There are many wooden utensils, such as carved spoons, turned bowls, and butcher blocks, that need finishing. If these items are meant for more than just looks and actually serve a purpose, it brings up some important questions. For instance, what kind of finish should be used, and is it safe for food contact? Tung oil is an excellent choice for finishing these pieces, but is it safe for food? Let’s explore and find out.
What is Tung oil finish?
Tung oil, a relatively recent addition to finishes in this country, has gained popularity over the years. Originally derived from the nuts of tung trees native to China, tung oil was introduced to the United States in the early 20th century. Tung oil stands out from linseed oil in several ways. Firstly, it has a minimal darkening effect on wood and dries at a significantly faster rate. Moreover, when fully cured, tung oil exhibits excellent water and moisture-repellency. In terms of durability, tung oil surpasses linseed oil by offering enhanced longevity and resilience.
Is Tung oil food safe?
Yes, a surface finished with tung oil can indeed be considered food safe, as long as the tung oil finish has undergone complete curing through oxidation. This designation is supported by the FDA, as stated (FDA Code of Federal Regulations for food contact substances, 2023) coatings must be fully cured to ensure food safety.
How tung oil cures
Tung oil cures through a process called polymerization. When tung oil is applied to a surface, it starts to react with the oxygen in the air. This reaction causes the tung oil molecules to crosslink and form a solid film. The curing process typically involves the following stages:
- Penetration: Initially, tung oil penetrates into the wood or substrate, soaking into the pores and creating a bond with the surface.
- Oxidation: As the tung oil is exposed to air, it begins to oxidize. Oxygen reacts with the oil, causing it to undergo a chemical transformation.
- Polymerization: During oxidation, the tung oil molecules start to polymerize, forming long chains or networks of molecules. This polymerization process leads to the development of a solid and durable film on the surface.
- Curing Time: Tung oil requires time to fully cure and harden. The exact curing time can vary depending on factors such as temperature, humidity, and the specific brand or formulation of tung oil. It can take several days to several weeks for the tung oil finish to reach its maximum hardness and durability.
It’s important to note that proper curing is essential to achieve the desired properties of a tung oil finish, including enhanced durability and food safety. It is recommended to follow the manufacturer’s instructions regarding curing time and conditions for the specific tung oil product being used.
Tung Oil Finishes: Brands, Formulations, and Food Safety
Tung oil finish varies widely among brands. As an oil tung oil dries quite slowly and to navigate this issue and metal driers and resins are added to tung oil. The blends and formulas will vary from one brand to the next. However, there are still some manufacturers that sell 100% pure tung oil. In this section we will look at some common tung oil products and whether they are food safe.
Is Watco tung oil food safe
Yes, Watco tung oil can be considered food safe, provided that it has been given sufficient time to fully cure. Watco, along with other similar brands, incorporates metal driers in their tung oil formulations to expedite the drying and curing process. It’s worth noting that the metal driers used in these products are all listed as food safe by the FDA. Therefore, when the tung oil finish has undergone complete curing, it can be considered safe for food contact.
Is minwax tung oil food safe
When it comes to Minwax tung oil, it can indeed be considered food safe, provided that the tung oil has undergone the necessary oxidation process and has fully cured. Like other tung oil finishes, Minwax tung oil undergoes a curing process through oxidation, where the tung oil molecules react with oxygen in the air. This reaction leads to the formation of a solid film that is safe for food contact.
Summary: Is tung oil food safe
- Tung oil is an excellent choice for finishing wooden utensils, offering minimal darkening, faster drying, water resistance, and enhanced durability.
- Tung oil finishes are considered food safe once fully cured through oxidation.
- Tung oil cures through a process of polymerization, forming a solid film on the surface.
- Curing time for tung oil can vary, but it typically takes days to weeks to reach maximum hardness and durability.
- Brands like Watco and Minwax offer tung oil finishes that are considered food safe after complete curing.
- Metal driers used in tung oil formulations are listed as food safe by the FDA.
- It’s important to follow manufacturer instructions for curing time and conditions to achieve desired properties and ensure food safety.