Blade runner

QI saw an advert for wiper blade cutters, which put a new edge on worn blades. Are these any good?

Edgar Moran, Blandford Forum

AWe’d suggest they’re probably not much use in real life. By the time the edge has worn off the blade, it’s time to replace it. The surface layer of the rubber will be disintegrating and the blade will probably have lost its suppleness, which will cause juddering and noisy operation.