How to Remove Acrylic Caulk from a Window

When replacing or weatherproofing old windows, you will need to first remove the old acrylic caulk from the windows. Follow these instructions for removing acrylic caulk from a window.

Step 1 - Prepare the Area

Prepare to get to work by wearing gloves if the knife you will be working with is sharp, and to protect you from blisters if you have many windows to uncaulk. With a caulk softener or remover, less elbow grease will be required, but blisters may form if you are doing a lot of work without wearing protective gloves. Brush off the dirt and dust from the window sill and old caulk with a thick-bristled paintbrush.

Step 2 - Apply Caulk Remover

Although you can scrape off caulk without using a remover, this chemical product will make your job much easier. If you are against using chemicals, dampen the caulk with water and/or rubbing alcohol before scraping. If you prefer using the chemical remover, apply an all-purpose caulk softener or remover to the caulk that you want to remove. Allow to sit for at least 2 hours or the length that the instructions recommend. Test after the allotted time; if the caulk doesn't remove somewhat easily, leave for another half hour or so.

Step 3 - Remove Caulk with Knife

Now the work begins, although the caulk softener will have made the effort more minimal. Push the putty knife under the caulk and scrape off. Different sizes of putty knifes are helpful, allowing you to more easily remove small pieces that may be wedged in corners.

Step 4 - Remove Caulk from Windows

To remove old caulk that may have gotten on the windows, soften the caulk with a damp sponge. Using a razor blade, scrape towards the window edge. Hold the razor blade as level with the window as possible and scrape the caulk off from where it meets the window. Dampen the caulk often as you scrape in short, even strokes.  Any remaining residue from the caulk on the windows can be wiped off with a cotton ball soaked in rubbing alcohol

Step 5 - Clean off the Area

After all the caulk has been scraped off, wipe down with a dampened sponge to remove crumbs of caulk and and caulk softener that may be on or around the windows. Now that the area is clean and free of caulk, dry everything down with a dry cloth. Finally, brush off any remaining bits of dry caulk residue from the window sill and edges with a thick-bristled brush.