Originally Posted by
Euclid440
Sounds like contamination, especially since you are using sandpaper. I would first clean your stones with cleanser and a scotch-brite pad and rinse and scrub again with the scotch-brite under running water.
Then take a straight edged kitchen knife and run the knife slowly over the stone to detect any snagging grit. A large knife may dislodge the imbedded grit. Also as recommended insure the edges are well beveled or rounded.
If you use wet and dry, (I use W/D lapping natural stones) use quality paper.
Lastly, bite the bullet and purchase a diamond plate, if you are going to hone, a diamond plate will make your life so much easier and give you consistent surface on your stones.