Old-School Alarm Question: How Do You Remove Foil Tape From Windows?

Incidentally, I have a house which had tape on some top windows as well, and it came right off without these issues, so not sure the difference in these installations.

There were two options for foil, IIRC. Some of it was self-stick and all you needed. Other versions had a sort of varnish that you applied over the top.

I think you had the self-stick and your friend has the lacquered version. Try acetone/nail-polish remover first.

It sounds like an urban myth, but try WD-40. In chemistry, 'like dissolves like', so a mild oily solvent can reactivate the petrified adhesive and make it pliable enough to scrape off easier.

Goo Gone + Razor + Hair Dryer

I've used a razor blade and Windex. Alcohol cleans oily residue from glass too. But it sounds like the glass has been etched somehow leaving visible lines. I saw a window cleaning service use a pumice block to remove a bad scratch on a window. It took them a lot of rubbing before the scratch was gone. They used a liquid to work the pumice, but I don't know what type of liquid, maybe just water. You might call a window washing company and ask what they recommend.

Just did a search and found a few sites that talk about restoring etched/scratched windows. Some recommend "fine pumice" and a host of other solutions. I think pumice can be obtained in a block or stick form. Pumice is used to clean stains on porcelain too.

If the tape is coated with lacquer, spray it with Windex, wait 5 minutes, and then scrape it off with one of these things. If the tape is not coated with lacquer because it was installed by an incompetent, then just use the scraper. Slice the tape across to create a notch for the razor. Hold the razor at a 30 degree angle, and slooooowly scrape upwards in a smooth, not jerky, motion. You'll probably need a few passes to get the glue off. After you get most of it off, spray the window with Windex and clean it off.

When I foiled Windows we used a little Elmers White Glue mixed with water to adhere the foil and then coated with varnish.

Razor blades take the tape and varnish off. The rest?

The guy who foiled these decided to add some decorative features.