Can you resurface brake discs on a wood lathe?

My car needed new brake pads, and the mechanic said they always replace the discs (rotors, for North American viewers) at the same time to avoid uneven wear, squeaks or poor braking. My discs weren't warped or cracked, just glazed. Swapping out a perfectly solid lump of metal because its surface has lost its edge felt like buying a new knife because yours has gone blunt, so I wanted to know if I could sharpen it instead, by resurfacing the brake discs at home on my wood lathe.

Why a wood lathe?

Professional skimming exists but is usually expensive and aimed at high-end cars. The DIY methods I found mostly involved jacking the car up and running it in gear while working on the spinning disc underneath, which I wasn't keen on. But I do have a wood lathe, and it spins things. If I wanted an even resurface, the disc needed to spin, so this video is an experiment in doing it at home with less sophisticated tools.

Resurfacing the discs with an angle grinder

With ear, face and hand protection on, I mounted the disc on the lathe and started with an 80-grit flap disc on the angle grinder to take off the rust and attack the worn lip around the edge. That wasn't aggressive enough, so I switched to a grinding disc to remove most of the lip, being careful not to take off too much metal. I tried two approaches: holding the grinder switched off and letting the lathe spin the disc against it, and running the grinder while turning the lathe by hand. The second was far more aggressive and removed material faster.

I tried 120-grit wet-and-dry on a wooden block to flatten the minor grooves from the pads, but it wasn't designed for metal and made little difference. Back on the flap discs, I went down to 40 grit to bring the whole face level with the lowest groove, finished at 80 grit, and checked for high and low spots with a straight edge as I went. The disc ran impressively smoothly on the lathe.

A safety scare, and the result

One unsettling moment: on the second side the chuck came loose. I think the grinder spun the disc faster than the lathe was driving it, which started unscrewing the chuck from the motor. I caught it immediately, stopped, sorted it and carried on.

The result isn't a factory finish or what you'd get on a proper metalworking lathe, but if it gets more life out of a perfectly usable part, I call that a win. This is an experiment, not professional advice, so please don't try it unless you understand the risks and take proper precautions.