Question from Cecilia
Dear Debra, Are tung oil and linseed oil safe as wood furniture finishes? Pacific Rim uses a blend of tung oil, linseed oil, and Varathane in their furniture.
Thank you!
Debra’s Answer
Tung Oil comes from cold pressing of the seeds or nuts of the Tung tree. Tung trees mainly grow in the mountainous regions of China. The oil has been prized for centuries for it’s qualities as a wood finish. Tung oil penetrates deeply into wood, enhancing the character of the wood while creating a beautiful water-resistant finish. The ancient Chinese used tung oil to waterproof ships.
These qualities make tung oil perfect for wood bowls, counter tops, outdoor furniture, decks, wood siding, wood flooring, concrete, brick and just about any porous surface that needs a nontoxic waterproof protection.
When choosing a tung oil, it’s important to select one that has no additives or distillates. Tung oil labeled “pure” should be just that. Check the MSDS to see if there are any additional ingredient. One tung oil product I checked had 73.77% Stoddard Solvent (aka petroleum distillates), plus Trimethylbenzene, Ethylbenzene, and Cobalt Naphthenate, all very toxic VOCs.
Because the source of tung oil is a nut, people with nut allergies should avoid contact with (or even the odour of) tung oil. Otherwise, pure tung oil is a safe and natural finish.
Linseed oil is obtained from the dried ripe seeds of the flax plant, which is also used to make linen fabric. The oil is obtained by cold pressing, sometimes followed by solvent extraction.
Linseed oil has “polymer-forming properties, which means the molecules have characteristics similar to plastics. Linseed oil is used on its own or blended with other oils, resins, and solvents to make wood finish, to bind pigments in oil paints, as a plasticizer and hardener in putty and in the manufacture of linoleum.
Allow me to set the record straight. The tung “nut” is not a nut, it is a seed.
I would be cautious of any product containing petroleum products. Just because there are no reports of anything “bad” happening isn’t good enough in my book. Many of these toxins build up over the years and do no manifest themselves until much later in life. I know this as a fact dealing with it with doctors who are trying to help one of my family members who was exposed to pesticides. Furthermore, what about the employees who have to apply the product or handle it until it is safe? I am sure they have “some” protection but every shop I have visited is not foolproof in its handling of hazardous substances and OSHA standards.
I feel it is best to take the most natural route and only use polymerized linseed oil. It is simply “raw” linseed oil that has been heated. Nothing has been added. It may not cure as quickly as your typical tung or “boiled” linseed oil but it is so much safer. The linseed oil we use is actually the non-food grade version of flax seed oil that many people ingest daily as a supplement for Omega 3 Fatty Acids.
As for scratches, linseed oil is so much easier to repair- simply sand and reapply linseed oil. You can’t do that with polyurathane top coats.
Hi Debra,
As a follow-up to this, what about the use of this finish on baby cribs? Would the varathane in the finish be harmful if a baby chewed on the rails or slats of the crib?
Thank you!
COMMENT FROM DEBRA:
As far as I know, the finish is completely inert when fully cured. So based on that the answer would be no, the finish would not be harmful.
does tung oil contains additives which prevents it from polyerisation within the container in which it is contained.