Sharpening beyond #1000

[Bo-dacious]

Hi guys. I just got a new 4000 grit stone and I tried it for the first time. It made no difference from 1000 grit. That is to say it made it no sharper. What am I doing wrong? Should I be pressing lighter at this grit? I pressed the same hardness as 1000# is that what I did wrong?
Please help.

Thanks,

Bo

 

[jc57]

Assuming you had a fully apexed, burr free edge of the 1000, then a 4000 if used properly won't make the edge sharper per se, it will just make the edge bevel smoother.

 

[DeadboxHero]

Use extremely light pressure, build a slurry with your stone flattener and imagine sharpening by riding on and through the mud.

Polishing the edge on a finishing stone only enhances the work you've done at lower grit

If you didn't build a solid apex at the lower grit then there is nothing to gain at high grit except a shiny bevel.
Also,
you always take a risk of rounding your edge due to angle inconsistencies or too much pressure when using a polishing stone.

Hope that helps you troubleshoot.


Also keep in mind that you reduce the edge life when you polish the edge but you enhance the precision and quality of the cut. Always a trade off just depends what the knife is used for.

 

[miso2]

Also keep in mind that you reduce the edge life when you polish the edge......

Can you elaborate on this a bit? I understand that coarse edges generally keep slicing aggressiveness longer than polished edges. Do you refer to this or something else? I am just curious and willing to learn.


Miso

 

[DeadboxHero]

in general, high polished edges don't CUT as long as coarser edges.

but are SHARPER, I very much prefer polished edge but it comes at a cost to the utility use of a knife, especially if the quality of the cutting is not as important as the overall endurance.

thats why its great to find the right balance between the steel and abrasives and geometries for the top performance for the given task







this is a vast subject with tons of variables though.
steels, abrasives, proper apex formation, proper deburring

too much to discuss without more specific questions to narrow it down.

 

[miso2]

Thank you for the clarification.

Miso

 

[HeavyHanded]

Use extremely light pressure, build a slurry with your stone flattener and imagine sharpening by riding on and through the mud.

Polishing the edge on a finishing stone only enhances the work you've done at lower grit

If you didn't build a solid apex at the lower grit then there is nothing to gain at high grit except a shiny bevel.
Also,
you always take a risk of rounding your edge due to angle inconsistencies or too much pressure when using a polishing stone.

Hope that helps you troubleshoot.


Also keep in mind that you reduce the edge life when you polish the edge but you enhance the precision and quality of the cut. Always a trade off just depends what the knife is used for.

This ^ :thumbup:

 

[Jason B.]

Good advice but I would never recommend building a slurry on a waterstone unless you know exactly why you are doing it.

The slurry will do almost nothing for the sharpening of standard knives and can negatively impact the sharpening, especially if a lapping stone/plate/Nagura was used to create it. I've learned over the years that if you can't build a slurry/mud on the stone from the sharpening process then it was never meant to happen.

When sharpening on waterstones the surface should be well flushed with clean water at all times.

 

[HeavyHanded]

Good advice but I would never recommend building a slurry on a waterstone unless you know exactly why you are doing it.

The slurry will do almost nothing for the sharpening of standard knives and can negatively impact the sharpening, especially if a lapping stone/plate/Nagura was used to create it. I've learned over the years that if you can't build a slurry/mud on the stone from the sharpening process then it was never meant to happen.

When sharpening on waterstones the surface should be well flushed with clean water at all times.

Normally I only work with the slurry created by sharpening, and then, yes, I rinse it often. With the exception of cosmetics, I haven't found a slurry to help sharpening.

An exception to this might be a coticule, as there are established strategies used on them. Waterstones and friable oil stones do best with a slight slurry when grinding to a burr, then rinse often for finish work.

My opinion on this has changed a couple of times...

It would also help maybe to know what brand of 4k the OP is using.

 

[Bo-dacious]

Ok thanks guys. So I should clean off the slurry as I go to make it sharpen better?? 8 was told to make a slurry I'm confused. I'll try keeping it clean with water and using light pressure.

Thanks again,

Bo

 

[DeadboxHero]

Good advice but I would never recommend building a slurry on a waterstone unless you know exactly why you are doing it.

The slurry will do almost nothing for the sharpening of standard knives and can negatively impact the sharpening, especially if a lapping stone/plate/Nagura was used to create it. I've learned over the years that if you can't build a slurry/mud on the stone from the sharpening process then it was never meant to happen.

When sharpening on waterstones the surface should be well flushed with clean water at all times.

I like the slurry, evens out my finish and reminds me to use light pressure. When I don't use slurry I get streaks in my finish especially on hard stones like the Naniwa Professional.If I was a better sharpener then I wouldnt need the mud to fill in the gaps on my inconsistencies.

But hey, it's a small bevel, no one can tell

 

[HeavyHanded]

I like the slurry, evens out my finish and reminds me to use light pressure. When I don't use slurry I get streaks in my finish especially on hard stones like the Naniwa Professional.If I was a better sharpener then I wouldnt need the mud to fill in the gaps on my inconsistencies.

But hey, it's a small bevel, no one can tell

This is why I say I've gone back and forth on this one.

A safe bet is to keep it rinsed, but I have definitely been in situations where the mud helped with the streaks/hammertone from very hard stones. That's why I added

With the exception of cosmetics

I'm sort of lucky in that the harder waterstones I own exhibit sticktion if I use even a tiny bit too much pressure, resulting in hatching. This is a lot like working with diamonds on woodworking tools with wide bevels - is not easy to get the cosmetics good.

The other hard stones I own do release a bit of slurry and I still maintain this is a good thing up to the burr/bevel setting stage. After that I like to rinse it clean even on softer stones where I'll be finishing with a trailing pass. Clean up and refining on a clean stone for the most part.

 

[Tim the Wizard]

Strop on it.