I have a 1988 SEA RAY SEVILLE B/R. I have cut out and ground the deck and stringers. I have now made the new stringers from 3/4 luan plywood. It is a low grade brizillian mahogany plywood. I have used it on exterior apps. in the past with good results. It did not rot or seperate. I plan on three layers of overlapping woven tape and a layer of mat. Any problems here?