Thickness behind the edge

[mark76]

yeah.. they are time consuming. I use my big wheel to thin, then refinish on the belt grinder and buffer. By hand, they take forever. Better than the diamond, the 220 grit stones work wonders on these kinds of steel.

Jon, if you ever want to do a video again... I'm considering to get a (cheap) wheel which I'll primarily use for thinning. But I have no idea to properly use a wheel for regrinding...

 

[CaremeFraiche]

I can't help but think that reading through these posts that almost all knives need some kind of thinning and that Japanese knives in general are inadequate unless they have been ordered to the specifications of a particular vendor. There has to be some level of objectivity in these discussions. There a lot of opinions and commentary that seem to be self serving.

 

[rick alen]

I can't help but think that reading through these posts that almost all knives need some kind of thinning and that Japanese knives in general are inadequate unless they have been ordered to the specifications of a particular vendor. There has to be some level of objectivity in these discussions. There a lot of opinions and commentary that seem to be self serving.

Not necessarily so about the suppliers and vendors, but yes, all knives need thinning, eventually. Self serving/lack of objectivity????

You have everything from lasers to work horses. Often people thin a knife because they decide they want something more like a laser. But any knife that gets sharpened is eventually going to need thinning, regardless. Its a simple fact of geometry. As you sharpen the primary bevel moves up and given that the secondary bevel is some kind of angle this means the thickness behind the primary bevel I going to get thicker.


Rick

 

[AllanP]

Not necessarily so about the suppliers and vendors, but yes, all knives need thinning, eventually. Self serving/lack of objectivity????

You have everything from lasers to work horses. Often people thin a knife because they decide they want something more like a laser. But any knife that gets sharpened is eventually going to need thinning, regardless. Its a simple fact of geometry. As you sharpen the primary bevel moves up and given that the secondary bevel is some kind of angle this means the thickness behind the primary bevel I going to get thicker.


Rick

the idea of thinning scares the hell out of me. I want to strop as much as possible to not wear away as much steel in each session

it seems like even with the right equipment it's very labour intensive and I still probably would mess up somehow and send it someone to fix it

 

[mhpr262]

the idea of thinning scares the hell out of me. I want to strop as much as possible to not wear away as much steel in each session

Just practice with some cheap, industrial stainless knives beforehand. I have by now thinned a few of those on my belt sander and the results were quite impressive. It makes a huge difference in how the blade glides through the food. I now have a few 10-15 dollar knives that cut like knives ten times their price.

It helped with my nervousness about thinning, too. I'm not quite ready to take on thinning some $500 knife yet, though, but I keep practicing ... :biggrin:

 

[Benuser]

the idea of thinning scares the hell out of me. I want to strop as much as possible to not wear away as much steel in each session

it seems like even with the right equipment it's very labour intensive and I still probably would mess up somehow and send it someone to fix it

You will end with a lot of fatigued steel that won't hold any edge.

 

[mhpr262]

If you look at Jon's videos the thinning is built in into single bevel knives sharpening. You move the shinogi line up a bit, then sharpen the secondary bevel to the edge, then blend together the two.

So you are just removing the fatigued steel and moving the whole configuration up.

Thinning a Euro style knife with completely flat bladefaces and an (ideally) very small cutting bevel is a very different sort of undertaking though. I wish Jon would make a video on that ...

 

[Benuser]

So you are just removing the fatigued steel and moving the whole configuration up.

Very well put indeed.

 

[_PixelNinja]

the idea of thinning scares the hell out of me. I want to strop as much as possible to not wear away as much steel in each session

it seems like even with the right equipment it's very labour intensive and I still probably would mess up somehow and send it someone to fix it

It scared me too at first (I am OCD about messing things up) but I took a deep breath and just went for it since it is a necessary part of knife maintenance. As long as you are observant and understand what is going on, it should not be that difficult to get good results. I find the hard and most time consuming part to be refinishing the blade rather than the actual thinning.

In regards to stropping, I agree withBenuser — you don't want to over do that.

 

[rico]

I measured the angle of the bevel on some of my knives. It ranges from 1.7 - 1.8 degrees to 3.8 - 4.0 degrees. The higher angle knives are kind of expensive and known to be quit thin behind the edge and they do cut like a dream. My conclusion is to find a way to thin at about a 3.8 degree angle. I'm thinking of a belt / disc sander combo that could be used to grind a jig with the disc at the correct angel and then use the jig to hold the knife at the proper angel against the belt. Another advantage of this method would be to retain more of the original surface finish, such as damascus or pear skin for example. Any thoughts?

 

[turbochef422]

At first thinning was a scary thought with a lot of trial and error all I can say is don't over think it. I wouldn't worry about exact angles going by feel is the way to go. Now I thin somewhat every time I sharpen. I start just above where the bevel starts and work my way down to the edge. Going alittle higher each time I sharpen.

 

[Keith Sinclair]

At first thinning was a scary thought with a lot of trial and error all I can say is don't over think it. I wouldn't worry about exact angles going by feel is the way to go. Now I thin somewhat every time I sharpen. I start just above where the bevel starts and work my way down to the edge. Going alittle higher each time I sharpen.

Exactly:thumbsup: Thinning a little behind the edge keeps a knife cutting well. The thinning sets you up for your final bevel.

 

[Benuser]

Have your stone flat, and keep the relief bevel as low as you can.

 

[Keith Sinclair]

Akifusa SRS-15 took a fair amount of steel off lower blade face. Enough for me anyway
Sanded to 320 kind of satin finish needs some more work. Dropped the heel on handle like JMO think it improves the lines always liked Randy Hass handles.

 

[spoiledbroth]

Nice work!! Love what you did with the butt of the handle. :thumbsup:

 

[krx927]

Akifusa SRS-15 took a fair amount of steel off lower blade face. Enough for me anyway
Sanded to 320 kind of satin finish needs some more work. Dropped the heel on handle like JMO think it improves the lines always liked Randy Hass handles.

Can you make another pics of the coil with the ruler like in my first post to be able to compare it directly?
Thanks!