Taking the re-sheathing thoughts a step further,
I've been involved in building and restoring narrow gauge freight cars and another thing that works well is to pre-treat the edges that mate when the sheathing is nailed on the car. As SP noted, treating/painting them before installation is easy. Use a primer that color matches the top coat so when the wood dries and shrinks on the car (which it will), the reveal does not have some light colored paint showing through. This way you have a well sealed car with sheathing that retains a good appearance longer.
We also applied boiled linseed oil to the sills, stringers, needle beams and the bottom of the wall studs prior to nailing the sheathing on. The oil makes a good water barrier for structural members in the car's frame.
Stewart
Edited 1 time(s). Last edit at 02/25/2014 01:33PM by Stewart Rhine.