Losing my virginity

[henkle]

OK, so I've been practicing on some old Ikea and Chicago Cutlery knives using a Naniwa 1000/6000 combo stone, getting my instruction on sharpening primarily online (watching too many vids to recount). In the last couple of days, I worked my way through Murray Carters 2+ hour sharpening basics video and was intrigued by his secondary/primary edge sharpening technique. So I got out my practice knives again, this time along with a Zhen 3-layer VG-10 gyuto.

In the Carter video, it seemed as if he was putting the knife flat on the stone when he was "thinning" the secondary edge. He didn't really put any angle on the knife against the stone until he was sharpening the primary edge.

After doing what I understood as thinning and sharpening these knives (according to my interpretation of his instructions) I was able to slice a tomato's skin with the weight of the knife only (for the most part). However, due I'm sure to an unrefined technique, the blades showed a significant amount of surface that showed the removal of the material. A cosmetic issue not a functional one. Nevertheless, I soldiered on and took my new Kiya virgin carbon petty knife and decided to give it a go for the first time. First time sharpening a carbon steel knife. Wow, what a difference. I was able to get the same level of sharpness with very little effort (and without the cosmetic damage). So I need some feedback on a couple of things...

1. I know that stainless is supposed to be harder to sharpen than carbon, but is the scratching here just a matter of crappy technique?
2. I have a Wakui Tesshu White II Steel Nashiji gyuto on the way. It has a stainless cladding. Would the secondary edge of a knife like this be under the cladding hamon line or would part of the cladding be considered the secondary edge?

Any advice would be appreciated. Thanks,

Pics below post-sharpening. I think that my technique was pretty close to the same for each knife, but the post sharpening markings look completely different.

 

[ModRQC]

Carter himself says to use about 5* angle to thin as a norm, but to mostly watch your progress. Thinning flat on the stone does nothing to your edge bevel/primary bevel, it thins the face.

It may show less on your carbon because it's not a polished finish like your SS. However I can easily see marks where you still got a bit high up the blade there too. Much less abused though, so one of two things: you did use a bit more angle with the carbon, almost a correct one; or you were "flat" on the wide bevel of the knife causing some damage there but not to the faces themselves.

The rookie tip here for thinning is to color the part of the blade you want to thin with a sharpie, and closely monitor your first strokes until you catch on the necessary angle you need to use by how you abraded ink away.

Don't worry and keep practicing with the cheaper SS knives until you get to minimize the damage ratio vs. doing the actual abrading that needs to be done. Don't fret about cosmetics so much yet, but sure do try to minimize damage, which means, becoming more precise. However, you also need to bring more focus to the part that does need thinning. In your SS pic, last of the post, I can see that tip and sections towards the heel weren't thinned very much, while other places seem ok for a first try.

 

[ModRQC]

Another advantage of the sharpie trick is that it forces you to stop and really consider: what it is you want to thin?

Because a big problem with many people around here advising that all knives need thinning is that rookies don't really understand what and why they need to thin when it comes to their one SPECIFIC knife. Each knife requires a certain amount of work, based on itself, not general consensus of something that needs to be done most of the time, but not the same way nor the same amount in each case.

Once you'll stop to take the time to consider "until where do I color up the blade", you'll reexamine your blade, feel for the primary bevel, and determine by yourself what kind of work is involved. Your assessment may not be right. But it will get finer and finer and surer as you practice - you should rely on your experience with the knife to know that it needs thinning, and in what measure.

 

[ian]

Scratches don’t care if your steel is stainless or carbon. Probably you scratched up the face of the knife on the stainless blade because the grind is fairly flat all the way up the knife. The carbon knife probably has some convexity near the edge, so that when you put it flat on the stone at the edge, the rest of the knife doesn’t contact.

 

[ian]

For question 2, you mean the lamination line, not the hamon line. Probably there’s also convexity near the edge on the Wakui. Stressing about not hitting the stainless cladding is kinda beside the point, though. If the knife is flat on the stone, you will scratch the part of it that contacts the stone. That’s a stone’s whole purpose: to scratch.

 

[henkle]

Thanks for the good advice. Very helpful.

 

[henkle]

OK, so I just watched chapter 2 of the Murray/Stanley sharpening method and Murray scratched up his knife just like I did while thinning the knife. On my stainless knives, in the polishing phase, I lost my nice matte finish and the surface became smooth. Granted, he was doing an expedient method and didn't return the knife to its original cosmetic state (in another Q&A video he says that when thinning the secondary edge scratches are inevitable), but I'm wondering is it possible, necessary, or desirable, to get the matte finish back to make the knife look like it did before I sharpened it? (I realize desirable and necessary are subjective terms). If it is possible is sandpaper the only alternative?

 

[ModRQC]

It can be important to polish scratches made with a lower grit stone especially since the rough surface it may leave may hinder the knife from gliding through food as well as before. Will be felt more on a polished ss knife than on a clad knife but could affect both.

 

[ModRQC]

You can use a higher grit stone to try and polish scratches from the lower grit but it’s harder to just do it effectively. Sandpaper works well to bring back a simili mirror finish on SS but will continue to abrade the cladding of your Other knife further.

 

[ModRQC]

I use automotive sandpaper - a progression of 400-800-1000-2000 cause it’s what I have under hand. Brings back enough polish to look a lot nicer and most important as smooth as originally.

See a Victorinox here...

 

[henkle]

Cool

 

[amithrain]

Yeah, you can absolutely get the matte finish back. In the third episode,
of the Carter-Stanley method, you see Hap Stanley polish the secondary edge back to the matte finish.