Peter: enjoy the form. I am ready to finish a fireplace mantle. It is old growth heart pine from a beam out of an old barn. Two sides are weathered and 2 sides are planed and sanded for a clear finish. This will be placed above a wood burning fireplace. What do you recommend for a finish? My main concern is what to apply to weathered sides, if anything; one is the bottom and the other is the 5″ edge facing out. The top and back edges are the planed/sanded sides. Thanks for your help.