Cold-Pressed Tung Oil: Why the Extraction Method Matters
When you buy pure tung oil, the ingredient list tells you what is in the container. It does not always tell you how the oil got there. Different extraction methods can involve different temperatures, equipment, solvents, and processing steps.
At RMP Finishes, we think both matter. Our Pure Tung Oil contains one ingredient: 100% pure tung oil. It is mechanically cold-pressed from tung tree seeds at 60–70°F, with no hexane, chemical solvents, or extraction additives used to remove the oil from the seed.
Understanding that process can help you make a more informed choice when comparing tung oils and other wood finishes.
How Is Tung Oil Extracted?
Tung oil comes from the seeds of the tung tree (Vernicia fordii). After harvesting and preparing the seeds, the oil must be separated from the solid seed material.
One way to do this is through mechanical pressing. Pressure physically squeezes the oil from the seeds. This is the basic method used to produce RMP Finishes Pure Tung Oil.
Another approach used in commercial vegetable oil production is solvent extraction. A chemical solvent is introduced to help dissolve and recover oil from plant material. The solvent must then be separated from the extracted oil through additional processing.
Hexane has historically been used for this purpose in commercial oilseed processing because it can help recover more oil than mechanical pressing alone.
RMP Finishes does not use this extraction method. Instead, our Pure Tung Oil is mechanically cold-pressed.
What Does Cold-Pressed Tung Oil Mean?
Cold pressing means the oil is extracted mechanically while the temperature is controlled throughout the process.
Simply calling an oil “mechanically pressed” does not necessarily mean it was cold-pressed. Mechanical equipment can generate heat through friction, and some production methods intentionally heat or condition seeds before pressing.
That is why we are specific about our process.
RMP Finishes Pure Tung Oil is mechanically cold-pressed at 60–70°F. We do not use chemical solvents or extraction additives to pull additional oil from the tung seed.
The finished product remains just as simple: 100% pure tung oil.
Pure Tung Oil (Chinawood Oil)
Why Does the Extraction Method Matter?
The terms “pure,” “cold-pressed,” and “solvent-free extraction” describe different parts of a product.
- 100% pure tung oil tells you what is in the finished product.
- Cold-pressed tung oildescribes how the oil was mechanically extracted under controlled temperatures.
- No chemical solvent extraction describes what was not used to separate the oil from the seed.
This distinction matters because a product can potentially contain only tung oil when it reaches the container even if other substances were involved earlier in manufacturing and later removed.
For us, the issue comes down to simplicity and transparency. We want customers to know both what they are applying to their projects and how the oil was produced.
It is also important to distinguish Pure Tung Oil from products marketed as a “tung oil finish.” Depending on the formulation, those products may contain varnishes, mineral spirits, polymers, drying agents, or other ingredients.
RMP Finishes Pure Tung Oil contains only tung oil.
Can You Tell How Tung Oil Was Extracted?
You generally cannot determine an oil’s extraction method by looking at its color, clarity, viscosity, odor, or drying behavior.
Laboratories can test products for residual solvents. Published research has used gas chromatography with flame ionization detection (GC/FID) and gas chromatography with mass spectrometry (GC/MS) to detect and measure residual hexane in oils and other products.
GC/FID separates volatile compounds and measures them using a flame ionization detector. GC/MS also separates compounds but combines chromatography with mass spectrometry to help identify compounds based on their molecular characteristics.
There is still an important limitation.
A laboratory finding of no detectable residual solvent means the test did not detect that substance above the method’s detection threshold in the tested sample. It does not necessarily prove that the solvent was never used earlier in manufacturing and later removed.
If you specifically want to know how an oil was extracted, manufacturing information and supplier transparency matter alongside laboratory testing. Clear disclosure of the production method can tell you something a finished-product test alone may not: how the oil was actually extracted.
How RMP Finishes Pure Tung Oil Is Made
For us, producing Pure Tung Oil starts with keeping the product and the process as straightforward as possible. Our process gives you:
- 100% pure tung oil
- Mechanically cold-pressed at 60–70°F
- Extracted without hexane or chemical solvents
- Made without chemical extraction additives
- Free from added varnishes, mineral spirits, or polymers
We use this process because it aligns with what we want Pure Tung Oil to be: a straightforward, traditional wood finish with a production method we can clearly explain.
Once applied to bare, porous wood, Pure Tung Oil penetrates the surface and cures through oxidation. When fully cured, it produces a water-resistant matte finish that enhances the material’s natural grain and character.
It can be used on furniture, countertops, cutting boards, floors, woodworking projects, and other porous surfaces.
FAQs About Cold-Pressed Tung Oil
Is RMP Finishes Pure Tung Oil 100% pure?
Yes. RMP Finishes Pure Tung Oil contains one ingredient: 100% pure tung oil. It contains no added varnishes, mineral spirits, polymers, or other finishing ingredients.
How is RMP Finishes Pure Tung Oil extracted?
We mechanically cold-press our Pure Tung Oil from tung tree seeds at 60–70°F. We use physical pressure to extract the oil rather than chemical solvent extraction.
Does RMP Finishes use hexane to extract Pure Tung Oil?
No. We do not use hexane to extract RMP Finishes Pure Tung Oil. We also do not use other chemical solvents or chemical extraction additives to remove the oil from the seeds.
Is cold-pressed tung oil the same as a tung oil finish?
Not necessarily. Pure tung oil is the oil itself, while products marketed as “tung oil finish” may contain additional ingredients such as varnishes, solvents, polymers, or drying agents. Check the product’s ingredient information before choosing a finish.
What surfaces can Pure Tung Oil be used on?
Pure Tung Oil works best on bare, porous surfaces where the oil can penetrate. Common applications include furniture, countertops, cutting boards, floors, woodworking projects, and other absorbent surfaces.
Know What Is Behind the Label
Choosing a wood finish shouldn’t involve guesswork. While a clean ingredient list matters, true transparency means knowing exactly how your oil was extracted before it reaches the container. By keeping our cold-pressing process strictly mechanical, we keep the finish true to its historic purpose: a straightforward, non-toxic way to protect wood while naturally enhancing its grain. Whether you are tackling a vegan-friendly furniture restoration, sealing a kitchen countertop, or finalizing a custom build, you deserve materials you can trust.
For your next furniture restoration, woodworking, countertop, cutting board, or other porous-surface project, explore our Pure Tung Oil and our other traditional finishing oils.
