Denny Anspach <danspach@...>
I could not agree more on the profound benefits of stability that the sealing of ALL free surfaces of wood or paper exposed to air -in or out- will bestow on any model. If you value your modeling, and modeling efforts, there is simply no reason not to do it .
I personally draw from an old bottle of Testor's Hot Fuel Proof Sanding Sealer (essentially talc in clear lacquer). This fills the grain nicely, dries instantly, and is very easily sanded smooth. These types of sanding sealers are still commonly available at R/C and other hobby stores. Paint alone if applied thick enough will also be a good filler, but too often, a single paint application will not adequately fill .
All wood and paper exposed to air WILL move with changes in moisture, and if one surface of either is sealed - relatively- with paint, or is restrained by being glued to another piece, then the other side will be the only part free to expand or contract, forcing the piece to bend (warp) one way or another. Some woods will behave worse than others in this regard, Pasteboard, and other cheap papers are the worst of all.
In my occasional other life of restoring ancient paper/wood HO freight and passenger cars, I run across this problem all the time. I use a number of methods to try to solve it, including heat, replacement, or reinforcement, with or without mechanical stiffening. I never put them back together, however, without first sealing every bit of paper or wood that will not be painted or supported- in or out.
Denny S. Anspach MD