hone lapping question

I have an old hone that is about 2000 grit, I'm guessing. It has always been the hunting knife stone and has a pretty good "dish" in the middle on both sides. While I was lapping a couple of other stones yesterday I gave this one a try. Holy crap, after about 45 minutes it looked like I had barely done anything at all. It also didn't "feel" like the sand paper was doing much. Oh, yeah I was lapping on a granit surfacing slab with 600 grit wet/dry paper and plenty of water. My question is this, Is there a way to get this stone closer to flat without damageing it, either by mahcine or maybe lower grit sandpaper, and then finish by hand lapping. Otherwise it looks like it may take me about 12 hours to do the job by hand with 600 grit. This stone is low grit but seems harder than my chinese 12k stone.

You could drop down to #220, #120 or #80 grit sandpaper. That should speed things up a little. You can also use a lapping plate, either diamond coated or one with lapping powders.

Just think about how long it collectively took to make the dip, and that's about how long it will take to remove it!

600 grit is quite high for lapping. I think somewhere around 325 is considered standard, and going lower for serious removial is highly recommended. You can swap out for a fresh sheet when the current one doesn't seem to be cutting as well.

It may, however, be a better use of your time/money to simply buy a new one for your razors and keep that one for your knives.