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Re: Push cutting paper

Fri Dec 06, 2013 8:55 pm

With the felt cube and cork you are essentially ripping the burr off, leaving a small flat or rough area at the edge of the blade wherever the burr was attached. Even after removing a burr in that fashion you will need to either use a fine stone (or almost any stone can do it really but the coarser you go the rougher the edge) with light, light pressure like Jackknifeh talks about above or a strop of some kind to polish the little flats/rough areas into a solid point where both edge planes meet. The goal in the final finishing stages is not to remove metal in the true sense of sharpening but to refine, smooth out, and clean up the new edge you ground into being by way of polishing.

Re: Push cutting paper

Fri Dec 06, 2013 9:24 pm

Chrismit29 wrote:Thanks for all the insight guys. It makes me feel better that it doesn't sound like I'm doing anything too far off base. As far as deburring goes I currently use a felt cube and cork. I feel like I'm getting it all bit any suggestions on other methods for deburring?

I got a felt strop block a couple of years ago. It would be the last step in sharpening when I used it. After using it the edge seemed sharper. So that is good. I didn't like that I didn't know why it got sharper. As time went on and I learned more about edges it occurred to me that maybe the little tiny burrs the block was removing were actually being broken (snapped) off the edge. If this was the case I didn't like the possibility that there were areas on my edge that didn't look like two smooth bevels meeting at the edge apex. Rather there would be places that looked more jagged. I'm not thinking of a toothy or coarse edge you get after using a coarser stone. I'll admit this "thought" was just that. I have no testing or magnified pictures to back it up. But since I had doubt I quit using the felt block. Now I believe the best method to remove all burrs is how I described in the other post. Just remove the burrs on the last stone you use so the edge is very very sharp and a very usable. Then strops can be used to refine or smooth the edge even further. I don't consider a strop a tool to remove burrs. I think all burrs should be removed before stropping. I would like to hear other people's thoughts about the deburring block. I did like it enough that I bought a second one on the next order I placed. It all boils down to I don't believe a burr should ever be broken or snapped off the edge. It should never be folded back straight and it should never be flipped to the other side that can happen when using very soft strops and using too much pressure. The burr should be removed by abrading it from the top of the burr down until the bevel is smooth right up to the edge apex.

My literal goal regarding burrs is to NEVER form a burr to begine with. The "goal" is to sharpen both sides until they meet. Not stroke one side until a burr is formed on the opposite side then removing it. As I sharpen I keep testing the sharpness with phone book paper. When the bevels meet the edge will cut the paper better and better until the edge is refined enough. Then I'll finish using whatever stone or strop I want. Let me clarify my "GOAL" is to never form a burr. To never form any burr at all is just about not possible IMO. My Dad always said this about my grades. He said "if want to get a B, you better try hard to get an A". So, I try hard to get NO BURR but live with the fact that I will create burrs but hopefully they are very small. I hope this makes at least a little sense. OTOH, I always appreciate it when others explain more to me or even tell me when my thinking is way off base. Anyway, this is where I'm at in the "search for the perfect edge" at the moment.


Re: Push cutting paper

Sat Dec 07, 2013 3:24 am

I read somewhere that drawing through cork/felt wasn't enough to totally remove the burr and that afterwards you should lightly strop on the stone a time or two. I don't know how true this is but it seems to have improved my edges.

Re: Push cutting paper

Sat Dec 07, 2013 10:33 am

Any suggestions on alternate deburring methods?

Re: Push cutting paper

Sat Dec 07, 2013 2:12 pm

Chrismit29 wrote:Any suggestions on alternate deburring methods?

A common method of dealing with a burr is to "straighten" the edge. I think that is what it's called when you use a steel and trailing strokes. I believe the theory is if there is a burr or a place where the edge has folded over in one direction this will straighten it back out. When you bend a thin piece of metal back and forth until it seperates what you have done is weaken the steel until you can seqerate it. Picture bending a coke can back and forth until it tear apart. A "straightened" edge is weak and will dull very fast. Not understanding this can lead us to think the blade steel doesn't have good edge retention. So straightening a burr is one method but I don't think it's the best method.

I believe the only way we should remove burrs is to grind them down by using very light pressure so you don't bend it back and forth. Using really light strokes at the correct angle with good quality abrasive stones is the only way I know of to do the best job. The last stone in your progression should be the one to really try to remove all hints of a burr. You can remove any burr using the stone you are on before changing to the next grit but I don't really worry about it until the very last stone. There shouldn't be any BIG burrs anyway. Keep them small by not stroking 10 times on one side then 10 strokes on the other. I like to flip the blade after each stroke but I sometimes go aheat and do 2 or 3 on one side them flip it over. It's like everybody KNOWS you should chalk your cue before every shot but sometimes we get lazy and don't. :) Trying to speed up and take shortcuts can often end with us having to do more work in the long run anyway. I like the saying "if you don't have time to do it right the first time your sure don't have time to do it twice". :)

The truth is IMO that even though burrs are horrible for cutting performance they really aren't hard to remove. Just use very VERY light push strokes. Trailing strokes are ok as long as you are SURE to use very light pressure. If you have a burr just do one very light srtoke on that side and I bet the burr is gone. Two or three strokes may form a burr on the other side. Burrs are weakened steel and stones remove them fast.

Re: Push cutting paper

Sat Dec 07, 2013 10:30 pm

I'm still with Jackknifeh on this. The only good way (and this is just my opinion! lol There are many others!) to remove a burr is some sort of polishing action.

And yes, a knife steel (not ceramic, diamond, etc. but a TRUE non-abrasive steel) can straighten a burr somewhat, but its intended purpose is to straighten a good clean edge without a burr. Softer steels can acquire edge deformations during use, and a steel only serves to bring the edge back to true again. If you have to steel a knife every time you use it in a home kitchen, you're probably just straightening the burr and NOT the actual edge. That or you have a horrendous steel. lol

All that being said, even Murray Carter will run his edges on wood to remove a burr while sharpening so you are not wrong to use a felt block, but if you watch his sharpening vids he also goes through the polishing and refining steps on the stones and then newspaper to get face shaving edges on his knives. There are almost as many ways to sharpen knives as there are people that sharpen knives, but with the good ones there seems to always be a final edge refinement (polishing to some degree) that happens which really brings out the edge, mid sharpening burr removal or not. It is just how they do it that differs.

Re: Push cutting paper

Sun Dec 08, 2013 6:18 pm

Yea two mentioned points worth reemphasizing

Dragging an edge on paper towels to detect burr. This should be more widely done but it just hasn't caught on as much as it should.

Using LIGHT pressure. It makes more sense to abrade the burr in place rather than flipping it over and over until it gets work hardened until it fractures off, leaving a work hardened 'knarly' area that doesn't even truly form an edge. It gives the sensation of sharpness but it is actually a jagged tearing rough area. I tend to do lateral sweeps with a light touch so you are abrading the burr in place. Lighter pressure also tends to produce smaller burrs so IMO it gives you more control of burr formation rather than generating hugh unnecessary burrs. I don't find edge leading or trailing critical.

Jack's point about relying on a straightened out burr is another often under-rated point. I would much rather have a finely abraded stone used to remove this weakened metal than using a steel (even a smooth one) for this reason, unless you are in a situation where you can't do it any other way (butcher, working in Ramsay's kitchen :) , etc)

Finally Jeff's point about magnification is extremely useful. Add a sharpie to it run along the edge and view it with some magnification - even 10x and you will progress much faster. "What one knows, one sees" is a quote I think of often. Learn to recognize burr and observe scratch patterns.


Re: Push cutting paper

Thu Dec 12, 2013 8:49 am

Thanks for all the advice. I practiced last night with my Mac Pro. Used the 5k rika and am now able to push cut on some parts of he blade. Other sections (primary the upsweep to the tip) aren't there yet. I don't think I have a burr, I was testing it by drawing through paper and I was able to feel some residual burr. Pretty sure I got it all now. Should I just continue to work on the section not push cutting with the 5k?

Re: Push cutting paper

Thu Dec 12, 2013 9:13 am

Chrismit29 wrote:Thanks for all the advice. I practiced last night with my Mac Pro. Used the 5k rika and am now able to push cut on some parts of he blade. Other sections (primary the upsweep to the tip) aren't there yet. I don't think I have a burr, I was testing it by drawing through paper and I was able to feel some residual burr. Pretty sure I got it all now. Should I just continue to work on the section not push cutting with the 5k?

I think your question could be divided into two questions. 1. Should I ONLY work on the sections not push cutting? 2. Should I continue with the 5k? To question 1, Yes, work only on the areas that need work. Knowing exactly where the area is I make sure I "overlap" this area and just outside this area just a bit so the edge bevels "blend". Hope that makes sense. To question 2, the stone you use would depend on the condition of the edge. Probably the 5k (or whichever stone you are using) would be the one to continue with. But, if you think the area needing more work is dull enough you may want to back up to the next coarser grit you have. This is a matter of getting used to the edge you are working on and how each stone performs on that level of sharpness/dullness. When I am deciding to use stone "A" (coarser) or stone "B" (finer) I always go with the finer grit first. This way I won't remove more steel than necessary too fast. If I find the finer grit is not effective enough then I change to the coarser grit. This is a general "policy" I go by but in your situation continuing with the 5k is probably perfect.

Hope this helps.


Re: Push cutting paper

Thu Dec 12, 2013 11:06 pm

More importantly...does it really push cut paper? Deburring can also be achieved with proper free hand stone techniques. I'm not expert on the subject but have been learning as I go.

A good paper push cut can be done with a really toothy edge or with a very finely polished edge. The important thing is to pay attention to how it grabs the paper. A nice toothy edge will have more bite to it and you'll feel some drag. If one particular spot of the knife seems buttery yet another spot seems more challenging to glide through the paper then you haven't got the bur out of the way.

Don't feel bad you can spend a long time chasing the burr. At some point in literally seconds the edge can be obtained as good as it gets...I mean you go from tearing to gliding in seconds...Then if you try to make it "better" it's also possible to entirely negate all the hard work you have done.

Bur chasing can be tedious. Ideally you want to be able to use only the weight of the blade and the slightest amount of pressure. Pay very close attention to the sound of the blade slicing into the paper. Do you hear tearing? That's fine...does the tearing sound become more airy as you continue to sharpen?

At some point it's going to feel good and not get any better. Push cutting paper is good but using an entire roll of paper towel is better. Push cut into the roll...Does it grab? If it does you've got bur. You an also crumple up a single piece of towel. But I think slicing the hell out of a single roll is a good exercise in learning how to chase those damn burrs out.

The Kono Gyuto has a thinner blade so it will naturally tear things up better. I think Shun knives are sharpened to overly steep angles. A little bevel on my shun classic has made it have a more predictable and lasting edge.

Good luck have fun and don't let the burr get the best of you. Believe it or not you can strop on cardboard or newspaper and get okay results.
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