Q My tablet slid off my lap and on to a concrete floor. Everything still works, but now the screen’s acquired a bunch of scratches. Is there any way to fix this?
A I wasn’t able to find a commercial product that claims to fix scratches on a glass touchscreen, but a Google search turned up a variety of improvised remedies. These run the gamut from fishy to believable, but have one thing in common: a neartotal lack of substantiation. I decided to sacrifice a disused iPhone 3G for testing, a process that started with a pair of keys and ended, painfully, with a screwdriver.
One standout claim is that a coat of Turtle Wax will minimise scratches; in my testing, it did nothing of the sort, and left behind a thin film of wax, which attracted fingerprints. Others point to 3M scratch remover for cars as a possibility; three rigorous applications did nothing for the iPhone. Displex, a polish for plastic screens and another favourite among online DIYers, left the screen immaculately shiny and seemed to darken the appearance of scratches, but this was a temporary effect of lingering residue. I even scrubbed the screen with toothpaste until my arm was sore, which had no lasting effect.
There is, of course, an extreme option: glass buffing. With a small drill attachment and a tub of cerium oxide compound (and for deep scratches, some sandpaper), it is possible to grind scratches out of a screen, the same way you would buff scratches out of automotive glass. My testing indicates that this is a very bad idea. Glass grinding requires the steady application of wet-mixed cerium oxide, which is quite messy, and sprayed water, a natural enemy of all things electronic. I attempted to seal the phone with tape, but the sticky cerium slop found its way into almost every opening, drying like a fine cement.
As for the scratches, I was just starting to see improvement when I noticed a new type of blemish. My inconsistent water application had resulted in overheating, which destroyed an area of the underlying LCD. For a touchscreen device, glass grinding is, in other words, overkill, with an emphasis on “kill”. The best solution, short of screen replacement, is a screen-protector film. It won’t just shield from future scratches – it will make some shallow ones invisible.