Re: Floor in a Bayliner.
TR, Slow down a bit! I wouldn't go ripping out the entire inner layup just yet. Many hulls are built with a core material. Several materials can be used, basla, plywood or airex foam for a few examples. Generally what you have when building a fiberglass boat hull in a mold is the outer layup, the core, and the inner layup. What your situation sounds like is an area where the bond between the balsa core and the inner layup has delaminated. The fiberglass may have cracked due to excessive flexing because of poor bond with the core. There may be a recovery from this, depending on the extent of the delamination, short of removing the entire inner surface of the hull! First of all, is the core material rotted? Is it wet, darkly discolored and/or crumbling? If not, you might only have to chase the delamination, rather than major surgury. Tapping lightly on the inside of the hull could give you some idea of the extent of the delam. When removing the delaminated area, I would recommend grinding (sorry about the itchy dust) out the area so that you don't inadvertantly spread the delamination farther than necessary. What may have happened is that the manufacturer did not properly hotcoat the balsa surface prior to doing the inside layup. If you don't hotcoat the core before layup, it can suck the resin out of the layup, especially end grain balsa( the stuff is like a sponge). <br /><br />I"ll try to answer your questions the best I can.<br /><br />Why is the wood in there? - The wood is there to add greater strength and rigidity to the hull, it won't tend to flex as much.<br /><br />Why would it be made up of all of the small end cuts of wood? - The balsa is cut into approx 2 inch squares and has a cloth netting adhered to one side so that you can can use it on a curved surface and it will lay flat. The reason they use the end grain is because the balsa is stronger in compression that way. If it was made using an edge grain it would be more likely to crush under load. They also use balsa because it is lightweight.<br /><br />Can I use something else? - Yes you can use something else. There are several materials you can use. I confess that my knowledge is somewhat dated since I haven't built boats professionally for some time, but we used to use balsa, plywood and/or airex foam sheets. Plywood was usually put in relatively flat areas (it doesn't bend into curved areas very well) where we wanted superior strength. Balsa was generally used where we wanted additional strength but in curved sections. Airex foam sheets were used primarily in higher end hull construction, not in decks due to deck temperature concerns in tropical sunlight.<br /><br />I'll be interested to see how you make out, it can't be as bad as you think! You did not say what year or model your Bayliner is. Hope this helps, Good luck
