I have a home that was built in 1987. The windows are wood and I can not get the paint to stick to the windows for more than 12 months. The latest round of painting I tried using a Minwax product "wood hardener" followed by two coats of a good water based primer and two coats of the final color. The paint hold to all but the lower sach and it peels over time. What can I do short of replacing the windows to get the paint to stick. Any and all suggestions with specific products would be greatly appreciated.