by Bogo » Thu Oct 25, 2012 8:20 pm
Live oak, but it ain't cheap and it is in short supply. You'll have to fight ship restorers for it. Is it needed, no.
Be very careful of the design. Where the stresses will be greatest is where the protective surface finish will fail first. Look to minimize point stresses, or even using an alternate material that can handle the stresses without failure. This minimizing of point stresses can be very important. Take the tongue. It is foolhardy to have it be part of the main structure of the trailer. Where it connects to the rest, it and the main structure will always be flexing. It should be a separate part that is separately finished. Design high stress parts so they can be replaced. Then finish them as a separate part, and finally install them after finishing. When they are refinished, separate them and refinish them separately.
A real important thing is ALL wood structures require routine maintenance. I'd put a wood TD trailer close to a small wood boat in maintenance requirements. If left outside, all stressed areas and wear surfaces should be refinished every year or two and more often if they show wear. Parking it inside only delays the inevitable maintenance. This doesn't just mean slapping on a new coat of paint or varnish. Remove the metal frame from the wood, and refinish the whole surface of the wood, not just what is visible. Where the wood meats metal there will be differences in expansion and contraction as well as stress. That will likely be enough to crack even the best finishes. A thing to note, a metal piece, like door hinge, that is well beaded with a quality caulk is really two joints with a flexible piece between them. That can last allot longer, but every so often it still needs to be pulled apart and redone. The caulk provides cushioning, as well as it keeps water from making its way to any cracks under it. Cracks that extend out from under the caulk will still be able to wick water into the wood. The caulk just reduces how often the parts need to be pulled apart and fully refinished. Refinishing the exposed surfaces still needs to be done.
It's been a long time since I've maintained a wood boat, so I likely have forgotten allot. Reading up on wooden boat design and maintenance would be good for anybody using an all wood or primarily wood structure. Even the most rot resistant woods need protection and maintenance.
Thinking about parking it inside. I used to have a large storage locker that would have been perfect for a TD. Nice grade level access, and wide enough to easily move a TD in and out.