Tung oil hardens upon exposure to air (through polymerization), and the resulting coating is transparent and has a deep, almost wet look.

[9] The primary constituent is a fatty acid with a chain of 18 linked carbon atoms or methylene units containing three conjugated double bonds.

Tung oil is a common traditional wood finish, used typically for two main properties: first, it is a naturally derived substance.

When applied in many fine/thinner coats over wood, tung oil slowly cures to a matte/light satin look with slight golden tint.

[12] Heating tung oil to about 500 °F (260 °C)[13] in an oxygen-free environment will substantially increase the viscosity and film-forming quality of the product.

Primary coats may be laid down at a 1:1 oil-to-thinner ratio, and successive layers, if not absorbed into the wood, at higher solvent to oil concentrations.

Straight oil is then applied moderately to adhere to the surface and provide a good base for the thick gloss layers.

The polymerized oil is then applied thickly as a single layer, allowed to fully dry, buffed smooth with very fine sandpaper and 0000 steel wool.