How to Fill Cracks in Wood With Epoxy

  • More than 20 Years Woodworking Experience
  • 7 Woodworking Books Available on Amazon
  • Over 1 Million Words Published About Woodworking
  • Bachelor of Arts Degree from Arizona State University
Join the Facebook Group Here!

I receive Commissions for Purchases Made Through the Links in This Post.

This is How to Fill Cracks in Wood With Epoxy. In this post I’ll show you how to use two part epoxy to fill cracks in wood.

If You Like My Posts, You'll Love My Books

See My Woodworking Books Here

Filling Cracks in Wood With Epoxy

How-to-Fill-Cracks-in-Wood-With-EpoxyTwo part epoxy is often overlooked when it comes to filling cracks in wood. This is typically a job that’s reserved for wood putty, or wood filler. In reality, epoxy can actually be superior in many ways.

For starters, epoxy is in adhesive. This means not only will it fill the gaps in your project, it will also bond to the insides of those cracks, which helps hold the pieces together. This is also a much stronger bond than most paste fillers.

Also, you can color epoxy with different pigments to match nearly any color of wood that you need to. This means you can create a perfectly custom filler product with the exact color you need, right on demand.

Finally, many times it’s easier to fill with epoxy simply for the fact that it flows better. It’s a much easier time getting the product down into the crack, and the deeper you can create your fill, the more thorough and strong that filled crack will actually be.

See Also: Wood Filler Inlay Step by Step

Free Woodworking Tips Every Monday

Add Me to the List!

Select the Best Epoxy

Filling cracks with epoxy starts out with using the very best epoxy. No matter what you do, the strength of the fill is really going to come down to the strength of your epoxy.

Don’t waste your time with bottom shelf epoxy products that are super inexpensive, or that are sold at bargain stores. Most of the time, these are older formulations, or they are just not a very good product.

By the same token, you also don’t need the very high-end epoxy products that are meant for creating surface layers and clear casting. These products are way more than you actually need, so it’s best to shoot for somewhere right in the middle.

Pick out a nice, name brand epoxy from the brand that you recognize, and you won’t have to worry about your filler product failing you. It’s just one less thing to worry about when it comes to your project, and you’ll be happy to work with a better product in the long run.

See Also: How to Choose the Best Epoxy Resin for Wood

Choose the Open Time You Need

Another big difference that you need to think about is the amount of open time that your epoxy will allow you. Open time is the amount of time that you’re able to work with the product while it remains in the liquid state.

After the product passes through the amount of open time it will become a gel, and no lnoger flow where you need it to. For most of your epoxy products, you’ll have a choice between five minutes and 60 minutes of open time.

Most cases, if you don’t have cracks that are gigantic, the five minute variety will work perfectly. However, if you plan on tinting the epoxy to a different color, you may need more time to work with the mixture before it starts to solidify.

Free Woodworking Tips Every Monday

Add Me to the List!

Though you don’t actually need 60 minutes to get the product into the crack, you do need more than five minutes in order to get the color match correct. Don’t worry, no matter which epoxy you purchase, it typically takes 24 hours for a full cure either way.

You can look at it this way, the five-minute epoxy really isn’t saving you any more time than using the 60 minute type.

See Also: 50 Awesome Reasons to be a Woodworker

Tint the Epoxy if Needed

One of the awesome things about using epoxy for your filler it is that you can tint it using different types of pigment. This is basically a powder, or a powder suspended in a liquid that you mix to create a certain color.

If you really want to make your cracks disappear, I definitely recommend tinting your epoxy to match the surrounding wood. This is also a trick that you can do when you were doing inlay work, and you can tint the epoxy to match the background color.

When you are doing inlay work, the tinting helps hide any little gaps or differences between your inlay pieces and the surrounding wood. When you fill cracks, you can make them disappear, and look like a natural part of the wood.

If You Like My Posts, You'll Love My Books

See My Woodworking Books Here

See Also: 15 Helpful Tips for Doing Epoxy Inlay in Wood

Tips for Mixing Two Part Epoxy Filler

There are some tips for mixing your two-part epoxy that will help you do a better job right from the beginning:

  • Make sure to dispense even amounts of both the hardener and the resin, unless you are directed to do otherwise, most products are a 50-50 mix.
  • Resist the temptation to lose too much of the hardener, because even though it may help your filler set up a little faster, it will also cause it to be more brittle.
  • Use a small towel or some toothpicks to mix the product thoroughly, making sure that you scrape off the toothpick as well as the edges of your container as you mix.
  • Don’t be afraid to spend about a minute mixing the product so that way you know you have a thorough, and complete blend of the two chemicals.

See Also: 9 Massive Tips for Using Wood Dye to Color Your Projects

Filling Cracks in Wood

The easiest method for filling your cracks with this custom two part epoxy mixture is to simply transfer it from your container into the crack. However, there are a couple things you can do to make the process easier.

First, take a look at the bottom of the piece of wood with the crack. If the crack goes all the way through, you need to put some sort of a dam in place in order to prevent the epoxy from simply running out the other side.

In a case like this, one of the best things that you can do is just apply a piece of masking tape to the bottom of the crack. Press it firmly against the wood on both sides, and it will create a perfect seal and hold your epoxy where you want it to go.

After that, it’s all about filling the gap as deeply and as evenly as possible, slightly over filling the top so you can sand it back later. The last thing you want is to fill it to shallow, so always go a little too much.

Give the product a full 24 hours to cure, or whatever time is recommended by the manufacturer of the epoxy that you use. Don’t skip this part, because the epoxy will not sand until it’s fully cured.

Free Woodworking Tips Every Monday

Add Me to the List!

See Also: The Best Wood Crack Filler

Sanding the Fills Level

Once your fill has cured, the next thing you need to do is sand it level to the rest of the wood. The easiest way to do this is with a sanding block and sandpaper.

The sanding block is your best friend because it will automatically target the high spots, which is exactly what you need to bring the epoxy down level to the rest of the surface. Simply wrap your block with paper, and start sanding.

Check your sandpaper often, because sometimes epoxy can get wadded up in between the grains on your paper, and can cause it to become clogged. When that happens, your sandpaper becomes less effective, so you definitely want to avoid that.

Keep on sending it until the crack becomes completely level with the rest of the piece, and then start sanding a wider area to blend everything together. If everything works out, you’ll have an almost invisible crack when you’re done.

See Also: 10 Step Guide to Wood Finishing

Finishing the Surface

After all of this prep work, you’ll probably end up in a spot where you are ready to finish your project. Rest assured, the epoxy is not going to alter the way you finish your piece in most cases.

Oils are not going to absorb the same way in epoxy as bare wood, and in fact they won’t absorb at all. However, for most film finishes the coat will adhere just the same as if it were directly on wood.

It’s my recommendation that you choose a film and finish like a lacquer in the majority of cases where you use epoxy as your wood filler product. Test some oils if you like, but no there will be a slight difference in that area.

See Also: 23 Common Wood Finishing Mistakes for Beginners

Your Action Assignment

Now that you know all about using two-part epoxy to fill cracks in your woodworking projects it’s time to get out into the shop and take action.

One of the best things you can do with this new technique is practice a little bit before you actually have to use it for real. This helps you train yourself in an environment without any consequences, and it can be quite a stress reliever.

If You Like My Posts, You'll Love My Books

See My Woodworking Books Here

Get yourself through a few different fills, and even practice tinting the epoxy a little bit with some pigment to see how it affects the color. You’ll be happy that you got the experience, and your fills will look amazing.

If you have any questions about filling cracks with epoxy, please post a question and I’ll be happy to answer them. Happy building.

Post Author-

  • More than 20 Years Woodworking Experience
  • 7 Woodworking Books Available on Amazon
  • Over 1 Million Words Published About Woodworking
  • Bachelor of Arts Degree from Arizona State University
Buy My Books on Amazon

I receive Commissions for Purchases Made Through the Links in This Post. Join My Woodworking Facebook Group


You Can Find My Books on Amazon!

woodworking and guitar making books

An Exclusive Member of Mediavine Home

Westfarthing Woodworks LLC is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.