February 26 2004

Resin Infusion...

I have completed a series of 3 resin infusion tests., progressively larger, as many others have done. For my flat panels, it seems a lot of work for what benefice? With infusion, it is complicated, if not impossible, to laminate both faces of a foam panel in one operation. You have to bag one side, cure it, flip over and do it again. I have to build 13 4' x 24' flat panels for my scarab so that makes 26 bagging/infusion jobs: crazy, knowing that a F39 builder makes the outside skin on a float in one shot!.

I think flat, horizontal panels are faster to make with traditional vacuum bagging techniques, laminating both sides at once on a flat table. I made a couple panels like that and it works and is quick. You can also use the same bag many times. That is the method I will use for all my panels. I am starting to think that unless you can buy pre-made panels (a la Duflex or plywood), it is a lot of work to make a hard chine boat... There has got to be a better way. In any case, I will keep track of my actual boatbuilding hours.

Beam Finite Element Analysis

I have completed my optimisation of the scarab22 cross beams using finite element method. I ran a few different models, iterating between less weight or more stiffness, while staying as faithfull to the original design as possible. I ended-up with a weight reduction of 5% with a stiffness increase of 20%. Not bad. I could do better if I was starting with a blank sheet of paper... and if I had more time!