How To Stop A Crack In Wood From Spreading

ooga booga and wood split

I have a small totem pole I inherited from my grandfather. He made it after he retired from being a marketing executive. It has started to develop a massive crack in the wood.

My journey to fix this crack, led me to write this article. Here is what I learned as I stopped the crack from spreading in this heirloom piece. Here is how to stop a crack in wood from spreading.

Cracks can form on the surface or inside the wood, and they are usually caused by external factors such as water or heat.

What Causes Wood to Crack?

Wood cracks can be caused by a variety of reasons, the most common being moisture. When rain seeps into the wood, the moisture causes the wood to expand. As the wood dries out again, it contracts, leading to a crack in the surface. In order to prevent this from happening, it is important to follow proper guidance and treatment when working with wood.

These cracks can also form when furniture is made from lumber that has not been properly dried. After the furniture is finished, it continues to dry, causing excessive shrinkage and a crack.

The heating and cooling cycles in a home also cause wood to crack. During the winter, the heater kicks on, drying the humidity out of the air. As the air dries, it pulls moisture from the wood.

Moving the affected piece of wood away from the heating source can help. 50-55% humidity is best for preventing cracks, and it may require a humidifier to maintain your house at this level.

If a crack does form, it can be filled in with wood filler or glued together with wood glue. Once it has been fixed, it will need to be sanded smooth and finished off with a sealant or paint.

Sealing furniture is important. In the case of my table above, the top of the table had sealant applied. However, the ends and the underside of the table was not sealed. This led to water evaporation and subsequent cracking.

And if you see a cracked piece of lumber, then you should not start working with it. Wood that is properly kiln dried is less likely to have cracks occur in the drying process.

How To Stop A Crack In Wood From Spreading

Option 1: Wood Glue and Clamps

Carpenter screw clamp tools pressing wood slats ang white glue

For small cracks, start by sanding around the crack with a fine-grit sandpaper. Then, fill the gap with regular PVA wood glue. Squeeze the glue in until the glue fills the entire crack.

From there, apply a clamp, to push the wood back together. Wipe the excess wood glue away and let it dry in the clamped position for 48 hours.

Once it is dry, seal the outside with a new layer of paint of urethane sealant to prevent cracks in the future.

Option 2: Easy method use of wood filler or wood epoxy

Putty knife in man hand. Removing holes from a wood surface. Preparation of boards before impregnation with varnish.

If the crack is not fixed, it can continue to grow and spread, causing further damage to the wood. Wood filler can be used to fill in these large cracks and restore the wood to its original condition. Wood glue (white glue) is also a useful material for repairing smaller cracks in wood; However, if the crack is too large, step up to wood filler.

If the crack is too large, you will not be able to squeeze the wood back together with clamps. Instead, your goal will be to stop a crack in wood from spreading.

The first is to use wood filler or wood epoxy. Wood filler is easy to use and is the best option for most cracks.

(Note: Wood putty is not good for cracks, since it is just talcum and coloring. It does not bind the wood, just masks the crack. Wood putty is more suitable for small things like nail holes. I have an article comparing wood putty and wood fillers.

Epoxy is better for thin cracks, while wood filler is better for medium-size cracks. If you plan on sanding, painting, and/or staining your project, wood filler is the better choice.

First, apply masking tape underneath the crack to hold the filler as you apply it from the top.

Apply the filler material liberally to the crack. It will initially look uneven and ugly. However, it is better to have too much filler than not enough. After it is dried, sand all the excess filler away until you have a flush, flat finish.

There are many different types of wood filler available on the market, each with its own specific properties and applications. Once the crack has been filled in with wood filler or glued together with wood glue, it will need to be sanded smooth and finished off with a sealant or paint.

Option 3: Sawdust and Glue

The sawdust and glue method can be a cheap alternative to wood fillers. By mixing sawdust into wood glue, you create a hardened binder that can stop cracks from spreading.

The advantage of sawdust is that you can use sawdust from the same species of wood and get a coloration that more closely matches the damaged wood. Additionally, the cost on this is a lot less than when using wood filler.

If the crack is through the wood, epoxy would be a better choice.

How to apply sawdust and wood glue in wood cracks

sawdust and pencil with jigsaw

There are three simple steps to follow in order to repair a cracked wood with sawdust and wood glue:

  1. Prep the area by sanding and blowing the area clean with an air compressor.
  2. Get your sawdust and wood glue ready.
  3. Mix the sawdust and glue together.
  4. Press the sawdust and glue into the crack with a putty knife. Press down on the sawdust so that it adheres well to the crack, and then let it dry overnight. The surface of the wood should be clean before you start repairing it, otherwise, the glued-on sawdust will not stick properly.
  5. Finish by rubbing more sawdust across the crack to completely cover the area.

Allow it to dry for at least a day before sanding down any rough edges. Stain as desired and then apply resin/hardener to the wood before giving it time to cure. Finally, apply another coat of sealant or paint.

Option 4: Filler Compound

image of wood filler used on table with red circle

Using a filler stick or filler compound can be an easy way to fill small cracks. However, these do not have the binding properties of wood filler, and so they are less likely to stop cracks spreading.

However, they are much easier to use. You can simply push a filler crayon into the wood and reseal over the top of it (some discoloration may occur).,

For small blemishes, this might be a suitable option.

Final Step: Apply Sealant or Stabilizer

Another most common way for stopping cracks is to apply sealant or stabilizer. This will help to keep the wood together and stop the crack from spreading. You will need some basic equipment, including a paintbrush, wood slices, and protective gloves. Be sure to follow the instructions carefully and allow the sealant or stabilizer to dry completely before using the piece of furniture or structure.

Use Varnish

Varnish is a sealant that is applied to wood in order to prevent it from splitting. It is a clear, protective coating that is usually applied after the wood has been stained or painted. Varnish can also be used to protect furniture and other wooden objects from water damage and fading.

Apply Paintable Wax

One way to protect greenwood from splitting and cracking is to apply paintable wax. This can be done by melting wax candles with paint thinner in a saucepan. The wax should then be applied evenly to all open ends of the wood with a brush and allowed to dry.

Apply Boiled Linseed Oil

Boiled linseed oil is a sealant that can be used to protect the wood from splitting and cracking. It should be applied in thin layers so that it dries quickly. The oil should also be dried between coats. Boiled linseed oil will help to guard the wood against splitting and cracking.

How To Keep Wood from Splitting When Nailing?

There are a few ways to prevent the wood from splitting when nailing. One is to turn the wedge into the punch and hammer it before inserting it through the nails. This will help create a space between the wood and nail, which will help reduce splitting.

Nailing in close to the same wood grain line can also help avoid splitting. Additionally, using a lubricant (petroleum jelly) when nailing can reduce friction between nail and wood, making it easier to drive the nail in without causing splits.

Finally, always use nails with a smaller diameter, as they are less likely to cause splits than nails with a larger diameter.

How To Keep Wood from Splitting When Sawing?

When sawing wood, there are a few things you can do to help prevent it from splitting. First, keep the saw blade moving slowly and avoid adding excessive pressure. You should also use a sharp blade and make sure the wood is properly aligned with the blade before cutting. Finally, always cut in the direction of the grain whenever possible.

How To Keep Wood from Splitting When Drying?

Wood can split when it is dried, nailed, or sawed. This is a common problem that can be prevented by taking a few precautions. When wood is dried, it can split if the moisture content is too high. To prevent this from happening, make sure the humidity level is low, and the temperature is constant.

Nonetheless, there are several ways to prevent the wood from splitting when drying. One way is to use a sealant or stabilizer on the wood before you start to dry it. Additionally, you can avoid splitting by making sure the wood is not too damp and taking care when you’re sawing or nailing the wood. Finally, be conscious of the humidity levels in your area and adjust your drying schedule accordingly.

How do you fix a hairline crack in wood?

There are a few ways to fix a hairline crack in the wood. The two most popular methods are using wood filler or epoxy. Wood filler is good for cracks that go around the wood, while the epoxy is better for widened cracks. Epoxy will seep through the crack and bond with the wood, while wood filler takes longer to dry.

How to stop a crack in the wood table from spreading?

If the crack in the wood table is at the center then you should try glue, wood filler, epoxy resin. If the crack is on the edge, then it is better to cut it out. Sometimes for the cracks in the tabletop, you can remove the wood part completely and put in a new wood board there.

Will linseed oil stop wood from cracking?

Boiled Linseed oil acts as a seal to the crack. The application of boiled linseed oil is also very easy. However, you will need to sand the wood before applying the oil. Also, you can not expose the wood to sunlight at this stage.


While the most common way of fixing cracks in woods is filling them up however you will see yourself fail sometimes. Everything does not work every time. And sometimes replacing the wood is the best choice to do.


Zachary Drumm

Hey! My name is Zachary Drumm! This site allows me to test new tools, piddle around in the garage, and share the insights I get from flipping cars and houses. When it comes to tools, home improvement, and being a “shade tree mechanic,” you’ve come to the right spot. If I’m not in the garage creating content, you’ll find me outside, running, canoeing, and traveling. My goal is to empower more people to be self-sufficient.