One second-floor wooden window sill butts against the first-floor roof. Because of this, snow and water often sit on the window sill. Not only does the paint peel here, but the wood shows many small cracks from expansion/contraction. The cracks are 1" to 4" long, and as wide as 1/32". My previous "paint" was Sherwin Williams Woodscapes solid stain. Most of the house is still in good shape, but this window sill needs attention. Although the window sill is 30 years old, the wood is surprisingly still sound, other than the cracks. It isn't soft or decaying.
I called Sherwin Williams, Benjamin Moore, and Valspar and asked for advice. SW and BM said that there's nothing that will work well in this situation - good bye. Valspar said use a good combination paint/primer and you'll be fine. Neither left me feeling good with their responses.
1) How can I effectively fill the cracks? Putty? Caulk? Epoxy?
2) What would be an effective treatment (sealer? primer? paint?) for this situation?
Is there a sheet vinyl product that can be glued or nailed over wood to protect it instead of paint? What about a marine paint or a two-part paint?
What would you do?
Thank you for your help.