Why use a glass polish
Glass is softer then you might think. It will get damaged by stones thrown up by the car in front of you, the wiper moving over the window, you scraping off the ice in the winter etc. And the scratches it causes, are very difficult to remove. A normal polish isn’t rough and strong enough to polish glass. Most normal pads are also to soft. Specialized glass polish (and a glass polish pad) is composed from different ingredients, and has much more effect on glass.
Polishing glass is also a very effective way of deep cleaning the glass. This will help a lot in the preparation for a glass sealant/coating.
Some people think they can have just as much result on glass as they have on paintwork. But this is not the case. Removing a scratch is done by removing as much paintwork as the depth of the scratch. But with glass, this would mean that you have to remove a few microns. And this takes a lot of effort. It would not be realistic to expect to have a perfect window. You might make the wiper-streaks less visible, but these won’t be removed. If you have a serious scratch or deep imperfection, you won’t be able to remove this, at most you’ll make it less noticeable. Just because there is a glass polish, don’t expect to much. The results will generally be that you have made things less noticeable, but not removed.
Things that can go wrong
When polishing glass, you’ll need a rotary and a fair bit of experience. Polishing the glass will create heat, and to much heat can crack the glass. You also need to apply pressure on the glass, and to much pressure can also break the glass. Putting way to much time and pressure at one certain point can potentially lead to a slight bending of the light. This won’t be very much, but in some very extreme cases it can be noticed. But even in that case, it will be very slight and only noticeable in certain circumstances.
A short list of wrong thinking.
- You can correct the glass for 100%
- Polishing will make the glass act like a fun-house mirror
- You will cause only damage
- Polishing will make it
Things to keep in mind
Although a glass polish isn’t extremely difficult to use, it needs to be applied properly to have the most effect. You can read the How to polish glass article, or you can ask your manufacturer for more information on the subject.