Posted by Jim on December 21, 1998 at 10:06:28:
In Reply to: Need advice-Squirt handling problems posted by Don Fisher on December 14, 1998 at 07:20:16:
Can't help with the sliding problem, but...
Last Summer I received some good advice on the restoration of an old Glasspar G-3 fiberglass skiboat. There was a lot of emphasis on shaping the bottom to prevent porpoising.
They say the bottom needs to be PERFECTLY flat longitudinally from the transom to where the natural curve starts. This is accomplished by laying a good straightedge parallel to the keel and at many distances from the keel. You mark the low spots, where the edge fails to meet the bottom. When you're done, you connect the dots and end up with what looks like contour lines on a map. These will be your guide to filling in the low areas (probably don't want to remove high areas!).
Another point, which Glen-L also emphasizes, is that the "corner" where the bottom meets the transom must be sharp, not radiused. Somewhere on this website I've seen their method for wrapping a sharp edge with fiberglass.