Non Toxic Finishes

Or to finish or not to finish      ”

As we build smaller and smaller homes, tiny houses and micro homes, the materials that are used in that home becomes increasingly more important. In a 2600 sqft home, there is considerably more space for some toxins to dissipate into the environment. The parts per million of these toxins becomes small on that scale, and don’t get me wrong – they are still there wrecking havoc on ones immune systems. The long term effects, just like inhaling second hand smoke can be more deadly that smoking it seems.

In a tiny house, the overall space is considerably smaller, and therefore small amounts of toxins will impact ones environmental sensitiveness faster. And the very last step is where one can introduce toxins to the home; in wall coverings, paints, floor finishes, stains, and sealers.

We have noticed that one of the favorites in finishing woods by painters is polyurethanes. However, that is not the best coating to apply, it may be easier, and yet it is not a safe coating.

Polyurethane – Has been notoriously toxic. Most always related to a plastic in some form or another. Even the waterborne polyurethane can be very dangerous. The process of burning polyurethane has been known to cause dioxin to be created. Dioxin is one of the most poisonous substances on earth. Some good chemistry based descriptions can be found here about polyurethane production. There are tons of great uses for polyurethane but it doesn’t biodegrade well and it’s poison to burn.

The best thing about polyurethane, is how hard it gets. It gets harder than most other coatings. It is appropriate for industrial use occasionally. There are some high solids polyurethanes for industrial use but these are expensive and must be applied with special care. We don’t suggest poly for residential use or for small businesses. Coating wood in this plastic seems like a waste since it looks poor and fails quickly outdoors. There is simply too high a price paid envirosocially, for the few benefits of polyurethane. Natural wood finishes are much better choices.

We have used poly in the past, and do not use or recommend it for the home or office. We also stay away from other petro-based products for interior coatings.

2 of the products/methods we suggest using are Tung Oil or a Walnut Oil Beeswax Finish. We will discuss Tung oil in part 1.

Finishing with Tung Oil

TUNG OIL HISTORY: Pure Tung Oil was and is one of the first truely “Green” finishes. It is all natural and contains zero VOC’s. Pure Tung oil (China wood oil) is a all natural finishing product that provides a tough, flexible and highly water-resistant coating. It is classed as a drying oil along with linseed, poppy seed, safflower seed, walnut, soybean, oiticica and a few other oils. Although it is relatively new to the Western world, tung oil also known as chinawood oil has been known for centuries to the Chinese, and until this century, China was the main source for the oil. It comes from the seed of the tung trees, Aleurites fordii and Aleurites montana, deciduous trees that are very susceptible to frost damage. This vulnerability has restricted the cultivation of the tung trees to China and South America. Tung oil (china wood oil) received wide application in China: in the building trades as a treatment for both stone and wooden structures; in marine trades as a preservative and water repellant on wooden boats. It is said to have been introduced to the West by Marco Polo. From the 13th to the 19th century, tung oil had only limited use in the West. More recently, Tung oil has gained favor over linseed oil for wood finishing because it is faster drying and does not darken as much with age.

For ease of application, a solvent such as mineral spirits or citrus solvent is used. The mineral spirits is considered a toxic application while being applied, and the solvent quickly dissipates during the drying process. The citrus solvent is a natural solvent that is non toxic and does the same thing as mineral spirits. Mineral spirits and citrus solvent are used as “thinning agents” for easier applications of the Tung oil.


  • Zero VOC’s
  • All Natural means “Green”
  • Naturally polymerizing finish
  • Cures by oxidation not evaporation
  • Does not form a glossy finish no matter the number of coats
  • Form a flexible water proof finish
  • Resists abrasion and acids
  • Does not blister and peel (properly applied)
  • Does not mold like linseed oil
  • Long shelf life (will last for years, properly sealed)
  • Does not darken with time like linseed oil
  • Concentrated (thin one to one, doubles the coverage)
  • Combined with “Citrus Solvent” makes an all natural finish
  • FDA approved for food contact

Finding Tung Oil;

Tung Oil can be found on line here, or a good woodworking store such as Rockler Woodworking.


Step 1; Lightly sand the area with a 120 grit sandpaper, or oscillating orbital sander. Using a shop vac and dust cloth such as tac cloth; dust/clean the surface to remove dust and debris.

Step 2; Thin the Tung Oil 1:1, stirring the product until mixed thoroughly.

Step 3; Using a rag; dip the rag in the Tung oil and apply it to the area liberally. Making sure not to over Hand rubbed Tung Oil in a Tiny Houseapply to heavily, then rub the product into the surface being applied, and allow 10 minutes to soak into the wood.

Step 4; After about 10 to 15 minutes use old rags to rub the surface to remove excess Tung oil and weeping  of joints. Nathann is shown rubbing the excess Tung oil from the White Ash Paneling.

Step 5; Repeat step 2 and 3 although do not apply as liberally as in step 2. For high traffic areas such as floors, 2 to 4 costs are recommended for protection.

Part 2, Walnut Oil and Beeswax

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