If you check with a marina supplies store, you can buy Tung Oil.

Most of the “Tung Oil” in commerce isn’t the pure oil but may (or may not) only contain a small percentage of the true oil with the rest being solvents, varnish, etc., etc. (see; http://en.wikipedia.org/wiki/Tung_oil ). For more on the tung tree, see; http://en.wikipedia.org/wiki/Tung_tree ).
;-)

C.J.V. - got a 3-foot one in the yard and 3 or 2 more 1-foot ones in pots to plant out this year, me