During the American Civil War storage "cosmoline" was made from the triple mix of 1/3 raw linseed oil, 1/3 beeswax and 1/3 turpentine.
Many years ago Organic Gardening Magazine did a test on the above mixture against the more modern finishes such as Polyurethane, Varnish, Thompson's etc. During the several years the wood was in the weather the old mixture was the best. How bout that! The danger is that the mixture has to be heated so that the wax melts and mixture penetrates the wood.