Our wood windows are not vinyl clad and need painting. Do you know of a way to have them coated so they do not need to be repainted in the future? They are 11 years old and seem to be good wood windows. It is cost prohibitive to replace them with vinyl clad.
I don't know of a coating that won't require maintenance in the future. But, the time between repainting can be extended by using proper preparation techniques, a really good primer and paint.
Also, using a clear paintable caulking around the glass to the sash frame and the window frame to the house (siding or stucco) can extend the time before major peeling. This alone can get you another year.