtube.com/watch?v=H0w8AktIkCo

For the Hardware, the website is www.BlockandWInch.com . For any of your customers I would create a coupon code which would give them about 20% extra discount on the website prices, which should beat any prices worldwide especially on the winches.

Many thanks

Andy  sales@blockandwinch.com

Hi Kurt
Know anyone who may be interested in any of this?

Mast Isomat Ng31 40.5 ft
boom Isomat Nb16 10.5 ft
mast 2.5 x 3.5 23 ft
boom 2.5 x 2.75 10.5 ft
Mast extrusion 6.5 x 5 35.5 ft
same 17 ft

Stiletto cat main sail
blade jib (tube cat 30)

Location Keswick, Ontario

ontact Don at   don@thornhill-canada.ca

I finally tracked down the book I needed to verify the design rules for the 149′ passenger trimaran. It’s the IMO HSC Code 2000. I faced the expense and the month wait for it to be posted from UK. Then I saw on the IMO website that their publications are also available at Captain’s here in Seattle. www.captainsnautical.com  I had forgotten that they have everything to do with boats there. They are now carrying my Design Book also. (and at less cost as there is no shipping cost)

Maybe once a week I hear a suggestion that someone wants to slightly punch up a glass laminate with a bit of carbon. Or even a bit of Kevlar. I have even seen laminates on a roll with a small bit of carbon mixed in with the largely glass roll.  It is seen like a vitamin I guess.
Bad news,  it doesn’t work that way. The problem is the difference between each material’s stretch to failure percentage. E-glass is around 6%. Carbon is typically around1%. So, for example, if you had half of each in a laminate, when the carbon started to fail, the e-glass would be only contributing some 17% of its possible strength. Another way I have heard to visualize this is to imagine two boards several feet apart. A steel wire, and a rubber band connect them to each other. Imagine that each will fail at 100 lbs pull. The rubber band is doing nothing yet, as the steel fails and breaks.

E-glass can be laminated with carbon, if they are not both oriented in the zero degree axis for example.  The carbon could be on the 0 degree and e-glass could be on the off axis.  The off axis will contribute almost nothing to the strength, but will help keep the zeros in column and add some shock absorbing ability to the laminate.

Just back from Home Depot where I tried to find something called Roofers Sticky Tape. No joy. They had never heard of it and did not have it. I find it on a note from last IBEX, maybe from Jim Gardiner? By the name, it sounds ideal. I imagined some nasty, black, cheap, industrial sealer on a roll.
I did get some Scotch Indoor Mounting Tape for $10. 350 inches. So far nothing seems to beat Liquid Nails Projects, at under $2 a tube. Most baggings take just over one tube and the excess in the opened tube keeps until next time.
Anybody has any more on the Roofers Sticky Tape, let me know.

The new ProBoat Drawing Board picked a first design right out of Stuff Done Wrong. Yikes!
http://www.proboat.com/proboat-drawing-board
A 36’+ powercat that is only 12.6 feet wide overall. It takes me right back to the Florida cat rolling over in the relatively small beam-on wave and killing someone. Yikes. http://multihullblog.com/2013/02/catamarans-and-waves/

And it seems to be over 20,000 lbs. in lightship condition.  For a 36′ powercat.  Yikes. No wonder it needs so much horsepower. We are supposed to be improving these things.

 At least once or twice a week I am approached by someone who wants to have one of my composite cats done in aluminum. Usually they don’t care that the result will be up to 50% heavier, have more complicated interior, and have no insulation, compared to a composite one.
They like the idea that they can hit a rock and presumably not have to stop. There are a couple of assumptions in the mix that are usually not noted.
For whatever reason, alum. cats are usually done by fishboat builders. Fair and smooth is not even a concept, compared to what efficient catamarans must have. I recall hearing that Atlantic Fury was up to 3/4″ out in places.

For fishboats, that’s no big. They just pile on the horsepower to make up for it. With a rough bottom like that, driving around with rock damage is not an issue.  If the boat didn’t sink, nobody cares.  Until they have to pay for the fuel.

Again, for any cat to move well, it must not only be light, but also be extremely fair and smooth.  It doesn’t matter if it’s composite or aluminum, a gouge will slow the boat down and require more fuel.  And any unrepaired gouge will attract marine growth and further slow it down.  And again, the fishboat guys don’t care about efficiency.  We do.  The word catamaran means something very different to a fishboat builder, compared to a design that moves well.  The work-around for fishboat builders is to basically bog up a composite hull on the outside of the aluminum hull to make it fair enough.  But even with that is done, if the idea is that you can crash aluminum and not have to repair it is followed, you will be reducing that efficiency.

And always I wonder, if you have an aluminum cat with an added composite hull outside, and basically a composite hull inside to insulate it,  why the alumimum again?

In summary, smooth and fair are important for catamarans, but are often forgotten in building aluminum ones.  And don’t forget that there have been big advances in impact resistance of composite hulls compared to the polyester ones of 30 years ago.

I wasn’t gone. All last week, in fact since the last post, every time I tried to log onto this blog I got the message “access denied”. I see it’s finally fixed. I will have some posts shortly. I do have a couple of USCG emergencies today and tomorrow.