You can rent a "corn-media blaster" (they use corn cobs instead of sand to keep from damaging the logs) to remove your old finish and then apply new sealer, stain and top coat. Our log home was just sealed, stained, and clear coated last week. The current recommended product is made by Perma-Chink Systems, Inc. Their website is http://www.permachink.com
. My son is planning to use this to re-finish his log home that was completed in 2002.