Skip to main content

Free Shipping on Domestic Orders $75+

How to Repair a Broken Windowsill

What you need

  1. How to Repair a Broken Windowsill, How to Repair a Broken Windowsill: step 1, image 1 of 3 How to Repair a Broken Windowsill, How to Repair a Broken Windowsill: step 1, image 2 of 3 How to Repair a Broken Windowsill, How to Repair a Broken Windowsill: step 1, image 3 of 3
    • Remove any loose, splintered, or jagged wood by hand.

    Ask FixBot

    Add Comment

  2. How to Repair a Broken Windowsill: step 2, image 1 of 3 How to Repair a Broken Windowsill: step 2, image 2 of 3 How to Repair a Broken Windowsill: step 2, image 3 of 3
    • 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.

    Ask FixBot

    Add Comment

  3. How to Repair a Broken Windowsill: step 3, image 1 of 1
    • Hold one section of cardboard underneath the corner needing repair with the Vaseline side facing up.

    Ask FixBot

    Add Comment

  4. How to Repair a Broken Windowsill: step 4, image 1 of 2 How to Repair a Broken Windowsill: step 4, image 2 of 2
    • Apply wood filler to the corner by squeezing the tube.

    Ask FixBot

    Add Comment

  5. How to Repair a Broken Windowsill: step 5, image 1 of 3 How to Repair a Broken Windowsill: step 5, image 2 of 3 How to Repair a Broken Windowsill: step 5, image 3 of 3
    • 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.

    Ask FixBot

    Add Comment

  6. How to Repair a Broken Windowsill: step 6, image 1 of 1
    • 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.

    Ask FixBot

    Add Comment

  7. How to Repair a Broken Windowsill: step 7, image 1 of 2 How to Repair a Broken Windowsill: step 7, image 2 of 2
    • Sand the filler with 120 grit sandpaper until it is satisfactory.

    • Repeat steps 4-7 if the corner is not the desired shape.

    Ask FixBot

    Add Comment

  8. How to Repair a Broken Windowsill: step 8, image 1 of 2 How to Repair a Broken Windowsill: step 8, image 2 of 2
    • Paint the finished corner with the desired shade of paint.

    • Allow the paint 3 hours to completely dry.

    Ask FixBot

    Add Comment

Conclusion

Once the paint dries, the project is complete.

Cancel: I did not complete this guide.

Julia Byrd

Member since: 03/03/21

157 Reputation

1 Guide authored

0 Guide Comments

Add Comment

View Statistics:

Past 24 Hours: 4

Past 7 Days: 46

Past 30 Days: 161

All Time: 8,943