|
did some more playing around with fiberglass today. I made a sheet with three layers of 1oz/sq ft csm which is equivalent to two of the 1.5oz (450g), and one with 1/4" of polyisocyanurate foam sandwiched between two layers of 6oz cloth. the foam sandwich is stiffer, but it delaminated too easily. the foam failed under stress. the csm took more stress and returned to it's original flat shape. I think the polyiso foam is not as good as extruded polystyrene, but I don't want to have to buy epoxy if I don't have to. also the weight difference was minimal. I am working on plug #2 the left side. which will be a mirror image of the right.
on the issue of shape and using contours to add strength, I feel that any contours I add would negatively affect the aerodynamics of the fairing. the best shape is a very simple one. and should not be compromised for aesthetics, or even to increase rigidity. I can add ribs for that.
|