Category Archives: Projects

Building power cat hulls

I took on the job of building a set of hulls for Kurts 28’ power cat design which we stretched to 31’ by adding about 2.5 inches to every station. We upped the stringer size by 30% and glassed with 8oz rather than 6oz but otherwise stuck with the plan and laminate schedule. We used multiple layers of 8 and 10oz to make up biax tapes, i find it makes for easier fairing and allows for tapering the buildup. We did a half-way-to-yacht quality fairing job, primed with 545 and installed cleats, hatches, fuel tanks, and fuel fills. There will be lightweight 25 hp engines mounted on rear transoms. We finished both hulls and shipped to the owner in maine, who is going to build the cross arms and center cockpit over the winter. I really can’t recommend committing to building a boat over the summer in sarasota, florida in a non-airconditioned space, but, in the spirit of running a marathon, and other ridiculously painful ways to enjoy yourself, we did it.  Total build time, including purchasing, hardware, and mounting on a trailer for shipment, was in the neighborhood of a thousand hours. LOTS of pictures after the break-

Stringers

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GPO-3

I got the GPO-3 fiberglass sheet from Online Metals dot com. I hoped to substitute it for the more expensive G-10. Looks like it worked. It is smooth like G-10 though in the picture above it looks rough.
This 2 foot by 2 foot sheet was $10.  Picked it up myself.  Compare to same size G-10 at McMaster Carr at $47 plus some $20 shipping.
The red probably means it is phenolic.  Both of these are fire resistant.

The panel looks like it was made with chopper gun, but it will be used for low load applications, so no worry.
They did used to be a friendly neighborhood supplier. They have been bought by Thyssen Krupp and have a new corporate bureaucracy feel now. Good prices though.

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65 Charter Cats Front View

I got that great opportunity to see my Alii Nui side by side with a Constant Camber 65 last week. It was great to see the differences. Again, both were built by the same yard. Alii Nui is foam/glass and the CC 65 is constant camber. Except for butting all the plywood sheets instead of scarphs, and bagging the ply to a true mold, instead of itself, this boat’s hulls  were built exactly like the CM system that I have been using for 30 years and that CC has been criticizing for almost as long.  Cool.  Oriented ply sheets.  Stringers instead of mass. Thinner hull skin.  Cool.

Alii Nui is 36′ wide.  I cannot find the CC 65 data online, but I’m guessing it is 30′ or even 32′ wide. That makes a smaller playpen.  First the Alii Nui.  Both from the same distance on the dock.

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