The wood frame double-hung windows I installed about 9 years ago are now suffering damage from condensation. I know I need to address the problem of condensation, but what can I do about the wood frames of the windows? They are black from moisture damage. I tried removing them and sanding them down and repainting with a mildew-resistant additive in the paint, but it’s not sticking very well and I’m afraid I’m back to square one. Is it possible to at least replace the narrow wooden pieces that hold the glass in place? I can make those myself using the old ones as a pattern. Will it harm the window if I replace them? They look to be stapled in place.
after sanding away as much as you can, dampen a cloth with some bleach water, not much at all, and wipe it down, then sand again with a fine grit paper. repeat this process a few times then try painting once it is dry.
Also you can replace the narrow wood pieces, those just hold the glass in the sash. be careful if you remove all four at the same time, the glass might fall out.