Filling Wood Cracks with Colored Epoxy 2022 – Guide

Filling Wood Cracks with Colored Epoxy is a common design situation in woodworking, especially if you are outsourcing raw wood logs or even if you are making the wood yourself. Cracks in wood are not aesthetically pleasing and compromise durability and strength when used in woodworking. Are you in search of the step by step (with no step skipped) process and reasons for Filling Wood Cracks with Colored Epoxy? Then kindly read the article below till the end for the full reveal.


Wood cracks are raptures, splits, or separations in wood grain, which often reduce the quality of wood in terms of appearance, strength, and functionality.


There are several theories behind the mechanism of the cracking of wood. For the sake of this article, we will go by the commonest theory of the internet, which relates wood cracking to wood shrinkage as wood dries. Wood shrinks twice as much along with the growth rings as it does across the rings, and it is this unevenness that is responsible for the wood cracks.



Wood cracks are unsightly because they are often of a different texture, color, and pattern from the overall appearance of the underlying piece of wood. Therefore, wood cracks are unlikely to be beneficial to maintain the beauty of your woodworking project. Also, wood cracks make slit depressions in wood, which cannot be used as is due to the settling of dust and insects when in use. Therefore Filling Wood Cracks with Colored Epoxy becomes crucial to beautify the look of wood cracks and enhance woodworking aesthetics.

The best advantage of using colored epoxy is the limitless array of colors that you can incorporate in epoxy resin, giving the possibility to add up to 16,000,000 colors.


Wood cracks reduce the overall strength of a piece of wood due to the inconsistency in the length of the wood piece. By interrupting the length of a piece of wood, then the integrity of the strength of the wood piece is compromised. In addition, pressure on a cracked piece of wood causes sagging and, as such, is not ideal for heavy-duty works. Therefore Filling Wood Cracks with Colored Epoxy becomes crucial to improve the strength of wood. Epoxy resin bonds with the surfaces of wood to form a high-strength result surface that is stronger than cracked wood.


Sometimes wood cracks occur in inconvenient places. For example, a wood crack could occur in the middle of a long piece of wood. If a woodworker was in search of a single, long piece of wood, then the wood crack is responsible for leaving the wood piece to go for another continuous non-cracked wood piece. If the wood crack occurred at the end of the piece of wood, the wood crack could be ridded away using sawing, but this way, there is wastage of wood resources.

In another perspective, by increasing both the functional and aesthetic quality of wood through Filling Wood Cracks with Colored Epoxy, one is able to perform more woodworking projects because the engineered wood cracks can now fit in a wide range of design situations.


Here we shall outline and discuss simple steps that you can follow to Filling Wood Cracks with Colored Epoxy. We shall also give you the best materials you will need for this process. Therein we shall throw in all the tips in our arsenal to make the process smoother. Be sure to follow the steps below to the letter for optimal results.

DISCLAIMER: Each Colored Epoxy System has its specific instructions, sometimes special detail, and as such, we recommend reading the product instructions before attempting this exercise.




Wrestling Mat Tape


Best Epoxy for Filling Wood Cracks with Colored Epoxy



Blow Torch

Heat Gun

Cyanoacrylate glue



The very first step in filling wood cracks with colored epoxy is to clean all of the debris inside of the wood cracks. Then, remove all the loose material you could be having to reduce the degree of potential bubbling that could negatively affect the final results’ aesthetics. Some of the debris will be punky wood that rots or fine sawdust.

Sometimes you might be forced to use lower instead of brushes since wood cracks at times could get too narrow for brushes to fit.

Failure to take perform this step carefully makes the epoxy cure with debris on the surface.


To start, flip the voided wood piece over to access its bottom side. Find any of the knot holes, cracks, or voids that show to this bottom side and tape them off. Taping these voids on the bottom side allows the epoxy to avoid leaking that would otherwise cause sunken epoxy surfaces or mess the workshop floor surface. It is crucial to tape all of the bottom cracks regardless of their size since it could be leading to a big crack on the top side.

You want your tape to be a wrestling mat tape that is quite flexible and holds on to the surface phenomenally well as to require significant pressure. This feature is very well suited for the huge pressure on the bottom by the high amount of epoxy needed to fill cracks in the wood.

When it comes to filling wood cracks with colored epoxy, it’s not a worthwhile adventure to run a series of tape wrap across the bottom of the void. This way, one ends up creating many planes of weakness through which the epoxy resin could leak. Also, due to the stickiness of the adhesive, the sticky part is bound to catch dust and small debris. If the bottom becomes a dust and debris magnet, as is the surface upon which the epoxy will flow, then this reduces the aesthetics of the final surface.

Therefore, it is advisable to include a larger plastic sheet than the large void and ensure the plastic is well sealed in place. By so doing, you also are able to cover a wide area meaning that epoxy does not leak from the large void into other knots, cracks, or holes, which may be outside the scope of your current project.

Now, it could be argued that one can place a large plastic sheet over the entire project surface. However, this endeavor is risky as a little spill past the large void spreads across the whole bottom of the surface, creating a big mess. The best thickness of the plastic sheet to use when filling large voids in wood with epoxy is 6 mil (0.1524 millimeters), as this offers excellent durability.

Always wrap a fair bit away from the edges of the crack to avoid any weak pressure points. Any weakness or missing to cover a hole could lead to a huge mess to your woodworking project. Also, if you have chosen to use a low viscosity epoxy for your project, it is absolutely crucial to tape the bottom firmly. At this point, the care given to taping will define the outcome of the project.


Different dyes have different mixing solvents. For example, some may use water, alcohol, and more or a combination of several solvents. Also, some dyes do not involve the addition of a solvent for mixing and can diffuse directly into the epoxy resin.

The amount of dye needed depends on the scale of your project dictated by the number and size of the wood cracks. The desired color can be achieved by a single pigment or may involve the blending of two or three pigments.

Be sure to read all the manufacturer’s instructions for the use of the dye.


Mix the epoxy in a separate bowl from the dye. Often epoxy resin comes accompanied by hardeners, which include a mix ratio that should be strictly adhered to if optimal results are to be achieved.


Add the dye gradually in phases to the bowl of epoxy while stirring to ensure a homogenous mixture. The intensity of the desired color can be controlled by how much dye you add to the epoxy resin.


Pour the homogenous mixture in the wood crack from either side of the crack instead of the center to eliminate the susceptibility of the resulting surface to bubbles. Make sure the entire crack is filled with epoxy to the brim since you can sand excess epoxy, and this step serves to compensate for the high shrinkage factor in some epoxy resins. Check the manufacturer’s instructions for the curing time of the epoxy resin and have the patience to wait for complete curing.

A tip we often use is to simulate the homogenous mixture in a separate bowl that we can interfere with a spatula to assess the curing stage.


Instead of poring the first layer of epoxy and following it up with its subsequent layer later, then sand all the layers all at once, it is beneficial to sand in between layers because this exercise reveals some of the air pockets that can be filled as once continues to pour the epoxy.

You don’t want to wait for the curing time between layers and still find small cracks and holes just after sanding all the layers. In using colored epoxy resin to fill cracks in wood, it is crucial to hold your sander flat and level. If you start digging with one side of the sander in trying to get rid of the excess epoxy faster, it is highly likely you’ll end up in inconsistencies.


After sanding, then blow all the cracks to eliminate the sanding dust to avoid sand particles getting trapped in the colored epoxy that would significantly reduce the quality and aesthetics of the woodworking project. If available, use a vacuum blower that is far more efficient than regular blowers.

After this, then your second layer of epoxy should come right in. A trick to do here is to overfill the void just a hair high because the epoxy will sink a bit as it cures.

It is at this point that you want to employ your blow torch or heat gun or any such heat source to get the bubbles out since working with epoxy produces surface bubbles very often, and filling wood cracks with colored epoxy is a no exception activity.

Once the top layer is cured, it’s time to go back to the project with the sander to sand the epoxy layers off back down with the wood. No matter how careful you are, it is highly likely that you will end up with little holes. This phenomenon is due to the nature of crevices, some of whose faces face different directions and, as such, may contact the epoxies at different times, thus depriving the surface of some colored epoxy and leaving small holes.

To eliminate small holes quickly from the surface, one can use a cyanoacrylate glue such as Instant Bond Glue and Accelerator by Titebond. This technique should be repeated if desired results are not achieved, but the first time the glue enters the surface is often enough to fill cracks in wood. Do not forget to sand the glue again right off to ensure a clean surface for your woodworking surface.


Wood does not come in perfect appearance, and one is bound to land in wood with cracks. Filling wood cracks with colored epoxy is a worthwhile activity due to the improvement of wood in terms of aesthetics, function (strength), and utility. The steps to fill wood cracks with colored epoxy are easy and simple to follow while at the same time referring to specific product information to ensure the best results.

All the best in filling wood cracks with colored epoxy!