It is common to hear: engine oil is good for woods? People have been applying used motor oil on wood as a stain and preservative for ages. Obviously, who wants to put money into paints and preservatives when he has a solution in his garage?

It may have many uses for wood but deciding if engine oil is good for wood or not is a long argument. Keeping in mind the benefits and consequences of using motor oil, let’s see if it leaves good outcomes on wood. 

Uses of Engine Oil on Wood

People around the world believe that engine oil is good for wood staining and preservative. Staining and furnishing things like wooden floors, trailer decks, furniture, and fences can cost you a lot. Motor oil is a cheaper and widely available alternative for these tasks.

Engine Oil as a Preservative Finish

The oil prevents wood from rotting by stabilizing it. It soaks into wood’s pores, allowing water to absorb slowly, hence preventing rot.

Engine oil is thrown out after every car treatment. Utilizing this waste as a preservative finish is a good option to some extent. It is usually used for outdoor projects and helps prevent mold, fungus, decay, and degradation. 

Moreover, engine oil stops insects and termites from attacking wooden projects for a year or so. 

Engine Oil as a Wood Stain

Why buy wood polishes when you can have one free of cost? Yes, engine oil works as a beautiful wood stain. Mix it with a trim diesel or add coloring to give a glossy brown finish to your wooden furniture.  

Oil and Diesel Mix Stain:

Oil and diesel, when mixed, make a beautiful wood stain. Below are the steps to make a wooden stain at home:

  1. Decide the color of the stain. You can either leave diesel and engine oil as they are, add oil dyes or roofing tar.
  2. Mix them thoroughly. 
  3. Put wood panel or furniture on to a mat to prevent engine oil from staining ground or contaminating soil.
  4. Start painting wood. Use a paintbrush, cloth, roller brush, or sponge to paint it. 
  5. Let it dry.
  6. Carefully clean the brush or dispose of the cloth. 

Not only this, oil and diesel mixture, when applied to wood, make it water and rot-resistant and keeps the wood nourished. 

Check out if engine oil is bad for paints. 

Wood Projects to Use Engine Oil On

We recommend you use motor oil for outdoor projects only. Not only does it evaporates toxic for human health, but it also takes too long to dry. Below are some projects to use motor oil on:

Is Engine Oil Good for Trailer Deck?

A great and cost-effective way to paint the trailer deck is by mixing motor oil and diesel. A thin layer of this mixture will dry under a few hours of sunlight and be an effective repellant against water and decay.

An intense durable trailer can lift heavy loads. Engine oil is good for the trailer deck.

Is Engine Oil Good for Fence Posts?

Staining wood can be expensive, especially when you have to color longer fences. A low-cost alternative is engine oil, which gives the fence a dark glossy look. 

Fences are open to harsh weather, winds, and rains. Motor oil coating prevents water from penetrating the wood and prevents rotting. If you treat fences with engine oil, their smell will keep animals away; thus, they won’t destroy the fences. 

Once dried, it is not flammable and won’t affect vegetation near it then. If you live in an area with low rainfall, engine oil can be good for your wooden fence posts. Else, we don’t recommend you to use it. 

Are you wondering if liquid motor oil is flammable? Read more about it here. 

Is Engine Oil Good for Painting Wooden Floors?

You may have seen people painting wooden floors with motor oil. It gives the floor dark and light brown shade and, obviously, reasonable protection from decay. Also, we paint floors to keep insects away.

We are doubtful about painting wooden floors with engine oil. Houses are closed thus are usually more humid than open air. In turn, engine oil stain will fill the house with unpleasant aroma and toxicity that won’t go away soon. 

Is Engine Oil Good for Painting Outdoor Furniture?

A wrong decision, though. Engine oil won’t cure. It will stay there on your furniture days after painting.

Even if it feels dry to touch, it isn’t really dry and will stick to your clothes whenever you sit on it. This is because engine oil does not solidify. It is better not to use engine oil to paint furniture. However, you can mix it with diesel to thin it and then apply a thin layer. 

Still, we will not recommend you to use engine oil as a finish on outdoor furniture.

Why is Engine Oil Not Good for Wood?

Untreated wood is like tissue paper that will soak up everything fed to it, whether it is engine oil, polishes, or wood preservatives. 

We have been using engine oil as a finish and stain since forever. Yes, it may be practical to some extent, but we can’t overlook its negatives. 

Engine Oil Toxicity

Unfortunately, the ones using used engine oil as finish don’t tell us that it contains heavy metals like lead, chromium, zinc, barium, and polyaromatic hydrocarbons. 

These toxins cause sewage problems and unproductive soil when exposed. Also, its poisonous nature can cause severe health problems. 

If you still want to use it, make sure to wear protective equipment, including gloves, respirator, and TVAC suit, to ensure maximum protection.

Read more about Engine Oil toxicity, guide, and precautions. 

Soil Contamination

Many of you may not know that disposal of used engine oil is illegal. Even if we dispose it on the ground, it causes soil impurity and leaves the land infertile forever.

Won’t Stop Smelling Like Motor Oil

Yes, bitter truth. Wherever you apply motor oil, unless it is the thinnest layer and kept it scorching sun for hours, that wood won’t stop smelling like motor oil. The nauseatic odor can be unbearable for many.  

It is a Water Pollutant

Do you know that 5 liters of oil can pollute 3.8 million liters of freshwater? Not only will this affect human health and marine life, but it also increases algae growth in water. 

Water Washes Off Engine Oil

Thin layers of oils are not resistant to water. If you apply a thin layer of oil for quick drying and lessen the smell, it will easily wash off in rainwater, leaving wood beneath exposed to decay and insects.

Engine Oil Won’t Dry

Most of the time, applying one layer of preservative won’t help. We reapply oil to form a thick layer that will be effective towards rot. 

The thick layer of oil won’t dry. Even if it feels dry to touch, it can still stick with clothes. Also, this wet coating readily attracts dirt and dust from the surroundings.

Engine Oil is Not an Effective Preservative Comparatively

No, I am not saying it won’t preserve wood or keeps insects away, but it is somewhat ineffective compared to other wood preservatives. Generally, wood preservatives dry soon, are water-resistant, and are not corrosive. 

Many people found motor oil to be comparatively less effective as it won’t preserve for more extended periods and easily wash off. 

FAQs – Is Engine Oil Good for Wood?

The questions below will help completely understand if engine oil is good for wood. 

Why Should You Reuse Motor Oil?

Reusing engine oil will save the planet. When we talk about waste motor oil, remember it is not actually waste, but dirty. Recycling and cleaning this oil will save resources.

If we waste used motor oil, it will either go in the ground or water, contaminating soil and water. Soil contamination results in infertile land, whereas water pollution affects human and marine life and destroys plants. 

Finally, recycling and reusing use lesser energy than making new motor oil.

How Long Does it Take for Engine Oil to Soak in Wood?

One day, few weeks, or even worse, never. It depends on the type of wood, the thickness of the layer if you are using a mixture of engine oil and diesel, and how long you keep it outside for drying.

A more absorbent wood will suck oil faster. The thinner the layer of engine oil, the faster it will dry. If your mixture engine oil with diesel, it will form a thinner blend, and wood will soak it faster. 

The more you keep the thing in sunlight, the faster it will dry. In humid weather, even the thin layer of engine oil can take many days to dry.

How to Remove Engine Oil Spill from Wood?

Depending on whether the stain is new or old, there are two different methods. 

If the stain is fresh, do the following:

  1. Cover the stain with paper as soon as the oil spills. 
  2. Mix detergent solution in a container.
  3. Spread the detergent solution on the stain only. (Applying it elsewhere can destroy wood)
  4. Scrub the stain with a brush.
  5. Pat dry with a clean, soft cloth.

If the stain is old, perform the following procedure:

  1. Apply mineral spirit on a clean cloth.
  2. Start rubbing the stain and repeat until the stain is gone.
  3. Dry that part of the wood with a clean cloth.

Make sure you perform the above procedure in a ventilated room. Wear gloves and a mask for safety. 

Does Motor Oil Kill Termites?

Yes, it does. Termite spread cellulose-digesting enzyme on wood. This enzyme breaks into food, and termites feed on them. Engine oil is toxic and gives the wood an unpleasant taste and smell, killing the termites attacking it. 

What Quantity of Engine Oil Should I Use as a Preservative on Wood?

50-50, mixed with diesel. If you choose to apply engine oil only, using a small quantity will be ineffective, or else rain will wash it off. 

Applying too much engine oil won’t ever dry. It will also cause pollution and become a danger to the soil, livestock, and marine life. 

A 50-50 combination with diesel will make engine oil thinner and quick-dry.

Conclusion – Is Engine Oil Good for Wood? 

After many years of using oil on wood, we still wonder if engine oil is good for wood. It is not. In the past, people didn’t care much about the environmental consequences of using engine oil and didn’t have many alternatives. 

However, today we know the harmful impacts of motor oil on this planet and living creatures. Also, we have eco-friendly and more efficient methods to stain and preserve the wood; hence, it is best not to use engine oil for wood.