I am trying to sharpen a yanagiba, profile question

[GeneH]

Do these single sided bevels get a single flat grind to the edge or it 2 bevels?

I got this one for 25 cents, new with a heavy rough 45 deg primary bevel and have been grinding it thinner. Don't know what they make $30 knives from but it sure is wear resistant.

On the back by behind the tip you can see that I cannot reach the edge. The rest of the back seems to have a ok hollow grind. But what do I know.

Ya it's a $30 knife I know. My expectations of this thing: none. I hope to get a feel of what a single bevel knife feels like, because I really really want to like it and get a sub $ 200 single bevel slicer eventually. Even worse than this deal though is that it's right-handed and I am left-handed.

Pictures I posted shortly. Can't post them from the KK F iPhone app.

 

[Keith Sinclair]

It has a hollow ground backside. A single bevel not two. The back looks like it has been little over worked.

 

[GeneH]

Thank you. I'll keep working the bevel down when i sharpen it.

Once the backside is overworked it can't be right back can it. How do professionals that use their knives all the time keep from overworking the backside with all the sharpenings through the life of that knife?

The backside is pretty much how the knife was originally, except near the tip. That was pretty flat already. The rest of the backside, if I remember right, I only used a 1K stone. Maybe I took off more than I realized. I will only use a 4K Stone and touch it enough to remove any burrs and clean the edge from now on.

Thanks for letting me know. Will get the mistakes out-of-the-way now.

 

[osakajoe]

Don't sharpen the back. Only break the bur off once the main side is sharpened

 

[Keith Sinclair]

Yes I remove the burr on SB with a light edge leading stroke. Backside totally flat to the stone.

 

[fujiyama]

How do professionals that use their knives all the time keep from overworking the backside with all the sharpenings through the life of that knife?

Essentially, they don't!

These are the stages of a yanagiba when very heavily used by professional sushi chef. The knife on the far right is only 3 years old!

Okay.. extreme example. I'd be surprised if any of us have that much use of a yanagiba in our lifetime.

You'll be fine if you lay the kireha (primary bevel) flat and sharpen. It will take time to even it out. Watch a few youtube videos from proper sources. Like suggested, only sharpen the back side to remove the burr (in this case to save steel). When sharpening the ura (back side), always hold the knife horizontal to the stone (not on a bias).

 

[GeneH]

Nice example of knives getting used so much. Thank you for that.

Got it about the back side, taking it easy now.

Wow, this is just awful steel; I just can't seem to grind it down. Or is flattening that long of a bevel always so time consuming?

I have never seen burrs so long and hard to get rid of. I put 3 more hours today trying to get the bevel flat to the edge. Used a 1800 RPM, 6 in flat glass and 60 grit and dunking to keep it cool. It's always going to have a slight primary bevel or slightly convex. Not worth my time on a $30 knife. Not taking it to the belt sander because I just don't have that good of control.

Question: Since I'm not doing raw fish, or anything fancy, what's preferable, vague convex, or long shallow primary bevel?

Oh, and lesson learned: if I ever do a nasty chip on a good knife, it goes off to someone associated with KKF to fix. I have to re-shape 1/2 inch of tip as I overground and have a birds beak kinda shape.

 

[GeneH]

Oh, and I did check out videos an googled yanagiba profiles... but always turn to this forum to get clear concise and accurate information.

Just sayin ... you know who I trust

 

[zitangy]

The flat side...

my opinion is that only the tip area is flat and i wld attempt to put some concavity on it by
abrading in on a sandpaper on sandpaper mounted on the curve side as opposed to the flat side which is mounted on a vice or the alternative way is to the "device" to the edge i.e. putting it flat on table and rubbing device on blade. You need to select which portion on the "hump" to use to get the concavity you desire. Color/ marker pen it so that you can see where you are removing steel.

Tip: do not go below 600 grit sandpaper do it slowly over a period of time till you get only the spine and edge shiny when you flat grind it on stone when normal sharpening.

have fun and rgds..d