How To Harden Wood? How To Increase Durability By Wood Hardener?

Understanding the properties of wood, consumers can maximize the use of this natural material. We can also overcome the drawbacks of furniture and increase their durability.

Base on the characteristics of the wood, we can choose which wood to use for each proper context. Wood may be cracked, termite, warped or decayed over time. Therefore, protecting and preserving wooden products is not a simple task.


Poor wood processing will counteract the effect of wood. When wood is exposed to the disadvantages such as weather sensitivity, deformation, warping, and shrinkage or cracking. The way to overcome is to know how to harden wood, wood hardener

Why have to harden the wood? Is it possible to harden wood?

Usually, softwood can be used as home furniture, such as tables, chairs, beds, cabinets, etc. But hardwoods must be used for stairs, floors, and places where work is most common.

 According to interior experts, using the right wood will increase the durability of wood over time. For example, if we use softwood for stairs, the wood will break, crack and be unstable.

In combination with other materials, one must be aware of the stability and deformation of the wood, which can withstand the accompanying elements.

Wood is one of the priority materials when selecting furniture in the home by elegance, proximity and friendly with nature.

We need to know how to use them to enhance the beauty of the home as well as extend the life of the wood.

How To Harden Wood – 4 Ways

Do you know that sometimes, wood that seems to be disposable as it is soft and rotted can become hardened and useable? If you understand how to harden wood properly, it can be firm enough for fixings as well as become good in structural integrity.

Take a look at the tips below for some suggestions on four of the most effective methods you can use to harden a piece of wood.

  1. Using the method of fire hardening wood
  2. Using A Strengthening Epoxy
  3. Using Polycryl
  4. Using wood hardener

Is it worth hardening of a piece of wood?

Sometimes, a piece of wood is not exactly worth being hardened at all. So you need to check before you choose to harden any wood piece.

You must use your hand to lift any loose piece. If you can find it easy to do so, it is not worth keeping and hardening this kind of piece of wood at all.

In case you find it hard to remove any loose piece of wood or it couldn’t afford to do all.

Besides, in case the piece of wood is so soft, you can harden it for your better future woodworking project. How to harden wood? Here are all of the methods that you can do to harden the wood

1. Using the fire hardening method

This is one of the most common methods you can apply to harden a piece of wood. This method is known as the fire hardening. Although it is called this way, people use the element to harden the wood is not the fire, which is the heat.

The heat coming from the fire shall extract the moisture getting out of the piece of wood. The wood grain of the piece of wood will be tightened as a consequence.

This method is quite hard to use because you must be extremely careful to protect yourself from getting burned. Also, too much heat will damage such piece of wood that you should apply proper amounts.

You mustn’t put the piece of wood too close to the heat and for a long time; otherwise, the piece of wood can scorch or burn.

The key advice to this method is that you should be very patient. You must even try several times before you can adequately master this technique. The fire-hardening method should be used for making spears or arrows.

Here are all of the steps for you to follow to harden wood with fire:

Step 1: Prepare a fire pit. You can dig a hole if you don’t have one; place some rocks inside as well as pieces of charcoal in the middle.

Step 2: Light up the charcoal. Slowly and gently blow into the pit to get the flame to become bigger.

Step 3: Continue to throw some small pieces of charcoal into the fire and wait until the flame is stable enough. The best flame you should aim for is the one that is 6 inches high. It must also have a blue center.

Step 4: Hold the piece of hardened wood over the flames for a few minutes. Make sure that you mustn’t put the piece of wood too close to the flame. You should maintain a gap of around 3 inches between the flame and the piece of wood.

Step 5: When an area of the wood piece gets just a little bit warmer, it’s necessary for you to turn that piece of wood around. Then, you should change sides of the wood immediately to avoid a particular area from being overheated.

Step 6: After you finish step 5, stop in a while to check the situation of the piece of wood. If the surface of such piece of wood looks dry, then it means that all of the moisture is extracted. Such piece of wood is now harder than before.

Step 7: Place this piece of wood to cool down in a cool dry place. And now, you finish hardening a piece of wood by using the fire hardening method.

You can watch this video to know more:

2. Using A Strengthening Epoxy

You can apply the method of strengthening epoxy to the surface of the wood piece that you recognize the fibers of a piece of wood become loose. It aims to make sure these fibers remain bound together.

After you finish applying the strengthening epoxy, you can even hammer it with nails and do everything just like what you do with firm and compacted pieces of wood.

This method is easy to follow, even for an amateur at woodworking. The strengthening epoxy is also widely available. However, for large pieces of wood, it shall take you several days waiting for them to reach the hardness that you want.

Applying epoxy not only make your wood portion harder but also more good-looking. Source:

Applying epoxy not only make your wood portion harder but also more good-looking. Source:

Here are all of the procedures you need to do to harden wood by using a strengthening epoxy product:

Step 1: Firstly, you need to remove all of the dirt and trash on the surface of the piece of wood. This step shall prevent them from sticking firmly and permanently on the surface of the pieces of wood after when you apply the strengthening epoxy.

Step 2: Mix the ingredients of the recommended ratio of strengthening epoxy from the manufacturer in a bowl. Each strengthening epoxy should have a different ratio and way to mix with water. Thus, you must follow the instructions carefully to achieve the desired results.

Step 3: Stir the bowl well so that all of the ingredients are mixed. Continue to stir until the liquid becomes thicker. Don’t use the liquid when it becomes only as thick as glue. However, the thicker liquid like paste won’t be sufficient.

Step 4: Next, use an applicator brush and apply a layer of the mixture onto the wood. Evenly spread the mixture over the soft section that you want it to be hardened.

Step 5: Wait for the strengthening epoxy to deeply penetrate the piece of wood and the remaining solvents to dry up. While a small part of wood only takes just a few hours; a large portion takes even up to a few days.

Step 6:  You might consider adding more layers of strengthening epoxy to a much harder piece of wood. When the first layer dries, apply other layers after the steps above.


When you apply the strengthening epoxy onto the surface of the wood piece, you should use as much as you can.

In case you get a very soft piece of wood, you should drill a hole into the middle of the wood and then fill it with a strengthening epoxy. You can apply the same case as a large piece of wood. By this way, the epoxy can penetrate quickly into a large area of the wood.

As mentioned above, it shall take quite a long time for strengthening epoxy to penetrate and the solvent to dry up. You can speed up this step by placing the piece of wood you are working in a dry place.

Temperature is also a key factor here. The lower the temperature is, the quicker the strengthening epoxy can penetrate to harden your piece of wood.

3. Using Polycryl

Polycryl (see here) is a form of wood improving method that helps to harden a soft area of a piece of wood. This method is safe, cheap and easy to use. Besides, it is also a safe product.

After when a piece of wood is hardened by this product, the appearance of the wood shall not be altered.

Follow all of the steps to harden a piece of wood by using Polycryl:

Step 1: Mostly when you buy Polycryl in the market, it is in the concentrated form. Then, you need to dilute it with water. You should follow the instructions on the label for the recommended ratio of Polycryl and water. Mix water and Polycryl in a bowl and then stir well.

Step 2: Remove all of the dirt and debris from the surface of the wood. This step is considered as surface preparation to prevent these particles from permanently sticking onto the wood.

Step 3: Use an applicator brush and then deepen it into the mixture of Polycryl and water.

Step 4: Then apply a thin layer of Polycryl onto the desired areas.

Step 5: Place the piece of wood aside in a dry and cool place. Wait for several hours for the solution to deeply penetrate the piece of wood.

Step 6: After step 5, you must continue to apply more Polycryl until when the piece of wood reaches the desired hardness.

For a small piece of wood, you can apply the above steps. For a big piece of wood, you can deepen the entire piece into the Polycryl solution.

4. Using Wood Hardeners

If you’ve got an old wood piece, deck or column that is starting to show signs of age, there is one way to stop the decay that is using a wood hardener (See Mixwax Wood Harderner).

This product penetrates the pores of the wood, and it shall become hardener. Wait for two or four hours, continuing to keep the wood intact.

Step 1: Identify the area on the wood that you want to harden. Prepare the wood piece by scraping away any loose or decayed wood by using a putty knife. Keep on working until you get the desired shape of the wood piece. Make sure that there is no grease, oil or dirt in the desired area.

Step 2: Shake a can of wood hardener. After a while, pour a little of the hardener onto the surface of the wood piece and then, spread it out around the area by using a paintbrush.

Step 3: Apply a second and third coat by using the paintbrush for extra strength, and then, applying coats until the wood gets a shiny surface.

Step 4: Let the wood hardener dry from two to four hours. You can sand, paint or stain the surface to finish the project.

Final thought

The use of furniture made from wood is the good choice of many people today. The use of furniture made from wood produces a number of problems. In fact, although the wood furniture is strong, but in the process of using furniture, there are still some problems such as wood warps, termites, or cracks.

Hope that after the article, you can know how to harden the wood, wood hardener and other methods to help increase the lifespan of wood.