Looking at examples of homes built with 'reclaimed' materials, I notice that much of the old wood utilized in new construction appears to be unfinished. (for examples, see July issue, pages 24 through 31, the 850SF 'entertainment cabin') Does wood reach a point where it has 'settled' or aged such that it does not need to be finished, even when used in an exterior application? My only guess is that old wood achieves some sort of weathered 'finish' that allows it to protect itself. sort of the same way that unfinished steel develops a coating of rust that can serve as a protective 'finish.' Or am I misssing something, and all of the wood on that old barn is actually finished with some type of product? Please expain - does old, weathered wood somehow not require a finish coating? (please cover both interior and exterior applications, because the article in the July issue makes it appear that old wood can be used anywhere without any need for even a basic oil coat.