The formby's "tung oil" is not tung oil. Get some 100% tung oil and it will be VERY waterproof after about 5 coats. I would sand the formby's all the way off. It is soft, shiny, and does not repel water. I think it is desgined for hand rails and bannisters. Wood crafter carries and excellent 100% tung oil. I have a 12 ounce bottle, have done more than a dozen bows, and still have most of it left. Just remeber to push ALL of the air out of the bottle between openings