Pine Tar is a traditional coating used on wood and metal. There are many recipes for 'boat soup' and homemade varnishes that include Pine Tar. Pine Tar was used for waterproofing inside and out for hundreds of years, dating at least as far back as the Vikings in the 9th century. Mix with japan drier, boiled linseed oil, and turpentine in appropriate quantities and proportions for a traditional varnish.