This invention relates to methods and materials for slip ring grinding of a generator rotor, without the need of dismounting the slip ring from the rotor of the generator, and allowing the grinding process to be performed whilst the generator is on full-load operation. As such the methods and materials of the present invention differs from current solution. Whilst allowing on-line grinding of the slip ring, the current solutions require low-speed rotations and accordingly operational shutdown of the generator. Allowing on-load grinding, the present invention greatly shortens the downtime of the generator and to perform maintenance on the slip ring beyond the provided standard maintenance schedule.
