How to Repair a Broken Windowsill

Introduction

If your windowsill (otherwise known as the windowsill stool) is broken, chipped, or scratched, follow this guide to repair the damaged wood.

The windowsill is a decorative piece of trim installed beneath the window. The windowsill is located inside of the house and is meant to accentuate the window.

Before using this guide, inspect the windowsill for any termite damage, mold, or fungus. Damage caused by pests or mold fall outside of the scope of this repair.

Ensure that children and pets are a safe distance from the repair in process. The wood filler should not be ingested at any time.

What you need

Step 1 How to Repair a Broken Windowsill

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Remove any loose, splintered, or jagged wood by hand.

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Step 2

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Grab three straight sections of cardboard.
Apply Vaseline to one side of each section of cardboard by hand. Vaseline will prevent the wood filler from sticking to the cardboard.

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Step 3

Hold one section of cardboard underneath the corner needing repair with the Vaseline side facing up.

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Step 4

Apply wood filler to the corner by squeezing the tube.

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Step 5

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Position the other two sections of cardboard on either side of the corner to help shape the filler into a right angle. Place the sides with the Vaseline on them toward the filler.
Use a putty knife or plastic butter knife to smooth filler if needed.

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Step 6

Remove the cardboard sections before the filler dries completely.
Allow the filler to dry for approximately six hours. The filler may take less time to dry if repairing a smaller section of the apron. For dime sized reparations, the filler will take approximately two hours to dry.

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