Search:

Even if the hone is flat, if it's between 1.5 and 3" wide, he will form a frown in the long run for exactly the reason he stated. The middle of the blade spends more time on the hone than the ends....

BTW, the best way to hone on the yellow, IMO, is to create a slurry. You do this with a rubbing stone, or if you don't have one, you can use flat pumice or a babrer hone. Once the slurry looks like...

You may not be able to get it at an ordinary hardware store. I know Sears has it. Or you can get from an auto parts store that has body repaier supplies.

Ilija (Firestart) has the right idea. Tape the spine, put some 1K sandpaper on a glass top of plate or heavy tile, and hone away, with both the spine and edge touching the sandpaper. Keep checking...