Waffle I don't totally disagree. It just depends
Where and when you use closed cell foam (or even better Honeycomb) and where you use end grain balsa. I totally agree that in the old days of boat building they used marine plywood and over the years we have learned that end grain balsa is much better as it does not allow water to migrate horizontally. If I had all the money in the world I would probably have a Honeycomb composite for the hull if I made sure it was meticulously built with full epoxy through hull openings. It has been seen that the deck core foam has shown more compression defects over time. Yes its better than plywood for wood rot, but not nearly as good as end grain balsa for compression stability which turn out to be a bigger issues on decks over time. As this site says " Balsa has a lot of advantages that foam does not. For example, because of the exposed end grain, when you coat it with resin, the wood cells suck up that resin via the capillary effect and makes for an extraordinarily strong bond. It does not require any special adhesives as many, if not most, foams do." And there is more - like I said it really depends. So just saying foam is better is not necesarilly qualified. Remember - It depends He even make the argument "So it is that we end up with problems like this in foam cored boats that almost never appeared with balsa cored boats. Instead of making a boat better, it made it worse. http://www.yachtsurvey.com/core_materials.htm This guy goes so far as asking the question "Should Hulls Be Cored Below Waterline?" And then answers the question " I don't hesitate for a moment in saying no. Not with any kind of material. The risk is too high that something will go wrong, mistakes either by the builder, the owners of the boat, or someone working on " For extra reading and more perspective Here is some fun late night insomnia reading
http://www.balsasales.co.uk/ http://www.corecomposites.com/balsa.cfm?family_id=2 http://www.jcrocket.com/bulkheadtest.shtml
Where and when you use closed cell foam (or even better Honeycomb) and where you use end grain balsa. I totally agree that in the old days of boat building they used marine plywood and over the years we have learned that end grain balsa is much better as it does not allow water to migrate horizontally. If I had all the money in the world I would probably have a Honeycomb composite for the hull if I made sure it was meticulously built with full epoxy through hull openings. It has been seen that the deck core foam has shown more compression defects over time. Yes its better than plywood for wood rot, but not nearly as good as end grain balsa for compression stability which turn out to be a bigger issues on decks over time. As this site says " Balsa has a lot of advantages that foam does not. For example, because of the exposed end grain, when you coat it with resin, the wood cells suck up that resin via the capillary effect and makes for an extraordinarily strong bond. It does not require any special adhesives as many, if not most, foams do." And there is more - like I said it really depends. So just saying foam is better is not necesarilly qualified. Remember - It depends He even make the argument "So it is that we end up with problems like this in foam cored boats that almost never appeared with balsa cored boats. Instead of making a boat better, it made it worse. http://www.yachtsurvey.com/core_materials.htm This guy goes so far as asking the question "Should Hulls Be Cored Below Waterline?" And then answers the question " I don't hesitate for a moment in saying no. Not with any kind of material. The risk is too high that something will go wrong, mistakes either by the builder, the owners of the boat, or someone working on " For extra reading and more perspective Here is some fun late night insomnia reading
http://www.balsasales.co.uk/ http://www.corecomposites.com/balsa.cfm?family_id=2 http://www.jcrocket.com/bulkheadtest.shtml
