No, you should not use cooking oil to oil wood, especially as a long-term finish or preservative.
While it might seem like a simple solution for adding moisture or shine to wood temporarily, culinary oils are not suitable for use as wood preservatives. Using them on wood can lead to undesirable outcomes over time.
Why Cooking Oil is Not Recommended for Wood
The primary reason cooking oils, such as vegetable oil or olive oil, are not recommended for wood is their composition and limited shelf life.
- They Go Rancid: Unlike specialized wood finishes or oils, cooking oils contain fats that oxidize and break down when exposed to air and light. This process is called rancidity. When cooking oil turns rancid on wood, it can emit unpleasant odors and potentially leave a sticky or gummy residue.
- Limited Shelf Life: As the reference states, even unopened vegetable oil has a limited shelf life (a couple of years), and once opened, it lasts for even less time. When applied to wood, this short lifespan means the oil will inevitably degrade.
- Not a Preservative: Cooking oils do not offer the protective qualities that wood finishes or oils specifically designed for wood provide. They don't properly seal the wood against moisture, resist mildew, or protect against wear and tear effectively. The reference explicitly warns, "Do not use culinary oils as wood preservatives."
Think of it this way: Cooking oil is meant for food consumption with a relatively short storage and use period. Wood finishes, on the other hand, are formulated to penetrate, cure, and protect wood surfaces for years, sometimes even decades.
What to Use Instead
For oiling wood, it is best to use products specifically designed for that purpose, such as:
- Tung oil: A penetrating finish that hardens and provides good water resistance.
- Linseed oil (boiled): Another penetrating oil that dries to a durable finish (ensure it is 'boiled' linseed oil, as raw linseed oil takes a very long time to dry).
- Mineral oil: Often used for cutting boards and kitchen utensils because it is food-safe and doesn't go rancid, although it doesn't cure or offer significant protection.
- Specific wood finishing oils: Various blends are available for different types of wood and desired finishes.
Using the correct product ensures your wood remains protected, looks good, and avoids the problems associated with using unsuitable materials like cooking oil.
