Why Can’t You Use Boiled Linseed Oil on Oak? Bad Idea?

You may have heard of linseed oil being used on wooden surfaces. Well, linseed oil is a popular product to apply on a wooden surface. It gives the surface a touch of class and finesse. The oil is water-resistant, eco-friendly and easy to apply.

In this article, we look into boiled linseed oil and its unique relationship with oak wood. We will answer why many experts advise against using boiled linseed oil on oak. We also explain why using this oil on your precious oak piece of furniture is a bad idea. We will take a deeper look at this linseed oil to best understand why using the boiled option on oak is a bad idea. We will look at its features and why it is a mismatch for oak.

Understanding boiled linseed oil

As you know, linseed is a popular seed, rich in protein and omega-3 fatty acids. But we are not into food today. This seed has a wide range of applications, and one of them is wood finishing. When pressed, the seed gives linseed oil.

When raw linseed oil is mixed with natural drying agents such as manganese or cobalt, boiled linseed oil is made. Contrary to what the name suggests, boiled linseed oil is not actually boiled. The additives added in boiled linseed oil shorten the drying time of the oil when exposed to an oxygen-rich environment. Rather than taking two or three weeks to dry, as is the case with raw linseed oil, the boiled version takes at most three days. This characteristic makes it an ideal ingredient in exterior linseed paint. The boiled linseed oil is popular for treating indoor woodwork.

Boiled linseed oil gives a mellow or patinanted look to a wooden surface. It is a superior type of finish as compared to raw linseed oil. Though a very popular wood finish, it is not recommended to be used on exterior oak. The good thing about this oil is that it can be used on stone floors, terracotta tiles or porous surfaces. You should then wax the surface to get that impeccable final finish. This oil is also preferred because it carries protective traits for wood.

You might come across double-boiled linseed oil. There is no added benefit to buying double-boiled linseed oil. It is just a marketing ploy used by sellers. In some quarters, linseed is also referred to as flaxseed oil.

On average, boiled linseed oil covers up to 20 square meters per liter. Three coats of boiled linseed oil are ideal on the surface you opt to apply it. While storing the finish, please keep it in a room where the temperature won’t go below 10oC or above 25oC. Also, keep it away from direct sunlight and ensure you use it within 3 years once it’s opened.

Why you shouldn’t use boiled linseed oil on oak

  • Oak is one of the most popular hardwood trees that give some of the best pieces of furniture. There are hundreds of oak species from all over the world. Oak lumber is popular because it is strong, heavy and dense. Moreover, since it contains high tannin, it presents you with very close grains. The type of wood is a darling to many homeowners because of its resistance to fungal and insect infestation.
  • Oak wood stands out because it is highly durable, besides obviously being eye candy. Even when exposed to intense light, oak furniture is unlikely to warp. The wood also is highly resistant to wear and tear and doesn’t easily get spoiled by water.
  • The one thing that oak is not very good at is its porousness. It is very porous when it is exposed to oil finishes. When exposed to boiled linseed oil or any other oil finish, oak wood will absorb it and take a very long time to dry. In other words, oak wood and boiled linseed oil are more like a sponge and water. It will absorb all, and it will take ages to dry.
  • Some oak trees have large pores. These pores will bleed when an oil finish is applied. If you see the pores bleeding, the boiled linseed oil finish, wipe away the deposits. You will need to wait for the wood to completely absorb the oil and dry. This process might take several days or weeks.
  • Oak has high tannin content. While tannin makes oak wood exude that original and beautiful color, it doesn’t work well with some finishes and paints. Tannin is one of the many substances found in oak. It is a phenolic substance that contributes to the way oak lumber looks.
  • During cold, wet weather, oak furniture will react badly if an oil finish has been applied. This is why boiled linseed oil is not applied on oak wood, especially those likely to get exposed to water and cold weather. Rather than enhancing the durability trait of oak, boiled linseed oil shortens its lifespan. It also makes the wood lose its appeal when exposed to the outdoor environment over time.
  • Treating oak with boiled linseed oil is never a good idea. The problem is that besides the oak project bleeding from the pores and requiring a lot of patience to complete the project, cold, wet weather might be a threat. Using boiled linseed oil is especially not advisable when working on exterior projects.

What projects should you use boiled linseed oil on?

Boiled linseed oil provides a long-lasting glossy sheen to a wooden surface. Besides being suitable for use on all wooden surfaces, the oil gives porous rocks a unique look. But as stated earlier, boiled linseed oil is not recommended for use on exterior oak. The oil protects the interior and the exterior part of the wood. The raw linseed oil complies with Food Regulations and can be used on wooden utensils in the kitchen and dining areas. However, it is worth noting that boiled linseed oil is not food safe and should not be applied on worktops or dining surfaces where it might peel onto food.

Here are some of the projects you can use boiled linseed oil for

Boiled linseed oil can be used on oak surfaces, provided they are on the interior and away from the danger of getting into contact with water and extremely cold weather.

  • It can be used on both interior and exterior surfaces of wooden surfaces
  • Hardwood floors
  • Doors and windows
  • It can be used on untreated wood and bare wood
  • Stained and unfinished wood
  • Can be used on porous stone surfaces before waxing
  • The oil is used to preserve metal by preventing the oxidation of the surface

It is worth noting that boiled linseed oil is not suitable for use on varnished or lacquered wood. Such treated surfaces prevent the oil from being soaked by the wood, making it ineffective on such treated surfaces. To maintain a natural luster, apply a coat once yearly or when the surface shows signs of ‘drying.’

Simple tips on how to give oak the best finish

It is pretty easy to give your oak piece of furniture a dazzling look by following a few simple steps. No matter the type of finish you intend to apply on your oak piece of furniture, these steps will play a critical role in helping you get the desired results;

  1. Sand the surfaces starting with greater girt and finishing with 120 grit. You should then vacuum and wipe away all dust before applying the finish. While sanding, make sure you move along the grains and not across.
  2. For the oil-based finish, wait overnight before applying the topcoat after you apply an oil-based stain. If the stain is water-based, you only need to wait four hours.
  3. Wait overnight before applying a consecutive coat to get the best results when applying an oil-based finish.
  4. It is advisable to scuff-sand the surface between each topcoat with 320-grit sandpaper.

How do you apply boiled linseed oil to a wood project?

First, you should note that boiled linseed oil is highly flammable. You should therefore take care when using it in your home. The project you are working on should be in a well-ventilated place.

Pour the boiled linseed oil onto the section of wood you want to work on. You should work in small sections to help you apply the oil as evenly as possible. Pour adequate oil. It is better to use more than not enough boiled linseed oil at first.

Use a soft, non-abrasive cloth like cotton to apply boiled linseed oil. Even though this oil is not toxic, it can still be irritable, and it is advisable to use a safety face mask.


Boiled linseed oil though yellowish in color, gives oak a very original and suave appeal. However, as highlighted above, oak wood has numerous pores, making applying this oil not a great idea. This is especially the case on the exterior, where the wood is likely to get into contact with water and exposed to cold weather.