My sofits are finished with pine boards. I finished them with three coats of spar urethane. They are starting to have black spots under the finish. There is no mold anywhere on the house. Any idea of what would cause this and how to get rid of these spots? Thanks, D R
waterloop Changed status to publish April 9, 2024
No way to get rid of them without stripping. The urethane may have linseed oil in it which would promote the black mold under the finish. The boards may have had some moisture in them still also. Even kiln dried boards, if used too soon after coming out of the kiln will go back up in moisture content. They need to be dried naturally for awhile first.