My limited knowledge and research on the subject tells me it's been done and some say it's ok and others say it's not. Various reasons for their opinions. I KNOW for a transom it's been done with good results but for a hull I'm just not sure. I'm not a PRO so I don't KNOW!!!! I'd advise you to do a LOT of Googling and Searching on End Grain Balsa Core Repairs and see what you come up with and then draw your own conclusions. I will continue my searching as well and keep you informed on what I find.
Here's what one guy said...Should work... assuming its pretty flat.... you will have a hard time bending it otherwise.. the key to success will be that you:
1. coat ALL surfaces of each strip with epoxy to make them waterproof - you dont want the rot again (waterproof glued wood can still rot if wet, warm with a bit of O2)
2. fill ANY gaps between the strips with an epoxy putty that is designed to work with the epoxy you use - this not only adds some strength, but stops any water from getting around that might get in there
3. if you make any holes, for fasteners for example, in this part (or any part) of the hull, first seal them with epoxy before putting the screw in, and use some bedding around the head for extra protection
4. put a layer of fiberglass in, soak it with epoxy, and then put the strips on top... don't just lay the strips ontop of a layer of epoxy.
5. roughen up the old surface first
This should help. But do note that the plywood will be heavier, and if you use a lot it could affect the balance of your boat. Also, its stiffer, so if its pounded a lot, the laminate layer might crack, or separate from the ply... but that would require some pretty extream multiple stress...
