solid wood stringer

Hello all.I have a 1978 glastron CV23. all the wood stringer were rotten. I have removed them, cut them all down.they did a poor job a the factory and the sides were only partway glassed in,,,, when I was working on getting them out, I noticed they were elevated from the hull 1/4 inch.... my question. why do they use plywood,3 layers of 3/4. can I use solid 2x10 and 2x8 instead and glass them down,do they need to be elevated? not touching the hull.should I use foam to elevate? all the places I called around to said u can glass the wood directly to the hull bottom> what about hard spots? SEACAST is poured into the old stringer mold. so wouldnt that be hard at the bottom? I am confused...I only want to do this once.. i did read other threads on this and i get mixed answers from people..

Re: solid wood stringer

Welcome to Iboats Andy. I think the experts here (which i'm not) will tell you that you can make your stringers out of anything you want. If you encase them with glass, the strength of the stringer is coming from the structure of the glass itself. Some are actually hollow or filled with foam. Most people here use a thickened epoxy mixture or an adhesive like PL premium to bond the stringer to the hull and provide the space you need between the hull and the stinger. Everything i have ever read here suggests that you need that space between the hull and the stringer. Seacast, i imagine, while appearing very hard probably has some flex to it. I'm not sure on that. Hope this helps some. Good luck with your project.