If you have old windows and the glass has become etched, this can be due to exposure to weather, dirt, or simply pollution. If you have etched glass, your glass will have buildup on the glass surface or the glass may look discolored. Fortunately, there are some ways you can clear up your windows on your own so they look new again.
Use Vinegar and Water
One of the easiest solutions to make to clear up your etched glass is vinegar and water. Simply fill up a spray bottle with half water and half white distilled vinegar. Before you get started, wipe over the window to remove any dirt. This will allow you to see exactly where the etching is on the window. Spray the vinegar solution on the stained areas, and then use a fine grade steel wool pad to gently wipe over the surface.
You need to be careful that you do not apply hard pressure while doing this. You will have to wet the glass down as you go, as you do not want to rub the wool pad over a dry window or you could cause more damage. When you are finished, use a squeegee to dry the window.
You may need to do this a few times to get the window completely clean. When you are finished, spray the window down with clean water to remove any residue left over and use the squeegee to dry the windows.
Use Ammonia and Isopropyl Alcohol
Fill a spray bottle with three parts ammonia, alcohol, and isopropyl alcohol. Spray the mixture on the etched areas of the window glass, and then wipe over the glass with a microfiber cloth. A microfiber cloth works best, as it will not leave behind any lint. You will have to scrub to get the tough areas clean.
You may have to repeat this process a few times to completely get rid of the stain. When you are finished, fill a spray bottle with clear water and spray over the window again to rinse away any of the ammonia and alcohol mixture. Dry the window using a squeegee and it should be clean.
If you still have etched glass, you may want to consider getting replacement windows installed in your home. If so, clean your windows regularly with a chemical solution made for this type of stain or the vinegar and water solution above to keep the stains off your windows.