Love what you are doing for the beam attachment...I am planning to do something very similar for my F14 Project...nice to see it put into practice. Wonder why it is not a more common solution to the beam to hull attachment issue...seems like the most logical method to get a really stiff connection.

As news or progress happens I'll post stuff. Not involved in the AC Cats but I do have a 3 boat C-Class project in the works, so far we are still playing with hull shapes and doing a little CFD work, haven't touched the wing design yet.

While it can be stiff, it is not the reason I had for doing it. The beam tubes need a lot of plastic around the Aluminium inserts inside the tubes and this shape nicely funnels the powders down there as the mold rotates so both sides of the inserted tube are covered. After molding we bore out the inner plastic a bit to get a perfect fit for the beam tubes, 1 bolt at the ends mounted horizontally holds the tubes in the seats.

Given the constraints of the current draft rule for the AC cats, the C Class project seems to be a lot more interesting, even if less visible.

I guess the Vudu will be even more important, but only time will tell.

I was under the impression that Rotomolding used metal molds...how do these plugs factor into the process? Wouldn't this project have been a perfect candidate for direct milling of a metal mold from CNC? Or are these plugs going to be used to create some type of casting? from which the final mold will be constructed?

Much as the common wisdom says that you need aluminium/or metal molds, they aren't the panacea that many believe them to be....they can pit just like any other mold and then you have to silicon fill the pits to maintain surface finish.
We will be using composite molds with a resin system that has a heat distortion temp that's very close to the molding temp and experience has taught us that those molds should be good for about 600 hulls....if we ever get to that many F12's....I'll be both surprised and delighted :-)

Interesting...What type of resin has a heat distortion temp that high? Or does your particular rotomolding technique use a type of thermo set plastic that works at lower temp? It is very cool that you can side step the expense of Metal molds...Would it be safe to say that the viability of the rotomolding project pivioted on the cost savings of the composite molds VS Metal molds? Hull plug looks awesome....

Seeker, there are epoxy resins specifically designed for high temp use. Typically they require a long hot post cure to temperatures beyond where they will operate.

Just out of curiosity, what kind of working temps does the mold have to funtion at for this type of rotomolding?

Seeker,

it depends on the selected plastic but they can vary anywhere between 150 and 300 degrees C (302 and 572 degrees F) IIRC the Tooling resins I've used for high temp carbon moulds go up to about 220 degrees C (we were cooking to 180 degrees C and 7 atmospheres of pressure).

Example

I found this boat while surfing around the internet. It is rotomolded and looks very similar to f12, except for having more metal than a Honda Civic, lol. You'll see what I mean when you see it. Has very similar sail plan and there may be bits and pieces that translate to f12 boats. Available in France and UK. Built in France where catamaran building is govmnt subsidized to create exports.

http://www.windkart.fr/index.php?lang=en