Wednesday, May 02, 2007

Even closer..

Forgot to bring my camera today, hence no shots "under way". I started out with glueing in the two carbon half pipes under a layer of tape . I didn't vacuum this as I was afraid that the procedure might have deformed the tubes and not left enough room inside to tread the rope:

Here is a close up of the two half tubes attached to the sides. There will be a net between these in order to keep the cargo relatively dry. A positive side effect is that these profiles will make the hull side stiffer in this area, which is the lower part of the float and the part immersed most of the time. Hopefully this will restrain "pumping" and underpressure in this compartment which will lead to it being less susceptible to water penetration (via hatch):

At the same time I set up for a new infusion of carbon tube for the other float. This time I dropped the wax (which prooved to have no effect on the first tube) and instead I laid a layer of release film closest to the mold tube. Here you see (from inner to outer) release film - bi ax carbon (500g) - peel ply - release film - RDM - vacuum bag. The resin has been infused, inlet closed, still tweaking out excess resin from each side:

Time will show wether this set up works......

Then I started shaping the keel on the starboard float. I made MDF-board patterns with different radiii (one of wich is shown down right) and shape the hull at several locations with grinding paper. When all these locations are done I will use the long board to "fuse" these radii.

Tomorrow morning I will start a two day road trip to our capitol Oslo. The purpose is to bring home a lot of epoxy, carbon, foam, RDM, microbaloons etc etc. And maybe have a sail on "Frimann" if the wind is up (not worth while until mid teens).


Bill said...

Great site, Tor. I noticed you say the carbon/Kevlar hybrid fabric is better for the outside than inside. In fact, since you are building a sandwich, the inner skin is in tension and the outer in compression, so Kevlar is best on the inside. But maybe you know this already since you're obviously using the hybrid fabric on the inside. Should be indestructible!

Tor Rabe said...

Thank you, Bill!

You are right, of course. But there are more factors to be taken into consideration. The inner side will be subject to compression where the bulkheads meet the skin, thus I have a strip of carbon in those zones. Also, carbon is as good as kevlar/aramid in tension, far better in compression but far poorer with respect to direct trauma and general wear.

The main hull will be built with pure carbon on the inside and carbon covered with hybrid on the outside. Hope it will withstand some rough handling...