How to Fill Voids and Knot Holes in Wood
Occasionally, you will get a piece of gorgeous wood that has voids or knots in it. You wouldn’t want to add wood putty, because it wouldn’t retain the look of the knots. But, you want a smooth surface. The solution is to fill the wood knots and voids with epoxy. The results will be beautiful and you’ll be hard pressed to find the patch afterwards.
Materials:
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Instructions:
Begin by taping off the area around the holes, voids or knots. Press the edges of the painter’s tape down to seal it against the wood.
Remove the epoxy from the packaging. (I used Gorilla Glue Epoxy glue that sets up in 5 minutes.)
Snip or snap off the tip of the epoxy tubes.
Press the cap out of the plungers before trying to depress the plunger. Retain the cap to use if you have any leftover epoxy.
Depress the plungers and squeeze the two part epoxy into the packaging mixing tray. Stir the epoxy with the enclosed wooden stick until the glue is thoroughly mixed (should appear cloudy and all one color.)
Pour or spoon the epoxy into the voids, holes or knots. Do not let the epoxy touch your skin. Be sure to fill to the top or slightly over the top of the holes. Use disposable wipes to clean up any misplaced drips.
Allow the epoxy to harden and dry. Depending on the weather, the epoxy will likely need to dry and harden overnight.
When the epoxy has fully cured, remove the painter’s tape.
Sand the epoxy until it is smooth and level with the rest of the wood surface. Avoid the temptation to keep the sander on the epoxy too long or the glue will gum up the sandpaper. It’s better to use several passes and allow the epoxy to cool off between sanding.
Finish your wood with stain and/or topcoat of your choice. You can see my tutorial for refinishing reclaimed lumber for more details. You can read more on repairing holes in wood in “This Whole Post is on Repairing Holes.”
When you’re done it should be hard to locate the epoxy filled area! Can you spot it below?
Want more details about this wood table top and how to build the table?
I’ve seen something like this on worktops where in largish holes interesting objects e.g seashells have been added to the resin how would you go about doing this?
You might have more luck using resin than epoxy for that. I have a project where I used resin to encase butterfly wings: https://prettyhandygirl.com/dream-big-butterfly-window-resin-craft/
Hi Brittany – what grit sandpaper did you use?
220 grit sandpaper.
How would you recommend filling knots in prefinished hardwood flooring? epoxy?
Sure. That should work beautifully!
Can I add a little color to the epoxy so it’s darker when dry? I’m planning to stain my wood a dark color and I’m afraid since the epoxy is clear you will see the lighter wood thru the epoxy.
Bret, I think they sell a dye that you can add to it. I wish I had more information.
Thank You for that idea.
What grit sandpaper did you use for the epoxy after it dried
How would this work on floors? Will the epoxy hold up?
Robin, it should hold up perfectly. The epoxy is incredibly strong.
This is a great idea! I wonder if table top epoxy can be applied over .also the lumber in this project is long leaf pine a beautiful lumber, heavy , dense, hard as oak and can be past down generations.
Brittany,
How would you go about filling the knot hole if it goes completely through the wood?
Thank you!
Tape off the bottom of the hole.
Very, very good Solution…
Would this work on a vertical surface, like a door frame? I have a door that’s been scratched up by the previous owner’s big dog – but the scratches are too deep to sand smooth
Jyl, your surface must be flat and horizontal when working with the epoxy. For dog scratches, I’d use Bondo or strong wood putty instead. The epoxy is when you want to keep the knot hole or imperfect look.
thanks! I liked the idea of the epoxy because it’s clear and my door is just stained and I’m not sure I could get a really good match if I used bondo/stain (it’s an ancient door, with some kind of shellac on it) It’s probably time to just fill it in and paint it a wild colour! Thanks for your help!
I never knew this would work, so awesome! Thanks for this great tip!
You’re welcome.
Hi Brittany, Like Erin, I enjoyed this tutorial but want to know if I should stain first. What say you? 🙂 Thanks for the tip about sanding over the epoxy too! Wow, this table looks great! Thanks so much!!
~ Christina
You need to sand after adding the epoxy, which would ruin your stain. That’s why you want to stain after sanding.
This is awesome. I have an old table with a couple gouges that I’ve been wanting to refinish and this will be perfect!
One question, you say to stain after the epoxy. Is this true even if you want to use a dark stain, or would it make more sense to stain first in that case since the epoxy will be covering the wood?
Thank you!
You need to sand after adding the epoxy, which would ruin your stain. That’s why you want to stain after sanding.
Thank you again Brittany. I have little experience with staining so I appreciate the clarification.
Would it be beneficial to add (dark) stain to the portion that you put epoxy over, so that it matches?
This is a soon-to-be weekend project! Thanks for the tips!
Laura
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