Home » How to Fix Split Wood? A Comprehensive Guide

How to Fix Split Wood? A Comprehensive Guide

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Cracked wooden pieces get thrown away frequently because the owners do not know any better. Losing your favorite furniture or antique material because of a little split is frustrating. But do you know cracked wood can be repaired and made to look like new?

Not all splits are indeed restorable, but you’ll be surprised to realize that many can be repaired. Instead of discarding the wood, take some time out to consider the possibility of fixing the cracks.

It is easy to fix cracks on chair legs, table tops, and headboards once you understand the restoration process. If you have a split wood and want to mend it, our expert advice as we highlight a detailed restoration process. But first, why does wood crack?

Why Does Wood Split?

Why Does Wood Split

First, understand why wood cracks and then use that information to choose the best solution. When your wooden piece cracks, it loses integrity and efficiency. In this section, we’ll see why your wood splits.

1. Inadequate Moisture Level

Moisture is the leading cause of wood splitting, as variations in moisture levels can crack the wood. Contraction and expansion occur due to unbalanced moisture levels; this movement in the wood structure makes it split.

The moisture in the wood and atmosphere must match; otherwise, the wood would expand or contract when balancing the moisture. Timber placed in moisture-prone areas like bathrooms and open spaces are susceptible to splitting. It is the same with wooden pieces in an environment with fluctuating water levels.

2. Nailing and Screwing

Nailing and Screwing

When the wood is too dry, splintering due to nailing or screwing is expected. Driving nails into the wood exposes the structure to heavy pressure, leaving cracks in the lumber. The nails create spaces between the tightly packed wood structure and may splitter.

Improper nailing or screwing where the nails move out of the joint is another reason wood splits. The movement around the joints may also put pressure on the screws. It can crack if you’re nailing close to the wood edge because the structure has minimal support. Many woodworkers use poor nailing techniques that force the nail out of its initial path.

Materials Required

Before learning how to restore cracked wood, you must gather all the supplies needed for the process. The materials and tools for this repair are typically easy to get, but you shouldn’t take our word for it; check them out. Depending on the method, here are some of the materials and tools you should gather:

  • Clamps: manually holding two pieces firmly for a long time can be challenging and sometimes impossible, but the clamp makes the process straightforward.
  • Paint/Stain: Repairing the wood involves restoring the paint or finish used on the surface and covering the crack lines.
  • Sandpaper/Sander: You’ll need suitable grit, which may include medium to fine-grit levels. Sandpaper removes the wood’s top layer, smoothens bumps, and helps finish after repairs.
  • Wood Filler: The filler covers holes in the wood, is fast-drying, and is easy to use.
  • Wood Glue: Joining broken pieces together cleanly is straightforward with wood glue.
  • Bondo: This type of wood filler covers cracks and holes in the wood.
  • Putty Knife: Applying the wood putty or filler is easier with a putty knife as it can reach tricky corners.
  • Paintbrush: if you want a seamless paint, stain, glue, or sealant, use a paintbrush.
  • Hardener: You can reduce your work time and make the fix dry faster by combining the filler with a hardener.

Step-by-Step to Fix Split Wood Using Wood Filler

Step-by-Step to Fix Split Wood Using Wood Filler

The method for fixing splits in your wooden piece varies significantly; some are straightforward, while others require a higher skill level. We’ll highlight a detailed step-by-step guide you can use with minimal experience.

We’ve chosen wood filler for this guide as it is accessible, easy to use, and affordable. You’ll find many more advantages wood fillers have over other materials. The steps are also helpful for wood putty with minor differences in their preparation.

Remember that this method suits superficial cracks with visible insides. Large holes or tiny cracks may require other repair processes. After gathering your supplies, you can proceed to the steps below:

Step 1: Choose the Appropriate Filler Hue

You want to repair and restore the wooden piece so the gap is no longer visible. To achieve this, select a wood filler with the same hue as the wood you’re fixing. You can even mix more than one hue to get other colors. Brands have options to choose from for the perfect blend.

Step 2: Mix with Hardener

Step 2: Mix with Hardener

Combine the wood filler with a hardener if you want the filler to dry in minutes. Mix the two-part filler on a solid surface like a scrap tile while ensuring you combine only the quantity you need. The hardener typically comes in small tubes; only a tiny amount is required for small to medium-sized projects.

Use the putty knife to mix the hardener and filler on the mixing surface. The ideal ratio is a pea-sized hardener to a scoop of wood filler.

Step 3: Apply the Mix

Use your finger or putty knife to apply the filler mixture to the crack. The aim is to push the filler into the gap and avoid air bubbles by pressing into the mix. Fill the crack, but keep the bump to a minimum to make sanding easier.

The putty knife also helps to smoothen the filler and remove excess on the wood surface and over the crack. Leveling the mix before it sets is essential, as dry filler is harder to shape. However, it is not impossible, as you’ll see in the subsequent steps.

Step 4: Allow to Dry

Step 4: Allow to Dry

Wood fillers typically take up to 8 hours to dry, which can prolong your work period. However, the drying period is significantly reduced when the wood filler is combined with hardener.

Step 5: Sand

The crack is covered at this stage, but the surface may typically carry some bumps. Repairing cracks should not be at the expense of aesthetics, so refining its look is vital. And sanding is the best way to smoothen and level the filler.

Depending on the size of the project and available resources, you can use a sander or sandpaper for this process. Sander is easier to use but is suitable for large, flat surfaces. On the other hand, sandpaper will reach corners and smoothen curves.

Use your chosen material to sand the wood filler along the grain so it is level with the wood surface. It would help to start with medium-grit and then fine-grit sandpaper for optimum finish.

Step 6: Apply Finish

Step 6: Apply Finish

Restoring cracked wood is complete once you’ve covered the area worked upon. Although applying the desired finish is the final step, it is just as important as any of the above processes. But before you start the restoration, wipe off the dust from the sanding using a rag.

What is the best way to get an exciting finish? Choose the same finish used in other wood parts, including the stain, paint, sealer, or varnish. The aim is to blend the area with other parts of the wood. Use the appropriate applicator and follow the manufacturer’s instructions to apply the finish.

How to Stop Wood From Splitting?

How to Stop Wood From Splitting

Learning how to repair split wood is vital, but prevention should always be given preference. After going through the process, you will understand why fixing cracked wood is frustrating, time-consuming, and expensive; prevention is way easier. Here are a few ways to avoid splitting wood:

1. Applying Stabilizer or Sealant

Covering the wood with a coat of stabilizer or sealant will stop the sudden moisture transfer between the wood and the atmosphere. The wood will not shrink or expand, which is a leading cause of cracking.

It is easy to use this method as the sealant does not affect the aesthetics of the wooden piece. Also, you don’t need to purchase special tools to apply the sealant or stabilizer.

2. Properly Store the Wood

Properly Store the Wood

Improperly stored wood will crack before use. Other times, the split happens when a nail or screw is driven into it. This is why it is vital to follow wood storage best practices to prevent cracks. Some of these best practices include keeping the wood away from extreme temperatures.

You also want to keep it from direct sunlight and away from moisture. Insects can also attack your wood if stored in the wrong location. Proper storage is simple but has a significant positive effect on the wood.

3. Coat with Boiled Linseed Oil

Covering your favorite wooden pieces with boiled linseed oil is a suitable way to prevent cracking. The boiled linseed oil acts as a seal on the wood’s surface. You’ll need a paintbrush to spread the oil on the surface evenly.

4. Apply Paintable Wax

Apply Paintable Wax

Wood coated with paintable wax will not crack due to the wax’s protection. It is easy and affordable but effective in preventing splitting. Here’s how to make a paintable wax to protect your wood: grind it, melt it over a heat source, and mix it with a paint thinner. Apply around the wood to seal the surface. You can also paint over the wax without issues.


While the steps highlighted here are easy to follow, some confusion can arise about other aspects of repairing wood splits. Check this section for some popular questions and answers.

Q1. What are the different types of wood fillers?

Ans: The different types of wood fillers you can use are putty, bondo, spackle, and epoxy.

Q2. How long does it take for wood glue to dry?

Ans: The average wood glue drying time is 24 hours, with the exact time dependent on the product and environmental conditions.

Q3. Can I use wood filler on wet wood?

Ans: Wood fillers are ineffective on wet wood, so wait for the wood to dry before adding fillers. The filler will not dry out and adhere to the wood when wet.


Cracks on your wooden piece shouldn’t spell the end of it, as repairs are possible. Adequate restoration can make the wood look new; however, the proper process must be followed to succeed.

There are many methods, but wood fillers are famous for their ease. You can use various wood fillers, like Bondo, sparkle, putty, and more.