Pure Tung Oil is just what it says, Pure Tung Oil, without any additive or petroleum distillates like mineral spirits or paint thinners. Formulated “Tung Oil” or “Tung Oil Finish” products can be any of a number of things from a thinned down varnish to a polymerized Tung oil. So you really don’t know what you are getting. Most Tung Oil finishes have petroleum distillates added and generally metallic dryers. Tung Oil will generally build a gloss finish as well as build on top of the wood surface. These types of finish dry overnight and require sanding between coats.
Pure Tung Oil will not build a gloss finish or build a heavy finish on the wood but penetrates deeply into the wood to enhance the character and water resistance. Kind of like seasoning your wood like a cast iron pan. It fills the open cell in the wood then naturally polymerizes inside the wood. Pure Tung Oil is easy to maintain with a follow-up application. It however does dry slower than Tung Oil. No sanding is required between coats. Just be sure the surface is clean and free of dirt. Pure Tung Oil will take 10 to 15 for a partial cure and 15 to 30 days for a full cure. Pure Tung Oil is the toughest longest lasting all-natural finish on earth.
If you want to make your own Formulated Tung Oil Finish, here is an old cabinetmaker formula:
- 1/3 Pure Tung Oil
- 1/3 varnish, polyurethane or oil base finish
- 1/3 mineral spirits or citrus solvents
You can vary the ingredients to adjust the working qualities of the finish.