I would recommend sealing with polyurethane and brushed it on. I also would measure and fit all the wood,then removed and sealed it. If you drill into it after it is sealed and installed I recommend you reseal the area again to keep any moisture out.
Hope this helps!!
〉 Answered on Aug 30th, 2012 by Amanda J. Pierce, MBA "AJ", Certified Mechanic, Project Coordinator; Primavera Scheduler at VIGOR Alaska Industrial Shipyard & BizzM3ch Solutions