by Ray » Wed Oct 06, 2010 1:29 pm
From a good boat repairman:
Plywood is stronger than foam in most cases. So long as the fasteners are bedded properly, you won't have leakage. Core leakage is one of those things that happens purely because of neglect. Neglect at the time of installation, as well as neglect during the life of the fastener due to owners not monitoring the vessel. What's more, if the fastener hole is fully bedded with resin, you can't hurt the core even if the fastener leaks, and again this is not difficult or costly to do.
For us to give up on coring, means we have to give up on the entire possibility of a boat being built as specified. If that is true, then the whole thing is suspect, right down to the laminate. Now, given the fantstic laminate failings we have seen with Bertram and coring silliness from Searay, as consumers maybe we can't rely on specifications at all. But as boatbuilders, I think we surely would be able to take full accountability for quality control. One has to wonder whether coring issues are actually ignored or engineered because they are not difficult to avoid. For some reason its just not a priority.
I admit that I like solid glass box stringers formed over a foam core because there is simply no way to hurt them, even if you saturate the foam core (yes most foam cores will suffer from water adsorption). I like it because I don't have to trust someone elses ability (or do I? how do I know they didn't screw up the layup of the glass if we can't trust them to do something as simple as sealing wood?).
But if you want to build the strongest boat at one of the lightest weights, at the lowest cost then you almost certainly want to use wood. What's more, it is NOT difficult to seal a wood core. So, again I say that if the boat is built well, we have no standing whatsoever to blame the wood as a failure point. We should be blaming QC, but we don't, we blame the material.