Great to see you back Ian!
Originally Posted by SliceOfLife
I think the OP's not hitting the edge of the edge. Grinding away enough metal to cancel out a layer of tape can take a long time on a slow stone.
45 minutes really says nothing on a1K Norton, it's slow to begin with & glazes & clogs after 30 seconds....after that it's useless IMO.
Paint the whole edge with magic marker & have at it with 1 layer of tape. Check the edge after a bunch of laps. If you are hitting the edge all marker all over the edge should be gone.
Otherwise, have at it for as long as it takes. Lap the Norton often & leave the slurry from the lapping on it, that speeds it up a notch. Dont stop until all of the blade shaves armhair with ease & passes the TNT. Then you are ready to move on.
Can-can scratch patterns!