I recently purchased a relatively poorly constructed and poorly maintained log home at a "bargain" price. It is only 12 years old but has some water issues. I have found the top of a couple of logs that are exposed to the weather at the corners, that have some rot. The extent and location is not a structural issue but not I am concerned about the future condition. Now there is a section that is a few inches is all 3 dimensions. What can I do to fill these areas in and protect it from further damage?