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Deburr Issue?

Sat Mar 29, 2014 9:57 pm

Hi everyone, I am another new guy with a question about this Watanabe 150mm petty I've had for a couple months.
I cannot get this thing to hold an edge to save my life. I took a picture with lots of glare to try to show what's happening. I can get it pretty sharp, but the edge just buckles even after one light use (maybe you can see the deformation along the edge in the pic). This is from cutting up two tomatoes and a cucumber after a sharpening...

About me and my skills: I am a professional carpenter/woodworker with lots of experience sharpening blue/white steel Jp tools. I have a pretty decent selection of stones and feel like I know them pretty well. Knives aren't totally new to me, but I've probably only been sharpening for 2-3 years. I get good results that last on my other knives (a Yoshikane 180 Gyuto and two kind of generic wa-handled knives from Japan Woodworker http://www.japanwoodworker.com/product/ ... agata.aspx) so I'm a little curious about the fact that I'm having such issues with just this one. It seriously looks like I've used it to chop sand on a granite counter, which I have not.

Also... although I'm pretty sure this is a burr/wire edge issue, I also can't say I've been totally impressed by this knife overall. The fit and finish was kind of rough, the grind was pretty bad (see pic--it took me like 2 hours to flatten out the high/low spots enough to sharpen) and I had to pay extra to upgrade from a plastic ferrule, which brought the price up to around $200. I feel like maybe I could have done better.

OK, I'll try to wrap it up. I have tried EVERYTHING to deburr this blade after sharpening: edge trailing strokes on each stone, stropping, gentle slicing through cork, soft wood, felt block, you name it. Any suggestions?

Also, if anyone has any suggestions for a nice laser-ish petty, I'm looking. I keep looking at the Kamo R2 http://www.chefknivestogo.com/kar2pe15.html. It just looks bad. But I'd love to hear from someone who's actually used one and has some feedback.

Any help you guys can offer is greatly appreciated.


Re: Deburr Issue?

Sat Mar 29, 2014 11:11 pm

Hi & welcome to the forum.

Make sure that your de-burring stropping strokes are SUPER LIGHT & alternate blade side after each stroke.

Very lightly pull the edge through the wooden block after stropping each side.

Continue with this until just the weight of the knife is used to strop, as well as de-burr.

Also be mindful of rounding the edge during stropping.


Re: Deburr Issue?

Sun Mar 30, 2014 1:01 am

Im not familiar with this knife, but the first thing that came to my mind was maybe try an angle that isn't as steep for the bevel and then give it a micro bevel afterwards.

Re: Deburr Issue?

Sun Mar 30, 2014 6:02 am

+1 to what others have said.

It looks from the picture, and I could be wrong, but it looks like you have a major wire going on. If that is the case then what you describe is the result you will get with having a wire. In my limited experience I think you are being too gentle when removing the burr or wire. I don't know if you are using any magnification but if you are you should be able to see it, if you are not you should be.

I think you need to start from the beginning on a low grit stone making sure you are flipping the burr from side to side. The burr will become smaller and smaller as you go. Starting over will remove any fatigued metal and allow you to get to some fresh metal. I use the stone I'm using to de-burr the blade. Don't be afraid to use some pressure to remove the burr. Don't jump to the next stone until you have a small continuous even burr that can easily be removed with a couple of strokes on the edge of the stone.

When you go to the next stone the burr should be smaller and the strokes needed and pressure needed become less and less. By the time you reach your finishing stone you should barely have any burr at all. Light edge trailing strokes should be the finishing touch on the last stone or strop. But don't over do it. 2 to 5 strokes is all you need.

From what I understand some metals have a tendancy to create a wire edge more than others and you must be careful to remove it before moving on to the next stone. I think most beginners make the mistake of not spending enough time on the course stones and not looking at the edge under magnification. I use a cheap headstrap magnifier I got from harborfreight. It works great.

I think once you get the technique down better you won't need to be looking at another knife. You will love the one you have.

Hope this helps.


Re: Deburr Issue?

Sun Mar 30, 2014 9:00 am

That's a VERY large burr! Drag the edge through wood and use light strokes on your fine stone.

Are you grinding to a zero bevel? If so add a secondary bevel.

Re: Deburr Issue?

Sun Mar 30, 2014 12:51 pm

Wow, thanks to everyone for all the input. So here's what I've got so far:

1. It is definitely a burr or wire edge
2. I might be doing the right things when sharpening, just not doing those things correctly
3. Use a micro bevel/steeper angle

The knife does have a micro bevel, probably around 10-12°. Would a higher angle produce less of a burr? Seems like it might.

Also I want to make sure I understand the term "stropping". Is that used to describe edge-trailing strokes whether on the stone, or a leather or other strop with compound? I'm using a piece of pine or fir, planed super smooth and flat and loaded with Green Rouge to strop, but I do also end with edge-trailing strokes on each stone. Should I be going with one or the other? So if I'm going to use the stone to remove the burr, should I stay away from the strop/compound at the end? Or would a leather strop be better?

Thanks again for all the advice.

Re: Deburr Issue?

Sun Mar 30, 2014 1:22 pm

Birchply makes a good deburring wood. But also you could spend a little time stropping the burr off. Try holding the knife with your thumb and index finger as lightly as possible then use the middle finger to stabalize the blade. Make consistent sweeping motions back and forth with as little pressure as possible. The stone does the work and you don't suffer big burrs as much. Just be sure to flip it over consistently.

Try not to bobble the blade too much...Some up and down play is going to happen in free hand sharpening, the goal is to keep everything at a minimum.

Re: Deburr Issue?

Sun Mar 30, 2014 9:10 pm

You sir have a burr.

Finish off with some light edge leading strokes on your last couple stones , this nearly always prevent burr formation at the final steps.

Im not a fan of breaking off a burr , but if you do drag it through a material to break off the burr , go back and do some light edge leading strokes to finish off.
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