Linseed oil (also called flaxseed oil) is a popular finishing oil that can be used for any woodworking project.
This eco-friendly and non-toxic fluid extracted from flax seeds provides an ideal protective coat to your furniture while also enhancing its natural beauty with added character qualities like glossing effects depending on what you want out of it.
Not only that but linseed oil is also widely used as:
- A solvent to clean paint brushes
- An anti-rust agent for various types of metals
- An oil paint additive to enhance its color and workability
- A nutritional supplement due to its several health benefits
- A cleaner and conditioner for leather products like jackets, shoes, etc.
If you are interested in learning more about this amazing wood finishing product, and why it’s getting so much popular among DIYers, jump over here to know its pros and cons first quickly…
|Yellows over time
|Need regular maintenance
|No UV resistance
|Support mildew growth
|Susceptible to water rings
|Can be used as a wood conditioner
|Carries a distinctly unpleasant smell
|Hides the dents and scratches
|Enhances the wood’s appearance
But that’s a very quick summary of what linseed oil is and how it benefits. So, let’s take a more in-depth look into what this finishing product can do for your woodworking projects and what are its real drawbacks you should know about before getting started.
Advantages of Linseed Oil for Wood
The benefits of linseed oil are many, and that’s the reason why it’s a popular product used for centuries.
Here are a few key assets that I have found with this product.
1- It’s an Eco-Friendly Product
Linseed oil is derived from flax seeds, making it a sustainable, biodegradable finishing oil that does not contain harmful ingredients or chemicals to damage the environment.
Most of the finishing oils, including lead acetate and cobalt-manganese compounds, are harmful to the environment. Drying agents such as these may aid in the drying process. However, they may also harm the environment due to their ability to damage materials.
Raw, as well as boiled Linseed oil, is free from such drying agents. This can take longer for Linseed oil finishes to dry than other types of oils (due to its natural properties), but still, many people prefer using this over others with harsh chemicals as their final step in creating beautiful furniture pieces from scratch.
2- Linseed Oil is Non-Toxic
As mentioned before, linseed oil is extracted by crushing flax seeds which are edible. Because of this, the oil it produces is also non-toxic in nature. In other terms, it doesn’t contain any VOCs or artificial chemicals that can be hazardous.
Linseed oil usually gets hardened upon exposure to the air. It undergoes an oxidation reaction while losing heat, which is not harmful to humans or most animals.
This all means:
- It’s a good choice for any woodworking project, as it will not cause harm to humans or animals.
- If you are planning to use it for finishing wooden kitchen utensils or wood-made children’s toys, it’s completely safe.
- If used to finish your lovely garden beds, birdhouses, or animal cages – it is plant and animal-safe.
- It’s also helpful as an effective insecticide for repelling many common pests and fungi.
Linseed oil takes a long time to harden, so be sure to apply it and allow it to dry and cure for at least a week before using it.
3- Linseed Oil is Food Safe
One of the greatest benefits is you can use linseed oil on any wooden surface that comes into contact with food, including utensils, bowls, spoons, cutting boards, butcher blocks, and kitchen countertops.
Do remember that – Raw linseed oil is safe for consumption, but boiled linseed oil is not. So, make sure to only use raw linseed oil in your kitchen.
To be on the safer side, I recommend checking the manual or instructions label that comes on the oil bottle. Since there are a few synthetic Linseed oils that use chemicals, it must be printed on their label whether it’s safe for direct contact with food or not.
When chosen and applied wisely, it provides a beautiful, sophisticated look to your kitchen wood surfaces while also providing additional protection from environmental elements like moisture.
4- Linseed Oil is Water-resistant
Being hydrophobic (ability to repel water), Linseed oil is a natural waterproofing agent and offers some resistance to moisture and water particles. But it’s not waterproof so, it cannot protect wood under high moisture conditions.
This also means linseed oil can prevent water damage indoors on surfaces such as bathrooms and kitchens. However, you must be vigilant in keeping an eye on any outdoor surface you treat with Linseed oil, as it will not protect the wood from heavy rains.
If you plan to use linseed oil-finished furniture outdoors, be sure to use them in the shade or cover them with a tarp during rainstorms. The internal structure of the wood may begin to decay as a result of water particles breaking through the barrier and entering the wooden surface if not protected correctly.
5- Provides Good Elasticity and Stretchability
Elasticity and stretchability of the wood finish refer to its ability to expand and contract with the wood as it swells and shrinks due to changes in humidity.
Many wood finishes are not elastic and can crack and peel as the wood expands and contracts due to changes in temperature and humidity, along with other physical or chemical effects.
Linseed oil, on the other hand, is a good option for an elastic and stretchable wood finish because of its polymerized flexible behavior.
This means if you apply the layer of linseed oil as a finisher correctly, it will adjust its shape accordingly to the changes in your wood surfaces. And because it is flexible and works well with wooden surfaces, linseed oil prevents cracking, peeling, and wearing down from shear forces.
And did I mention that linseed oil’s elasticity does not change even after it is fully cured and turned into a polymerized state? So, you need not worry about it losing its elasticity over time.
6- Linseed Oil is Easy to Apply on Wood
Applying linseed oil is not difficult and does not require any fancy equipment. If you have ever applied furniture polish or oil to wood, then you can easily apply linseed oil in the same manner.
All you need is a lint-free cloth and the appropriate amount of linseed oil.
- Start by wiping the wood surface with a lint-free cloth to remove all the dust, dirt, and grime.
- Next, sand the wood surface with 120 grit sandpaper, and clean the sanded dust with a piece of rag.
- Now, pour a small amount of linseed oil onto the cloth and rub the cloth with oil on the surface of the wood along the direction of the wood grain.
- Keep rubbing the oil into the wood until it is completely absorbed and you can no longer see any wet spots.
- Once done, allow the wood to dry for at least 18 to 24 hours before applying a second coat or using it.
You can apply a second coat of linseed oil if needed, but it is not necessary.
But remember, if you use boiled Linseed oil it’s essential to apply at least three coats to achieve better results with your wood type. After the final coat, allow it to get dried completely for at least 3 – 4 days.
That’s too much, in my opinion. Unfortunately, there’s nothing much you can do about it because linseed oil is a relatively slow-drying finishing oil when compared to other wood oils.
7- It Enhances the Grain and Color of the Wood
Linseed oil is usually a clear transparent liquid, but it can also be a yellowish oily fluid that works to enhance the grain, color, and texture of the wood.
If you are looking to give your wood surface a deep natural look with a hint of color, using a boiled linseed oil-based wood finish is a good option. When applied to the woodwork correctly, it can bring out the natural golden colors of the wood along with luxury-rich grains of beautiful amber shades.
Linseed oil also adds a wet fresh look to both interior and exterior wood furniture while offering them a revitalizing effect to preserve for a long time.
8- The Linseed Oil is Good at Hiding the Dents and Scratches
Linseed oil also works as a popular polyphenol that helps in getting rid of watermarks, stains, cracks, dents, and minor scratches that occur on wood surfaces with time.
Particularly for wood flooring that gets a lot of pet scratches, scuff marks, and dents due to daily foot traffic, rubbing linseed oil can help vanish all these unpleasant issues while also providing the appropriate protection to the wood.
Due to its water-repellant qualities, linseed oil, when filled with small cracks in wooden surfaces, also prevents water particles from seeping in and thereby prevents the wood from further damage, such as rot.
9- It Can Also be Used as a Wood Conditioner
Linseed oil is perfect to use as a wood conditioner before painting or staining. Upon application, the surface will become saturated, and it helps prevent mistakes such as blotches or streaks.
This is pretty useful, especially if you are working on wood such as Poplar, Birch, or Pine which are notorious for being difficult to stain and finish.
Commercial wood conditioners are generally expensive, and you need to follow a special application method. But if you want to make your own wood conditioner that’s affordable, mix linseed oil with turpentine. Apply it to any wood and wait for at least 24 hours to dry before staining for the best results.
By applying a thin layer of linseed oil before staining, you will be able to stain any type of wood without worrying about moisture, blotching, or streaking.
Disadvantages Of Linseed Oil for Wood
Even though linseed oil has several benefits for wood, it also has some drawbacks that you should be aware of. Some of them are:
1- It’s Slow Drying and Time-Consuming Oil
Linseed oil is one of the slowest drying oils; it can take up to 24 to 48 hours for a single coat to dry to touch before you plan to put up another coat.
To completely get dried, it can sometimes take even 72 hours to dry because of its slow absorbing qualities into the wood fibers.
Consider the time spent on first applying the coat, lightly sanding the first coat, drying the surface, and then keep applying the second or third coat.
In short, if you are planning to apply multiple coats, it can take days or even weeks for the final coat to completely get dried and complete your project, especially if the environmental humidity is high. This can be so frustrating at times, and you might need to plan your work schedule in advance if you want to use linseed oil on your wood.
So, patience is the key when you plan to apply linseed oil on wood; without that, the end result can really get messy and tacky.
2- The Linseed Oil Yellows Over Time
One significant downside to using Linseed oil is that, with time, it will yellow slightly.
Linseed oil becomes yellow as a result of temperature variations, dampness, the kind of light it is exposed to, and excessive sun exposure. So, if the finished furniture is going to be placed in an area with direct sunlight, the linseed oil may turn yellow quicker than if it were kept indoors.
To minimize the majority of the causes of yellowing, I would recommend purchasing linseed oil from a reputable manufacturer and keeping the finished furniture in shade.
And if the finish has already yellowed, fix it by removing the old coating and applying a new one on top of it, then keep your Linseed oil-treated furniture in a covered area for better protection.
Alternatively, you can either apply sealer, wax, or color over it which will also help to prevent the linseed oil from further yellowing.
3- The Oil will Need Regular Maintenance
Since it turns from clear to yellow with time, this also means that you will need to maintain it regularly, depending on how often you use the furniture.
A single coat of linseed oil on outdoor furniture can only last for a few months before it starts to turn yellow and need another coat. For indoors, it can last more.
If you want your linseed oil finish to last, you need a minimum of 2 coats every two years.
You might think that you can simply wipe off the old coat of oil and apply a new one on top of it, but that is not the case. You need to remove the old coat completely before beginning by sanding and then applying another fresh coat of linseed oil.
4- No UV Resistance and is Not a Very Durable Finish
Linseed oil is an oil-based product, and it does not have any UV protection properties due to the lack of UV filters or UV pigments that can avoid the sun’s harmful rays from going inside the wood.
Additionally, exposure to UV light may also sometimes promote the growth of insects along with cracking and splintering on wooden surfaces that have been treated with linseed oil.
So if you are planning to use it on outdoor furniture, know that it will not be a good option as the finish will eventually start to degrade when placed under direct sunlight for extended periods.
5- Linseed Oil Supports Mildew Growth
Since linseed oil is not very rigid, it supports the growth of fungus, molds, and mildews, especially in high-humidity conditions.
So, if you can, it’s recommended to keep the Linseed oil-coated furniture in a dry place with good air circulation to avoid such problems.
Also, to stop the unpleasant mildew growth on the linseed oil film, you should never apply the oil in very thick coats. Instead, apply it in thin layers and wipe off any excess before it has a chance to dry on the surface.
6- Linseed Oil is Susceptible to Water Rings and Stains
Linseed oil is a soft, natural finish that can be applied to wood to protect it from water and other liquids. Yes, the oil is water-repellant. However, because the linseed oil finish is not very robust and not waterproof, it can be easily damaged by water.
Especially if you place glass or bottle of cold water on oil-finished surfaces, watermarks can be created that can be challenging to remove. To avoid this problem, you should always use coasters or mats under glasses and bottles to protect the finish from water damage.
Also, to avoid water rings and staining problems with linseed oil finishes, it’s good to wipe off the water spills as soon as they happen. If the water stays there and gets evaporated from the surface, it will tend to leave behind lighter color rings on the surface.
7- The Oil Has a Bad Smell that Takes Time to Fade Away
Linseed oil has a very distinct, strong, unpleasant smell when first applied. The odor is caused by the evaporating solvents in the oil and can be quite overwhelming.
Applying linseed oil on wood surfaces is, therefore, a stinky job for most who are sensitive to foul smells.
The good news, however, is that the smell does eventually fade away with time as the oil dries and hardens on the surface. It may take a day or two for the smell to completely disappear, but it will go away for sure.
A Few Additional Tips for Linseed Oil Application on Wood
Now, once you know all the advantages and disadvantages of linseed oil, you may get ready and start applying it to your wood surfaces.
But before doing that, here are a few dos and don’ts you should keep in mind…
a) Never apply the oil to wet wood
Applying Linseed oil is only successful when the wood it’s being applied to is dry; applying it to wet wood will result in blotches and bubbles and generally ruin the furniture’s appearance.
b) Apply the oil to bare unfinished wood
Linseed oil works great on bare oak and furniture made of other unfinished wood boards like MDF, particleboard, and plywood. You can also apply it to wood that’s previously been treated with a water-based finish like latex or acrylic paint to give it a nice lustrous sheen.
But do not apply linseed oil on wood treated with oil-based paints, stains, or varnishes because they both don’t mix well and can cause blotchiness.
c) Use wax or paint to add extra protection or color
The linseed oil finish on the wood is paintable but not stainable. This means you can paint over it to change the color of your furniture if you desire.
Or, if you want to achieve a darker tone on the wood, you can apply a coat of dark wax over the oil evenly and smoothly. The wax will also help to add extra protection to the wood and make the surface more durable.
The bottom line
Linseed oil is a great natural product to use on wood surfaces. It’s easy to apply, it’s environmentally friendly, and it gives the wood a beautiful lustrous sheen.
However, there are also some disadvantages of using linseed oil that you should be aware of – like the oil is susceptible to water damage, it has a strong smell when first applied, and it can take some time to dry and harden completely.
Keeping these things in mind, you’ll be able to successfully apply linseed oil to your wood and achieve the beautiful finish you desire.
Jack Luis is a semi-retired painter who loved painting his clients’ ideas on their walls.
He had worked as a painter for over a decade serving customers in areas such as Charleston, Mount Pleasant, Beaufort, and Georgetown, SC (South Carolina). Today in his free time, he likes to read and write about the newer techniques implemented in his profession. You may read more about him here or get in touch with him here.