Gaining confidence as a DIYer isn’t just about mastering the tools—it depends equally on using the right products. There’s a huge variety of options at the lumber yard or hardware store, and it's easy to get lost trying to figure out which is right for you. Join me in this series as I shop the Dunn Lumber aisles for a few of my favorite products and share some tips and tricks for using them.

Today, we’re taking a look at Epoxy Rot Fix—what it is, when to reach for it, and how to use it.

What is Epoxy Rot Fix?

So, you’ve discovered some rotten wood that needs repairing. Sometimes it’s easy to replace an entire board if it’s accessible, like a deck board or a stair tread. But for something like a rafter tail or windowsill, ripping out and replacing a single piece of wood is a much bigger ordeal. That’s where epoxy repair comes in.

Our friends at System Three make a full line of easy-to-use epoxy products designed to help treat and repair rot damage. 

The first product in the line is Rot Fix; it’s a liquid epoxy you’d apply after carving away all the loose rotten wood and exposing the semi-hard, structurally sound wood. This liquid epoxy is designed to soak into the pores of the wood and harden in preparation for the next step in the process, which is Sculpwood.

Sculpwood comes in a putty or paste form. The paste has a similar consistency to toothpaste and is best for filling in smaller cracks and voids, while the putty is thicker and better used to fill larger voids. Both the paste and the putty will hold screws and take paint when fully dry, just like real wood.

How to repair wood using SystemThree’s EndRot Kit

Step 1: Apply Rot Fix

Follow the instructions to combine the two-part epoxy system included in the kit. Then, use an inexpensive paint brush to apply the mixture to the wood, taking care to get the product into all the cracks and crevices. Let the epoxy harden and dry according to the instructions included in the kit.

Step 2: Apply Sculpwood Paste

To use the paste, dispense equal parts (eyeballing it is fine here) from each of the tubes of epoxy included in the kit onto a piece of cardboard, and mix together using a stir stick. Continue mixing the products together until the paste becomes consistent in color with no streaking.

Apply the paste to the smaller cracks in the wood using the stir stick. Push the paste into the crack to completely fill the void. Use the edge of the stir stick to smooth out the paste on the surface of the wood.

Step 2: Apply Sculpwood Putty

Using gloves, scoop out equal parts of the two-part epoxy putty and knead them together until the putty is consistent in color with no streaking. The resulting mixture will be thick and stiff but easy to shape and tool as you pack it into the wood's cavity. 

Using gloved hands or a putty knife, apply some of the mixture to the wood and force it into the voids, overfilling a bit (you’ll be able to sand it down later). Let the putty dry completely, according to the package instructions, before sanding.

Once dry, your repaired board can hold screws and take paint, just like real wood. 

For more DIY tips and tricks, check out the videos in our Tools 101 series through our DIY Tool Guide: What Tools To Buy and How To Use Them.