How To Fill Wood Cracks?

Cracks are among the most common problems with wood, whether wood slabs, sheets, boards, or planks. They are mostly unavoidable even with the best wood cutting tools and even with proper handles. You should know how to fill wood cracks if you want to give that lovely finish to your product.

how to fill wood cracks

Wood cracks are unappealing and can also affect the final product’s integrity. Worry not as there are plenty of ways to save a damaged piece of wood depending on how large and deep the gouge is, the type of wood, and the purpose of the wood.

For instance, if a wood plank is to be used in furniture, cracks should be filled up in a way that the overall aesthetic is restored. The use of wood fillers or glue-plus-sawdust can be a useful technique. Meanwhile, if a cracked wood is to be turned into an artistic furniture piece, polymer resin or glass can be used to cover up the crevices while adding colorful, artsy flair.

There are different ways on how to fill wood cracks. Let’s check out below.

Commercial wood fillers

Wood filler sticks and wood putty are among the most popular ways to repair cracked wood. Not only are they easy to use, wood putty is very effective for covering wide cracks in your wood. It’s a workshop essential. Every woodwork enthusiast need to have wood fillers in their workshop.

Wood fillers and putties come in different brands and formulation. Usually, fillers are available in oil base, a lacquer base, or water base. You need to use appropriate product that will adhere to the type of wood for a successful wood repair.

Among the three types, lacquer based fillers are the most versatile. They can be used with almost any wood finishes. However, these fillers tend to dry hard and eventually shrink and crack. On the other hand, oil based fillers dries longer and might not be compatible with other finishes. So, you have to make sure what finishing product you’ll use when picking fillers.

If you need a fast-drying wood filler, then latex based fillers are your best bet. They also lack the disadvantages common with oil- and lacquer-based fillers. Latex base fillers are compatible with different types of film finishes. For deep cracks, clean the area thoroughly, and remove any debris and loose material. Fill up the gap and smoothen up with some sandpaper. Gradually apply several layers of coating, allowing each layer to dry completely before adding new layer. If you apply one thick coat, the filler won’t dry up properly and eventually shrink and crack. Once the crevice has been fully filled up and the coating has dried up, sand it until smooth and the desired surface is achieved.

There are colored and stainable commercial latex fillers that you can use. Pre-tinted fillers come in different wood colors such as walnut and maple. You can definitely find filler colors that closely match the wood. If using a unique wood gradient, you can use stainable fillers and paint it up with stain that matches the wood.


When it comes to large and deep cracks, commercial fillers might not suffice. Epoxy is best used in these cases. Two-part epoxy produces mixture that dries hard without shrinking or cracking. Once it settles, epoxy can be worked on just like natural wood. The downside with epoxy is that it produces a clear finish that can look unappealing especially in stained wood. As an alternative, tints and pigments can be added into the epoxy mixture to achieve the natural wood color. These colorants can be found in paint stores or art supply shops. Epoxy produces a sticky mixture that tends to look messy and difficult to clean up. Be sure to work carefully on your woodwork project to avoid unwanted stains.


For wedge-shaped, narrow cracks, you can use wood splinters to fill up the void. Get a scrap wood. Split or shave thin splinters. Coat the splinter with glue and insert it into the crevice. Push the splinter firmly into the crack using a screwdriver or any similar tool. Don’t exert excess pressure to the wood as it might break the wood fibers. Splintering is best used for harder wood types with larger gaps. However, be sure to use similar wood type for the splinter, or else, it will look obvious.


For minor dents or cracks, steam can help restore the wood’s integrity. With this technique, you just need wet cloth and clothes iron. Place damp cloth over the damaged area. Set the iron to its highest setting and place it over the damp cloth. Let it steam for at least three seconds. Heat causes the crushed cells to expand fully covering minor cracks. This is quick fix can saves you the need for wood filler. Once the wood has been steamed up, it can be sanded again to flatten out the raised grain.

Sawdust and glue or finishing product

Another easy wood crack repair is by using a mixture of sawdust and glue which is perfect for small gaps, crevices, and imperfections. Collect enough sawdust from a nearby woodworking shop or create your own using a fine-toothed rasp or coarse sandpaper. Be sure to use sawdust from the same wood type. Mix glue and sawdust until putty consistency is achieved. Fill up the crack with the sawdust mixture. You can use fine stick or toothpick to fill up narrow crevices. Wait for the filler to dry up and then sand the top surface. This crack repair technique is effective for wood application with solid color and for very minor cracks. Alternatively, you can add finishing product with sawdust to cover up imperfections.

Polymer resin

Polymer resin can likewise be used for filling up wood cracks. It comes as clear, sticky liquid but you can also add tint to mimic the wood color. Usually, polymer resin is used for woodworking projects with aesthetic finishes. The polymer resin can be sanded until glossy, just like glass. Combining resin and wood produces amazing effect.

There are tons of products and techniques to repair wood projects. With the right technique, it’s easy to mask any type of wood crack!

Author: John Clax

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