We have a very old log home that is made of axe hewed logs. The log home was orginally an old train depot station that was dismantled and rebuilt many years ago by great uncle and grandfather on the Greenbrier River in Wv. Several years ago (15 years +/- a few years)the logs were painted grey to imitate original look. Of course this did not give the expected results. Researching recently that painting was a bad idea. My question is cob blasting the best solution to returning the logs to or