Our home was built in the late 1990's with norco casement windows in wood-clad interior and vinyl exterior. The interior wood was never factory primed. The original owners simply painted one coat of latex (white) on the inside. The tops and bottoms of the casement windows were never painted. They remain bare wood. The inside of the box which houses the casement mechnism when closed was also never painted and remaines bare wood. I'm not sure why any of this happened, but it is the case. 99% of the windows pose no problems for moisture (they seal tightly). A few show through recent painting that some amount of moisure is getting in the housing at the casement mechanism and leaching into the wood (the white paint is slightly discolored). There is no sign of rot. I am not able to replace the dozens of windows I have with new ones, but I would like to mediate the moisture issue. Can I simply paint the exposed wood? Why would this not have been done at the factory? Who would want a bare wood where the metal casement closing mechanism is? What a nuisance that will be to paint inside of (besides the dust and dirt accumulation). If not painting, would a coat of some type of clear poly also do the trick? I am really hating wood clad window right now.