What Is And How To Use The Epoxy Wood Filler 

Epoxy wood filler is a moisture-resistant adhesive that bonds with wood instead of sitting on top of it like regular water or oil-based filler.  It’s a top choice for filling in large gouges or cracks and rebuilding rotten wood.

What is an Epoxy Wood Filler, and What Do I Use it For?

Epoxy Wood Filler

Epoxy wood fillers come in two parts that you mix before application. While most wood filler epoxies come in a putty-like compound, you can also purchase liquid epoxy to harden wood and fill small cracks. You can use epoxy filler on interior and exterior projects.

Dry time varies, but most wood epoxies are ready to be sanded, painted, or stained within a few hours. If you don’t want to paint or stain, you can find a product that dries a similar color to your wood.

Use epoxy wood filler for:

  • Any wood that needs moisture resistance
  • Window sills, fence posts, deck boards, porch columns
  • Furniture repairs
  • To fill in large holes
  • To rebuild or strengthen wood rot

For minor furniture cracks and nail holes, consider regular wood filler.

How to Use Epoxy Wood Filler

Using best epoxy wood filler is a straightforward process. Before you get started, wear a pair of latex or nitrile gloves and appropriate safety gear.

Step 1: Prepare the Wood

Scrape away damaged or severely rotten wood using a chisel or putty knife. 

Step 2: Apply an Epoxy Consolidant (For Wood Rot Only)

If you’re repairing an area with wood rot, apply a wood consolidant first. An epoxy wood consolidant is a liquid epoxy that can soak into the wood, hardening the damaged areas.

These products come in two parts, often labeled “part A” and “part B.” Follow the directions to mix and apply the product to your wood with a paintbrush, squirt bottle, or by pouring it onto the damaged area. 

Most liquid wood epoxies dry within four hours but refer to the directions on the package.

Step 3: Mix Your Epoxy Wood Filler

Epoxy wood fillers will come with two packages of putty compound marked “A” and “B” or one package of putty and a cream hardener. Follow the directions to mix the filler. 

Most often, mixing entails hand-kneading the putty. (Wear gloves and a long sleeve shirt.)

Step 4: Spread and Allow to Dry

Press the putty into the hole or crack you’re filling until you’ve reached the desired shape. Then, allow the wood filler epoxy to dry. 

Dry time for most products is about an hour.

Step 5: Sand and Paint if You’d Like

With the wood epoxy dry, you can sand it until you’ve reached the desired shape and smoothness. If you wish to paint your wood epoxy, you can do so now.

Tips for Using Epoxy Wood Filler

Tips for Using Epoxy Wood Filler

If you’re new to DIY projects using a wood epoxy resin filler, here are some helpful tips to get you started

  1.  If you like, you can mix epoxy with tints and pigments from an art supply house for an additional touch of color.
    • When applying, make sure you’re doing so carefully with a knife or wooden stick, as it can be difficult to clean up.
  2. Follow the manufacturer’s recommendations when mixing your epoxy, and make sure you’re using the right ratios to ensure that the product cures.
  3. Epoxy generates heat from the chemical reaction as it cures. It’s best to mix it in smaller batches.
  4. Take the necessary safety precautions when working with epoxy in household repairs. It’s important that you’ve got proper protective clothing and safety glasses.
    • Work in a well-ventilated space.
  5. When mixing, try and do so in a plastic container, as epoxy simply peels out after it has set.
  6. Epoxy is not UV-resistant, so if it’s meant for the outdoors, add a topcoat to your wooden piece with an exterior varnish or paint.

Frequently Asked Questions (FAQ)FAQ

Will epoxy stick to wood filler?

It depends on what type of epoxy wood filler you’ve purchased. Generally speaking however, epoxy wood fillers are a reliable adhesive so they will stick. Epoxy resin in particular sticks to nearly all surfaces and the thinner the resin, the more likely it’ll penetrate the pores of the wood and bind to it.

What is epoxy filler used for?

They’re great if you’re looking for a filler that has more structural integrity – perhaps for a widening crack or a rotting void. They come in either a tube or a can and can be either clear or colored – depending on your needs. When using an epoxy filler, it’s important that you apply it with care. 

How Do You Fill Holes in Wood with Epoxy?

There are a couple of steps that you’d need to take to fill holes in the wood with epoxy. 

1. If you’re filling rotting wood, you’d need to find and stop the cause of the rot. If you’re not sure what’s causing the rot or how to repair it, it’s best to call a professional for some help. If there’s moisture within the rot, ensure that your wood has about a week to dry properly as trapped moisture can cause additional rot and even prevent the epoxy from bonding properly.
2. Then, you’d want to probe the area surrounding the damaged woo to determine the extent of the rot. Soft wood should either be removed or reinforced with epoxy consolidant.
3. Once you’ve determined the cause, proceed to remove all decayed wood before applying the liquid wood epoxy consolidant according to the manufacturer’s instructions. You’ll want to work it into the wood with a small brush until the entire wood is saturated. Then, go ahead and let it dry for at least a week before starting the next step.
4. Before applying the epoxy, you’d need to go ahead and mix it. As epoxy can harden – especially in warmer weather, you’d want to work with it quickly. Try and keep your epoxy materials as cool as possible when you’re working with it, and you can speed up hardening with a hairdryer or spotlight.
5. Then, go ahead and fill the wood cavity with the epoxy wood filler. Start by pressing the putty into the area with a putty knife. Make sure that you’re pressing hard so all voids are filled and there’s a good bond.
6. After that, you’ll want to make sure that you’re wearing chemical-resistant rubber gloves to shape the epoxy with your fingers and overfill the repair. You don’t need to get the shape perfect, just make sure that you’ve got enough material leftover to match the surrounding profiles.
7. With that, you’re good to go when it comes to filling the hole with epoxy. If it’s warm, you’ll be able to shape it in about three to four hours. If not, you’ll need the patch to harden overnight. Once that’s done, you can go ahead and sand the epoxy or proceed to paint over it.

Is epoxy a good wood filler?

Epoxy wood filler is ideal for restoring old wood that is too hard to remove or expensive to replace. It can take care of filling holes and cracks completely. You can shape epoxy putty to fit spaces.

It sticks really well and it makes a durable surface. You can also sand it.

When should I use epoxy wood filler?

Use an epoxy wood filler to fix cracks and holes and for replacing wood that has been damaged. You can also fill and replace rotted wood with an epoxy filler because it creates a permanent bond.

Depending on the type of epoxy filler, you can put it on with a brush, a palette knife, a plastic knife or even a syringe.

Can you paint over wood filler?

Once epoxy wood filler attaches to the wood and cures, you can paint it. But, wood is porous and this type of wood filler is not, so you might need to do some more prep to the surface.

Do you have to seal wood before epoxy?

It is very important to seal a porous surface like wood before using epoxy filler. The easy part is that you can apply some resin to the wood and let it set as a sealer.

How do you fix rotten wood without replacing it?

Use wood epoxy resin filler to fill in areas of rotted wood. They are simple to apply and they stop the rotting process, cure quickly and don’t shrink.

Is wood filler waterproof?

Wood filler contains sawdust or wood fibers mixed with some type of binder. This means it isn’t weatherproof, but it is water-resistant after it is fully dry. Wood putty typically contains with epoxy, fiberglass or polyurethane, and it doesn’t fully harden. You can use it for outdoor projects.