Transom rebuild

[CATmech945]

I have some general questions about rebuilding a transom. I've looked into a few different materials for rebuilding it and I'm probably going to go with the #26 Coosa. I'm just not sure what thickness material to get. The boat is 23ft and currently has a 200 hanging on it with an armstrong bracket. I'm planning to repower the boat at some point with a 225 or 250, maybe twin 115's. The current H.P. rating is 230 and the transom is 1 1/5 thick marine ply I think. Probably two 3/4 pieces laminated together I would assume. I guess my question is, if I'm planning on increasing the H.P. of the engine at some point, should I go with a 2 inch piece of coosa or would 1 1/5 be okay. They don't sell anything in between. I would rather go a little overboard with the build but the cost difference between 1 1/5 and 2 inch is pretty substantial. Any input would be greatly appreciated. I'll post some pics once I get started with this nightmare so ya'll can tell me if I'm screwing the pooch at any point. Thanks in advance!!

Aaron

[1987196]

I would say that the 1 1/5 would be fine, but I would bulk up the glass with a core mat.  When i just pulled my transom there was only 2 layers of glass laminating the transom core, one woven one chopped mat.  when I put it back I an going to bulk it with core mat, the core mat makes the stronger and lighter than straight glass.

[Capt Matt]

11/2" bluewater 26
Capt Matt

[dirtwheelsfl]

i would vote no on the coremat. all it really does it build up thickness in the laminate, doesnt make it stronger. not to mention it sucks up enough resin to wet out probably 2 layers of equal size 1708. th stuff will actually compress under load, even with glass on both sides. and if its not wet out enough, it ends up a real weak bond. id stick with straight biaxial glass...

[1987196]

Coremat is meant to build thickness and to compress, just like any other core material.  The engineering behind putting a core in any glass is to create a space between the layers of glass therefore allowing one layer of glass to flex seprately from the other.  This adds strength because the layers of glass when flexed are not trying to shear from each other.  And it does add bulk.

[CATmech945]

Thanks for all the replies. Capt. Matt, did you use 2'' #26 on your transom?