How to strip off decades-old CDA adhesive
Method 1: Very old adhesive can be the most stubborn to remove. First, try a quality adhesive remover with a sharp blade. If you don’t have access to a high-quality adhesive remover, sometimes paint thinner, acetone, or oven cleaner will actually do a better job than the adhesive remover itself. Method 2: If scraping with an adhesive remover doesn’t work, try using a steamer on the glass before scraping. Method 3: Another option is the garbage-bag method. First, thoroughly soak the glass in whatever you want to use to remove the adhesive - whether its oven cleaner, ammonia, paint thinner, etc. After the soaking, cover the glass with a garbage bag by taping it down around the perimeter of the glass. Let it sit for about 1-2 hours. This method works best in the heat or sunlight. Take the garbage bag off the glass and then start the scraping process. It should be a lot easier to peel off the adhesive after this process. Method 4: If none of your prep methods are working, change your scraping technique and try doing it dry. Using a 4-inch stripper blade held at a 45-degree angle from the glass, scrape diagonally at 45 degrees. Don’t use any water and use the same wrist motion you would when filleting a fish.