Knothole Repair

Home repair expert Henry Harrison teaches a homeowner how to fix her softwood floor where several of the knots have fallen out, leaving behind holes.

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Filed under: Flooring, Repair, Wood, How To

Since putty would stand out noticeably, they cut a knot from another piece of wood and use it as a patch. On his elbow grease scale of one to four, Harrison gives this job a two.

Materials and Tools:

portable workbench
belt sander
jigsaw
tape
spring clamps
hot glue gun
hot glue sticks
file
putty knife
pencil
sandpaper
safety glasses
dust mask
rubber gloves
utility knife
spatula
cotton swab
1/8-inch plywood
wire
salvaged pine
contact cement
paper
putty
stain

Steps:

1. Transfer the imprint of the shape of the hole onto a piece of paper by rubbing your finger around it until you can see the outline, then enhance the imprint with a pencil. Imprint both the inside and the outside of the hole if possible.

2. Choose a matching knot from the salvaged lumber.

3. Apply contact cement to the paper template and let it dry until tacky. Stick template over knot and set aside to dry.

4. Cut off a section of plywood that is a little larger than the hole. Score it down the center so it can be bent. Take a piece of wire and poke it through the bend.

5. Put hot glue around the edges of the plywood piece. Fold the wood and slip it through the hole, then use the wire to pull up and stick the plywood to the underside of the floor. Hold the piece in place for a minute until the glue dries and then push the wire through the hole.

6. Clamp the salvage wood to the table, making sure that the knot with the paper template stuck to it is clear of the table.

7. Cut away some of the excess paper with a utility knife.

8. Using a jigsaw, cut along the outside of the template line without touching it.

9. Fine-tune the edges of the patch with a file to fit the hole perfectly.

10. Mix up the high-grade adhesive and wood putty combination and spread it around the edges of the hole. Insert the knot, making sure that the putty is spread evenly. Allow 30-minutes to dry.

11. Peel off the paper template. Mask off wood floor area around the patch with tape to protect it while you sand the replacement knot flush with the floor.

12. Use heavy grit sandpaper on a belt sander to sand the patch flush. Knots are the hardest parts of the wood so it will take a little extra elbow grease.

13. After the knot is close to being flush, switch to fine grit sandpaper then finish sanding by hand.

14. Remove tape and any remaining debris.

15. Using a cotton swab, apply a liberal amount of stain to the knot and pay close attention to letting it soak into the white edges well. Once it has soaked in, wipe up the excess with a towel. Allow the stain to dry.