Asked on Mar 04, 2015

What to fill a broken knot in hardwood flooring with?

by Jeremy
I recently had a chunk of a knot in our tavern/cabin grade hardwood bust out. What is a good product or what can I do to fill it back in that will look ok or actually work. I am afraid my little girls will stub a toe or get a splinter from the hole. Any help out there?
  12 answers
  • Darla Darla on Mar 04, 2015
    If it is larger than 1/2 inch, I would recommend that you whittle a piece of wood to fit loosely and glue it in, fill the gaps with plastic wood, and sand it even. If smaller than that, you can just use plastic wood. It dries very hard so it's easier to sand if it's not completely cured.
  • Maryellen Maryellen on Mar 04, 2015
    You can "make" sawdust - the finer the better - out of wood that matches your flooring, then mix it to a paste consistency with some polyurethane (same sheen as the existing floor), and press it into the hole with a putty knife. As mentioned before, don't over fill. The advantage to using this method is that it will dry to the same level as you fill it with no shrinkage. DO NOT use gorilla glue or any other glue that needs water to cure as it will expand!
    • Jeremy Jeremy on Mar 04, 2015
      @Maryellen It is not a very big hole or divot. it is kinda shaped like a heart but pointed. Afraid the girls will get splinter from center point or catch it on socks and make it worse. About the size of a dime, shaped like pointy heart and about a 1/4 inch deep at deepest. Could I just fill with polyurethane liquid and let dry. Dark knot and I would really like to just do clear so we can still see it. Thoughts?
  • EdiLeck EdiLeck on Mar 04, 2015
    Do you still have the piece came out of the hole? I would glue it back in place and fill in any gaps with 'sawdust putty!'
  • Maryellen Maryellen on Mar 04, 2015
    Jeremy Sure! It will take a bit of time to dry, but if you like the look of the hole, go for it! I think I'd layer it in and not fill it up all at once, though. I have lots of tiny knot holes in part of my floor, where we had to have flooring laid to match the other half of the room when we took down a wall. The new stuff just isn't as tight as the older flooring. I've partially filled lots of them with poly. I did tint it a bit with some stain, as the "holes" were dark and the wood itself is white oak that was not stained. I mixed it in an old nail polish bottle and just use the brush to drip it into the holes. Even if you don't fill yours all the way to the top, you'll be able to paint some on the edges to take some of the sharpness down. It will also keep dirt from filling the hole and you'll be able to clean it much easier. And down the road, if you get cracks that open up, you can treat them the same way. Good luck!
  • Ray Phillips Ray Phillips on Mar 05, 2015
    As a retired builder I have filled knot holes with anything from wood putty to mixing sawdust with glue to just water based poly. if you use poly you will have to put a little at a time and let it dry before you add more. Water based dries in minutes and you can add more and best of all no oder. Hope this helps.
  • Pauliegirl1 Pauliegirl1 on Mar 05, 2015
    I am with EdiLeck....but any of these would work !!
  • Pete Wells Pete Wells on Mar 05, 2015
    Wood putties will only work where there is no traffic, I'm in agreement w/EdiLeck
  • Michele Curlee Michele Curlee on Mar 05, 2015
    If you're into something unpredictable and it's in a spot you want to highlight, you could find a stone or object of the right size and set it in place with self-leveling epoxy! That would be so cool, now that I thought of it, I'm trying to think of a place I could use the technique!
  • April E April E on Mar 05, 2015
    I would use clear resin and just fill the hole the resin will bind to your wold and would "hide" the missing peice
  • D & K D & K on Mar 05, 2015
    Use a two part epoxy to glue the piece back into place and fill any gaps with the same epoxy. Fill any remaining holes or gaps using a putty knife and wipe the surface with a cloth and a little lacquer thinner to remove any excess but don't saturate the area. You don't want to soften or remove any of the existing finish. Be sure to use a near clear/amber colored epoxy and not the type that looks grey or metallic. The clear/amber color will resemble the appearance of the surrounding wood and won't look as noticeable.
  • Christine Agostini Christine Agostini on Mar 06, 2015
    There is a product called Stainable Wood Filler. You can find it at most home improvement stores near the stains and wood fillers/putties. It's simply wood filler mixed with fine grade sawdust capable of absorbing any stain needed to match the surrounding wood. Also, cork material can be cut to size and shape and will pick up stain color if you're working with a very rustic type of flooring.
  • Kentuckylady Kentuckylady on Mar 14, 2015
    Hi, I don't have an answer for you, but I bet TIM CARTER THE BUILDER could....check out his website and ask him......