I used Coosa for a transom on an 18' starcraft Starchief. If you decide to go that way I can probably give you some suggestions about how to use it. Short story, it is light and will never rot, works nicely, but is expensive and hard to source unless you are near a supplier. You would probably have to buy a whole sheet, but might have some left for other things. For a small boat you may want to use a very good grade of Marine ply and seal it well and it will likely outlast you.
Very nice project and you will take to rivets easily with your experience. They are a joy to put in unless you have touchy neighbors close by.
Ron
hey thanks guys, I'm going to keep it as original as possible with only minor modification. I am an aluminum boat builder by trade but have never dealt with a riveted hull. All boats I build are welded. I'll have to make some decisions on rebuilding the transom to begin with. im considering building an aluminum plate with internal structure for the aft and interior sections that have rotted away. the other option im looking at is coosa board.
