How do I know when I need to learn more skills (thinning/polishing etc.)?

[Gongoozler]

I’m currently confident in my ability to perform edge sharpening on all of my knives. However, that’s all I know how to do. I’ve never thinned a blade, never polished a blade, etc.

Other than saying to myself “hey, this knife doesn’t cut like it used to” followed by looking at the choil and looking at the thickness BTE, what other indicators might there be to tell me it’s time to learn a new sharpening/maintenance skill?

 

[HumbleHomeCook]

So I would strongly encourage you to separate thinning and polishing. They are very different things with different goals. Polishing, by and large, is cosmetic and fully optional. Polishing is very, very involved and is truly a passion project. I have a lot of respect for those who pursue it but I recognized early on that I am not among them.

Thinning is functional. Thinning can mean altering the blade as it is presented to something more to your liking/requirements to use or the maintenance of the blade over time. Sounds like you're interested in the latter right now and that's good.

Abuse the forum search function. You should find some good discussions on thinning. But here is my personal take. Don't stress it.

Maintenance thinning is basically broke into two camps: 1) A little each time we sharpen. 2) Wait until it needs it and do it all at once. There's no right or wrong answer, just what you want to do. But it's also a little broader discussion in that you should have good routine edge maintenance program and that greatly prolongs the need for thinning no matter how you want to approach it.

If you lightly maintain your edge, and then do a periodic full sharpening, you can go a long time without needing to thin. And depending on your use case, I'm talking potentially years.

So, I think the first question to answer is if you have that good "gentle" maintenance program set and if you have it adjusted for your different knives. We don't always have to treat all of our knives the same. Maybe you like a certain edge on a certain knife or you use a knife more than the other or whatever. Focus here first and maybe you have.

I think sometimes we make more of maintenance thinning than it really deserves. I count myself guilty there sometimes too. Should we be aware of it and understand it and have a plan for it? Yes. Is it really pressing? No.

Thinning for blade modifications, again, is a different thing. I mean, the basic concept is the same but the motivations are different.

I tend to fall more into camp #1 from above with most of my knives. Meaning, when I do a full sharpening, I do a little thinning each time. I generally don't mess with thinning on routine edge maintenance.

One of the best pieces of advice I think can impart to any newish sharpener is to let the specific knife and yourself tell you what is needed. I know that sounds simple and cliche but it is true. Nothing any of us says trumps what your blades and your preferences are telling you. Listen to those voices and be guided by them. If it doesn't need something, then don't do it.

Oh and the other thing is, you can always take off, you can't put back on.

 

[HumbleHomeCook]

I should also add, that thinning blurs into polishing or cosmetics if you want to maintain a look of your given knife. Meaning, as soon as you start thinning, the looks will be very altered. You'll need to decide if you're okay with that and if not, what to do about it.

 

[M1k3]

Hope you can see what I mean in these pictures.

First knife. Kind of thick behind the edge. Look at the width of the shiny part along the cutting edge. Could use a thinning.

This next one is quite thin behind the edge. The shiny part of the level is barely visible. Doesn't need thinning.

Hope this gives you a good visual idea of when to thin.

 

[KasumiJLA]

I think that from a certain point thinning is not so far from polishing. Obviously thinning is to improve the performance of the knife but when the work is done, it is often there that the visual of the knife leaves something to be desired. Of course you can leave a knife with scratches from a 120 stone and use it that way. I myself have knives that are ugly but cut well.

But, without going overboard, it is after thinning that you can have fun making, let's say, a kasumi effect with your different synthetic stones. If you don't like that, because it still requires time and practice, at least you will know that you are a lover of performance rather than aesthetics. At least you can give it a try and see if you like it.

Oh, and @HumbleHomeCook summed it all up very well!

 

[aporigine]

Hope you can see what I mean in these pictures.

First knife. Kind of thick behind the edge. Look at the width of the shiny part along the cutting edge. Could use a thinning.View attachment 347952


This next one is quite thin behind the edge. The shiny part of the level is barely visible. Doesn't need thinning.View attachment 347953


Hope this gives you a good visual idea of when to thin.

In re the first knife — how far toward the spine should metal be removed to count as a proper thinning?

My impulse is to say “all the way”, backing off only to accommodate bolster or handle transitions. Exception: rendering an initially flat grind subtly convex.

 

[M1k3]

In re the first knife — how far toward the spine should metal be removed to count as a proper thinning?

My impulse is to say “all the way”, backing off only to accommodate bolster or handle transitions. Exception: rendering an initially flat grind subtly convex.

Kind of hard to say. Depends on how thick it is to begin, what the knife is and used for.

If it's thick all the way up to the spine and wedges like crazy, I'd thin up to the spine. If it's a thinner knife that's just thick behind the edge, I'd thin up to about 1/2 inch or so behind the edge.

In my example, it's the cheapest Mercer. I use it to loan out and be abused. It doesn't get thinned much.

 

[Benuser]

Hope you can see what I mean in these pictures.

First knife. Kind of thick behind the edge. Look at the width of the shiny part along the cutting edge. Could use a thinning.View attachment 347952


This next one is quite thin behind the edge. The shiny part of the level is barely visible. Doesn't need thinning.View attachment 347953


Hope this gives you a good visual idea of when to thin.

Excellent, but won't work when the bevels have been convexed. In that case: check if the edge still is nail flexing — provided it was before.