New Angle Grinder for Kiln Shelf Cleanup - Paddle or Slide Switch? in Equipment Use and Repair Posted June 30, 2019 · Report reply I’ve had plucking at cone 6/7 using high alumina kiln shelves without wash. I always wash the shelves used by our students but keep a personal set for my own work. I never washed those... just marked them A side and B side with RIO and alternated sides for glaze firings to prevent warping. After a while I started getting plucked feet so I started kiln washing. If there’s something else I can do to prevent plucking please let me know. I’d much prefer to not use kiln wash. Grinder update: I bought a $40 Bosch corded grinder with a slide lock switch. It’s probably in my head and makes no difference, but knowing how wrong things can go with an angler grinder I felt better going with a brand I know and trust.