How to properly FILL CRACKS around Window Sills, by Gosforth Handyman on YouTube. 15 min 29 s.
- Video length
- 15 min 29 s
- Time to do it
- 30 minutes
- Difficulty
- Easy
- Steps
- 10
What you need
Steps
Clear the gap with a scraper and a utility knife. Remove loose plaster, old caulk and flaking paint so the new caulk can bond to a clean surface.
Wipe out the dust with a damp cloth and let the area dry completely. Caulk will not stick to a dusty or wet surface.
Check the depth of the gap. If it is deeper than about 6 mm, push in a foam backing rod so the caulk has a base and does not sink.
Run masking tape along both edges of the gap if you want a neat line. Press it down firmly so caulk cannot creep under it.
Fit the caulk tube into a caulking gun and cut the nozzle at a 45 degree angle. Make the opening about the width of the gap.
Push the bead into the gap at a steady pace, keeping the nozzle in contact with the surface. Do not stretch the caulk thin.
Smooth the bead with a damp finger or a caulk smoothing tool. Wipe the tool clean after each pass.
Peel off the masking tape while the caulk is still wet. Pull it away at a low angle so the edge stays sharp.
Let the caulk cure for the time on the tube. If it shrinks, apply a second thin bead and smooth it again.
Paint over the dried caulk with the wall or trim paint. Use a brush and keep a wet edge for a smooth finish.
Tips and common mistakes
Use a paintable acrylic caulk, not silicone, if you plan to paint over the joint.
Do not fill a wide gap in one thick pass. Two thin beads dry better and shrink less.
Keep a damp cloth handy and clean excess caulk before it skins over.
Wear eye protection and cut away from your body when trimming old filler with a knife.
Questions
What kind of caulk should I use around window sills?
Use a flexible paintable acrylic caulk for gaps that need painting. Avoid silicone unless the joint will stay unpainted, as paint will not stick to it.
Can I paint over the caulk?
Yes, once it is fully dry. Check the tube for the recoat time, then apply your normal wall or trim paint.
How long does the repair take?
Most caulks skin over in 20 to 30 minutes and can be painted after a few hours. Deep gaps may need a second bead the next day.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
