How to Remove Silicone Window Caulking

Silicone caulk works as a glue and a sealant, filling gaps and providing an excellent waterproof barrier. Typically used in bathrooms where water leaks are a concern, it also can be used as a sealant around windows. This can lead to problems with exterior maintenance and painting. Because nothing will stick to it, including more silicone caulk, it cannot be painted, stained or reapplied. To top it off, cured silicone is extremely difficult to remove. While there are solvents on the market that dissolve silicone, they are notoriously ineffective, harsh and sometimes dangerous. Old-fashioned elbow grease is the best method for removal.

Things You'll Need

• Single-edged razor blade
• Medium-duty leather gloves
• Pliers
• Sand paper
• Small brush

Instructions

1. Wear gloves to protect your hands, as you will be working with sharp and tough objects.

2. Scrape off the old caulking with a razor blade held at a very low angle, taking care not to gouge the window frame with the blade. Once the old caulking is cut, it may be possible to pull off an entire strip of caulking by grabbing it with pliers or by hand. The thicker the bead, the easier it is to remove.

3. Once the bulk of the caulking is scraped away, the residue can be removed with sandpaper. Use a small brush to clean up any dirt or particles left on the window, frame or sill.

4. If you plan to paint, instead of sanding you can use a "siliconized" acrylic latex caulk (which can be painted and will stick to silicone) as a bridge between the paint and the silicone. Note that regular acrylic caulking will not adhere properly to cured silicone, so check the label.

5. Apply new caulking according to the manufacturer's specifications.

Tips & Warnings

• Paint strippers and other solvents that are sometimes used to remove silicone can weaken the seal on insulated glass. Use with caution.

References

• The Natural Handyman
• Ask the Builder