Transom Support

I have a 22 inboard and I am in the process of installing a 9.9 auxillary engine(90 lbs) on a new garelick outboard 4 stroke bracket. The bracket is very beefy but I was hoping for some input on the ability of the transom to handle the stress. The boat is a 79 chris craft CC so it is well built, The transom has a convex shape and at a slight angle and is 3/8 - 1/2 solid glass - no core. Since the boat has much needed trim tabs, the bracket is going to have to be mounted near the center which has a little more flex than I thought it would. The inside of the transom is easily accessible by removing the fuel tank so I want to beef up the transom with half sheet of 3/4 ply wood. I was going to use WEST epoxy with a 406 filler to bond the plywood to the glass and then laminate it with some WR. I was going to use some knee braces to bond it to the hull bottom for strength.

Any thoughts on how much support I need and what steps to follow? Is this overkill?

Thanks for any help you can provide.

James

 

sounds like you have a good handle on the situation.

 

Yup, why would it be overkill? Most ways of doing it will cost you the same in effort, so why not do it properly, in the fashion you, yourself suggested? Even if it does become stiffer than is strictly necessary, that can never be a bad thing, imo. That way even a bit of rot down the line won't take you over the line of breakage.

I'm no "real" boatdesigner/naval architect or what have we, but if the effort is the same, why not make it as strong as possible.