Whatever modern designed cat you choose is simply not going to be able to take on rocks and sharp objects, fibreglass taking on something harder than itself is a one way contest, so why bother to beef up the boat to "maybe" be tougher on its bottom which in turn dramatically increase the weight which then reduces the options for one person to move it about on the beach. That extra 30 or so kilos is the point at about which my back suddenly starts to object and my legs are no longer able to push weights about. <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />
The weight i added to my port hull is about 2 kilo. Using a very course sand paper i ground off two layers of gel coat that were about 0.40 mm thick each. i laid one layer of s-glass across the bottom which is about 0.20 mm thick before resin is applied. i painted on one coat of epoxy over the corsely sanded bottom, applied fiber-glass, painted another coat of epoxy, squeegee, 2 or 3 coats of epoxy with micro ballones mixed in. I sanded that down to a paintable surface. total epoxy, included that sanded off, amounted to 1.5 liters. weight of micro ballons - to light to measure. weight of fiber-glass...6 ounces per yard (170 grams per meter). Polyurethane paint 1/4 liter.
