Loosing sharpness as I progress

[Marc H]

Mikeyv wrote:

I have noticed that re profiling takes a realllllllyyyyyyy long time!!!!

Just for me, when I find it’s taking too long I step down to a coarser stone to remove metal quicker. Of course I get deeper rougher scratches to contend with. I wore out my 800/1000 diamond stone fast before I learned this. I find when my edge isn’t feeling sharp as I progress it’s what Tom suggested, that I hadn’t sharpened to the apex. A microscope helps to see what I’m doing but nothing replaces feeling the edge, for me. Also I do check my stones with an angle gauge each progression even if I’m just flipping it over. I think a few tenths to a half a degree off may make me miss the apex. And when it’s not getting sharp my tendency was to continue sharpening longer with that stone hence removing more metal than was necessary.

I generally use scrubbing strokes an leading edge mostly, changing directions as I progress through the paddles to see how well I’m removing the last scratches and, of course, trailing strokes with the lapping films and strops.

Marc
(MarcH's Rack-Its)

[NotVerySharp]

Care to guess in how many hours, years, knives, strokes, anything, how long your diamond stone lasted?

[Marc H]

NotVerySharp wrote:

Care to guess in how many hours, years, knives, strokes, anything, how long your diamond stone lasted?

They lasted about 2-1/2 years, lots of knives and lots of strokes. Trying to sharpen super hard new fangled stainless steels when I should have stepped down to coarser grits was probably their early death. Hence my earlier advice. Now as soon as it seems I not making headway or having to exert too much pressure I try going lower grit and look how that’s working.

Marc
(MarcH's Rack-Its)

[tcmeyer]

I’ve always felt that edge trailing strokes had a tendency to break off chunks of the edge.  Clay did some microscope studies this last year which pretty much confirmed it.  But do I only use edge-leading strokes?  Not necessarily.  With lower grits (400/600) I’ll often use scrubbing strokes, but apply more pressure on the down-stroke (edge leading) than on the up-stroke.  Depends on how impatient I am.  With the 100/200s (which I very seldom use) I’ll go strictly edge leading.  The chunks these babies will tear out are really nasty and take a really long time to remove.  With 800/1000s, or higher grits, I think there is less of a tendency to break out chips/chunks from the edge, so I won’t necessarily stick to edge-leading, although higher magnifications might prove me wrong.

Please note that I do not use alternating strokes except on the last five strokes or so for the final grit.  The size of the burr is dependent on the grit and the number of strokes you’ve taken on one side. Alternating strokes pretty much eliminate any trace of a burr.  I don’t think I’ve ever raised a burr that was large enough to hook my fingernail on.  Of course, I bite my fingernails so that’s a moot point anyway.  You can feel even a very small burr with your fingertips.  But with finer grits the burr will be barely detectable by feel.  On a USB microscope, a burr will appear to be a very thin, bright line along the apex.  Usually, only a few, light strokes on the opposite side will knock off the burr.

FWIW, I prefer to use single-sided strokes because of a neural deficit I have.  I am on Tramadol for nerve pain and this deadens my sensitivity to touch and my eye-hand coordination.  Single-sided strokes are just easier for me.  Ain’t nobody gonna talk me out of my Tramadol.  If you do the alternating stroke thing, it’ll be hard to detect any burr.

[dulledge]

Mikeyv wrote:

I have noticed that re profiling takes a realllllllyyyyyyy long time!!!! Might start doing it in smaller steps over different snarling periods or just take it to the belt sander

Yep. That is another theory that you possibly didn’t reach apex with your first lower grit. All consecutive grits didn’t sharpen the edge then. It is very important to reach apex with your first stone.

It is confusing though. You said that edge was very sharp at 600 grit. So it is pretty puzzling in what you are saying.

[tcmeyer]

dulledge wrote:

Mikeyv wrote:

I have noticed that re profiling takes a realllllllyyyyyyy long time!!!! Might start doing it in smaller steps over different snarling periods or just take it to the belt sander

Yep. That is another theory that you possibly didn’t reach apex with your first lower grit. All consecutive grits didn’t sharpen the edge then. It is very important to reach apex with your first stone. It is confusing though. You said that edge was very sharp at 600 grit. So it is pretty puzzling in what you are saying.

I should qualify my position on this.  By the first or lowest grit, I mean the first grit that forms an apex.  I try to never touch the apex with grits lower than 400.  They can do a lot of damage that can take a lot of stoning with the 400 to clean up.

Depending on your perspective, 600 can produce a very sharp edge.   Which is why WE includes only 100/200/400/600 grits in the base package.  If you’re cutting rope, it might be just what the doctor ordered.  I once read a testimonial on Josh’s RazorEdgeKnives.com site where the customer was absolutely delighted with his 600-grit sharpening job.

 

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dulledge

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