We have a cedar porch and tongue and groove ceiling. A few years ago I put clear Spar polyurethane on the cedar, but the finish seems to be breaking down . The majority of the wood was nailed with stainless steel nails, but my husband saw a few gaps and used plain steel finishing nails and I'm thinking this is where the major discoloration is happening on the boards that are exposed to weather. I have more than one question so bare with me. The first being how to get rid of the dark spots? I've been told a few ways by people at Lowes (1) counter sink nails, apply Zinsser to the nail heads,cover with wood sealer, clean with TSP. (2) counter sink nails, fill with paintable caulk, clean with Olympic deck cleaner, lightly sand paper 60-80 grit. (3) remove nails though that's pretty hard to do since they are flush & finishing nails.
The second question is when the stain is gone what product & stain color should we use on this
porch? I was told by an Olympic rep that the darker the stain the less discoloration happens.
We love the color it is now but are willing to darken it a little. I've even toyed with the idea of giving the ceiling (free from the rain)a clear coat and giving the rest a slightly darker stain but not sure how that would look.
Would like advice to fix and prevent future problems. Also, If you notice in one pic there is a portion stained darker than the rest that was done a few years ago and not sure if that color would look good on the posts while leaving the ceiling natural.
Thank you for your help in this.