A common sharpening problem (buffesr)

RobbW · Dec 8, 2003

Originally posted by Cliff Stamp
pendentive :

The two biggest problems I have seen come from the same source, asking the buffer to do too much sharpening....Now instead of going to a higher grit belt to refine the edge go right to the buffer with a high polish load and use it to try to get a mirror polish.
-Cliff

My EdgePro jumps from 600 right up to a 3000 polish tape. Should I get something in between to avoid such a jump in grit?

thombrogan · Dec 8, 2003

Originally posted by KnifeRat
Should I get something in between to avoid such a jump in grit?

Actually, at the 600 grit stones, your blade should be fairly well polished and more than ready for the 3000 grit tape. Assuming your coarse and medium stones have been flattened after repeated uses (something I'm overdue for), the biggest places to make sure the job is done are between coarse, medium, and fine. After you've made a smooth transition from medium to fine, it's really easy to go onto extra-fine, ultra-fine, and then the tapes.

RobbW · Dec 8, 2003

Thanks Thom! I've had a blast learning to use my EdgePro. I started with large kitchen cutlery for practice, then felt confident to work on my BM940D2 and it came out beautifully twice so far. Just got a small Sebenza classic today and I almost can't wait for it to dull so I can try my hand sharpening it as well.

Nosmo · Dec 8, 2003

I am enjoying this thread, but still believe that so much
time and effort in sharpening could be saved by
following the old maxim, " Raise a burr on each side before
moving on to the next step".

This one simple statement I learnt many years ago is as valid today as it was then.

So many folk spend a huge amount of time, sharpening their secondary
bevels,and not their edges.

Nosmo · Dec 8, 2003

Originally posted by KnifeRat
My EdgePro jumps from 600 right up to a 3000 polish tape. Should I get something in between to avoid such a jump in grit?

I have been experimenting with intermediate grits between
600 and 3000. Edge pro sells the extra blanks but so far I would agree with Thom that I have found no need for this extra step.

If your 600 grit has worked out the scratches from previous
stones, then the jump from 600 to 3000 is OK.

The above is true for the Edge Pro supplied grits and tape.
I believe their grading system is proprietary and should not be compared to more general grits.

thombrogan · Dec 8, 2003

Originally posted by Nosmo
The above is true for the Edge Pro supplied grits and tape.
I believe their grading system is proprietary and should not be compared to more general grits.

I'm inclined to agree. The edge gets all mirrory-looking at the 320 grit hone, which doesn't compare with my experiences with sandpaper or 400 grit diamond hones.

JDBLADE · Dec 8, 2003

It really depends on what use a Knife is to be put to but it still does come back to the basics and that is to raise those burrs however microscopic they might be. This is the way meatworkers break in their knives and they work with them all day.

sabit · Dec 9, 2003

Does this mean that when sharpening high end steels like S30V, waterstones are useless?

Or it it cause by the dished on the stones?

thombrogan · Dec 9, 2003

Originally posted by sabit
Or it it cause by the dished on the stones?

Dished waterstones won't behave as intended, but flattened waterstones work like crazed sharpening badgers on S30V and similar steels.

Roadrunner · Dec 9, 2003

Thom's eloquence and experience speak yet again.

Couldn't have said it better myself.

panella · Dec 9, 2003

Cliff,

Thanks for the informative post.

I have experienced the exact problem you described sharpening an S30V blade. It never occured to me that a little dishing might be responsible for the mixed results I was getting. I'm going to make sure my water stones are "true" more often.

Is there any reason that minor "dishing" would affect "softer" steels less than harder alloys like S30V? Or at least be less noticable? I realize it could be technique, but I've really only experienced this problem on S30V.

RobbW · Dec 10, 2003

If I work the blade up to 600 grit waterstone or even 3000 grit polish tape, will it benefit from using a smooth steel, or it that a high enough grit that the steel doesn't really make a difference?

Then later after the blade's seen some use, would it benefit from the steel, or should I just go to the 300 or 600 waterstone for the touch up?

Cliff Stamp · Dec 10, 2003

panella :

Is there any reason that minor "dishing" would affect "softer" steels less than harder alloys like S30V? Or at least be less noticable?

Yes, S30V is one of the more difficult to machine steels and as machinability drops the demand for solid technique goes up. Lets assume that the edge on a 1095 blade needs 2 passes per side to reset it, and due to variance in the passes this takes five times that long because not every pass is hitting the edge - this is still only 10 passes per side.

With S30V since the machinability is so much lower lets assume you are looking at 10 perfect passes, with the same deviations this is now 50 passes per side. Since frustration starts to set in with extended honing technique will start to break down even more, not to mention effects of fatigue and the stones continuing to dish out with extended use.

So instead of comparing 2 passes per side to 10, both of which are just seconds, you end up comparing 10 passes per side to 200+, this ends up labeling S30V as a horrible steel for resharpening if it ever gets sharpened at all.

KnifeRat :

If I work the blade up to 600 grit waterstone or even 3000 grit polish tape, will it benefit from using a smooth steel

Nothing benefits from using a smooth steel as a finishing step. This weakens the edge and lower the edge retention significantly.

Then later after the blade's seen some use, would it benefit from the steel, or should I just go to the 300 or 600 waterstone for the touch up?

You will get much better edge retention after resharpening with the stones, however the steel is much faster to use.

-Cliff

RobbW · Dec 10, 2003

Thanks Cliff! I've got a couple sharpening books on order so I can help educate myself to more completely understand the processes that work.

panella · Dec 10, 2003

Cliff,

Thanks for that great answer. Now I've got a microscope, a lot of useful information and more patience.

-Paul