... producing countries are mainland China and South America (Argentina and Paraguay), United States and Africa . Tung tree farms in the ... For centuries tung oil has been used for paints and waterproof coatings, and as a component of caulk and mortar. ... ability to dry quickly and polymerize into a tough, glossy, waterproof coating has made it especially valuable in paints, varnishes, linoleum, oilcloth ...