If your windows have old paint splatters on them, you likely want them gone. Paint on windows is unsightly and diminishes the appearance of the windows. It may be impossible to determine whether the paint on the windows is water-based or oil-based paint, especially if you were not the one who put it there. It is best to start with the least toxic method for removing old paint from windows. Water-soluble paint will come off much easier than oil-based paint and will require more mild removal products.
Fill an empty spray bottle with hot water. Add 1 tbsp liquid dish soap to the bottle and shake it up to combine the ingredients.
Apply a generous amount of the spray to the paint on the windows. Allow it to sit on the window for about five minutes.
Use a plastic scraper to peel the paint from the windows. If the paint does not come off with the plastic scraper, use a razor blade held at a 30 to 45 degree angle to gently pry the paint from the glass. Use caution so as not to scratch the glass.
Use vinegar if the soapy water did not remove the paint. Heat 1 cup white vinegar in a pot on the stove over medium heat. Leave the vinegar on the flame for about five minutes, or until it is hot. Use a funnel to transfer the vinegar to an empty spray bottle. Saturate the paint spots with the vinegar. Scrape off the paint with the razor blade or plastic scraper.
Fill a small container with acetone. You can buy acetone at most home improvement or hardware stores.
Dip a cotton ball into the bowl of acetone. Dab the acetone onto the paint using the cotton ball.
Allow the acetone to sit on the glass for about five minutes. Hold a razor blade at a 30 to 45 degree angle and gently scrape the paint off of the windows. Apply more acetone as needed until all of the paint is gone.
Use white spirit in the same manner if the acetone did not remove all of the paint. Repeat the process, if necessary, until all of the paint has been removed.
Mix equal parts isopropyl alcohol and turpentine into a small container. Stir the ingredients with a spoon to combine.
Dip a cotton ball into the ball to absorb a generous amount of the solution. Sponge the solution onto the paint spots.
Use a razor blade held at a 30 to 45 degree angle to gently scrape the old paint from the glass. Add more of the alcohol and turpentine solution, if necessary, until all of the paint has been removed.
Rub a stick of chalk over the affected area. This will remove any last traces of the paint and help to polish that area of the window glass. Press gently when rubbing the chalk so as not to damage the window glass.
Clean the windows thoroughly after using any of the above methods for removing paint. Use equal parts white vinegar and water mixed in a spray bottle. Spraythe windows with the solution and wipe them clean with balled-up newspaper. Clean the windows with the vinegar solution after using one removal product and switching to another. This will help you to see exactly how much paint is still left on the windows. If using a razor blade, make sure the blade is sharp. A dull blade will cause scratches on the windows. When using the razor blade or scraper, run the blade in only one direction rather than back and forth. This will reduce the chances of scratching the glass.
Work in a well-ventilated area and wear rubber gloves when working with acetone, white spirit or turpentine. These products are flammable; keep away from extreme heat or fire. Dispose of products such as turpentine, white spirit and acetone properly. These solvents should not be poured down the drain. Take the products to a recycle centre in your area that disposes of such products, or put the liquid in a sealed can and dispose of it in your trash.