Boiled linseed oil by itself isn't a good moisture barrier. Jay Massey used to use French Polish, a mixture of linseed oil and shellac which seemed to serve him well when he hunted wet Alaska but then developed Massey finish, epoxy thinned with spirits of some sort. Tru-Oil is a linseed oil product with other additives. It has worked well for me for many years on bows, arrows and gun stocks it's original intended purpose.
