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sharpening struggles

Tue Jan 29, 2013 7:08 am

i'm experiencing some issues with sharpening and have a few possible explanations, but was looking for some advice that could save time/money/stress.

i use a number of tojiros and really like them. my most frequent sharpening routine is to start with a 1000 grit stone. i divide my blade into sections doing equal passes/concentrate on spots that need it, hold an appropriate angle, and establish a solid burr. i do the same process on the other side, deburr on cork, and do heel to tip edge leading strokes to even the blade out on both sides. i then go up to a 6000 grit stone, establish a quick burr, flip/establish, deburr on cork, and do heel to tip edge leading strokes to even the blade, lightening in pressure as i go. i then go to a 10000 grit stone and do stropping motions, attempting to remove as much of the burr as possible that remains.

my issue is that after 6 months or so of sharpening with a new knife in this manner about once every week or so, doing that routine starts to not cut it (pun intended). i feel i need to and do go to a lower grit stone (300) first and follow the same burr formation as above on that, then do the same process as above following it. i find that as soon as i incorporate the 300 grit into the order with any knife i start experiencing some issues. the burr formation is good the whole way through and i feel like i get it off on the 10000 solid enough. i can cut paper, hair, etc but the results fade pretty quick when prepping in the kitchen, particularly downward motions, and becomes extremely dull to the point of not being able to use it (can still cut hair for some reason but not the onion). so my concerns/questions would be the following...

-300 grit to 1000 is too big of a jump (i've read in previous threads that this can leave a wire edge that never gets removed)
-i need to incorporate another stone between 1000 and 6000
-i need to incorporate stropping at the end because of the steel tojiro uses

i've tried thinning a bit on my knives because i thought after this period of time sharpening the shoulders were getting chunky and i'm not sure how far i should go with that in terms of creating a secondary bevel at 10 degrees and the primary bevel at 15 degrees, or if it should really just be a couple of strokes at 10 degrees to remove whatever shoulder has been exposed. i use a Borosilicate rod throughout the week but i find that it doesn't really do that much, and i know it's not the rods fault, so i'm not sure if there isn't an edge at all, the burr can't come off, or another reason.

looking to streamline the process to get the results i'm looking for without spending a lot of money on the trial and error process unnecessarily. anyone been in a similar situation and have some advice for how to fix it?

Re: sharpening struggles

Tue Jan 29, 2013 2:18 pm

What 300 grit stone are we talking about....in fact, can you please let us know what all the stones are? I don't know how much the others will matter, but knowing the 300 will gauge the jump between it and the 1,000 better.

However, I don't think it's likely to be too big of a jump.

Tojiro's are notorious for burr's. In fact, Taz will be along shortly to discuss this, so I'll leave it to him. :)

What you describe, though, certainly sounds like a residual burr.

I can't tell you if the knife needs thinned without seeing it. You could buy a pair of cheap calipers and let us know what you get, but even that is difficult to gauge since where you measure is critical to the analyzing the data.

So, again, it sounds like a burr. My suggestion would be to get a piece of felt from CKTG:

http://www.chefknivestogo.com/harohadefebl.html

or better yet:

http://www.chefknivestogo.com/rohafepad113.html

You can rig up something to hold that felt pad if you don't have a HA base.

Be aggressive with it, don't be shy. You have to remove that wire edge before your final stone or you're not sharpening the edge.

Another cheap option would be to buy a knife made from AEB-L which is much better in regards to burr forming and when one does form is easier to remove. If you don't have the problems with the AEB-L knife, then it's the knife you're having problems with.

Re: sharpening struggles

Tue Jan 29, 2013 2:54 pm

Thanks Adam! Fortunetly, I don't have to deal with VG-10 knives much, except when my buddies wife puts all of her Shuns in the Dishwasher and I gotta remove mega chips. LOL.

VG-10 can leave a nasty burr behind that holds on pretty hard. What you may be ending up doing is simply aligning the burr, not removing it fully. It will feel sharp and cut, but will roll over when cutting food. You need to remove the burr completely; felt blocks seem to work nice since they will catch the burr and rip it off, but it may take a while to get it all deburred fully. Even doing a micro bevel may not help if the burr isn't removed. VG-10 is used in a LOT of the entry level Japanese knives and it drives people nuts with the burr that can be a PITA to remove completely.

Can you get a picture of the choil area like I did in the "Puzzled" post?? That will give us an idea of how far back the edge has gone up the blade and how thick it is behind the edge. How far from the edge is the cladding line?

Re: sharpening struggles

Tue Jan 29, 2013 3:04 pm

The 300, 1000, and 6000 stones are shun combinations stones (bought them from a retail store before i found out about this website/knew of the array of options). i also just purchased the felt block from cktg recently and it's on it's way.

and ya i'm sure the blades could get thinned, but not excessively to be causing the problem. it just always seems like the burr never really wants to come off fully. once the knife dulls during the prep, it's easy to feel where the burr has flipped to one side pretty aggressively.

thanks for the feedback! i'll look into the other steel option for the time being perhaps. i have enough money invested in tojiros at this point to have to figure these guys out, but it'd be nice to have another steel type as well in case push comes to shove.

i'll try to get some pictures up soon, have to find a camera that'll get a good enough shot.

what would be the appropriate stages to deburr going through this (or any) stone progression? should i be waiting until just before the finishing stone/(future strop) to deburr and then go crazy? or should it be after each stone like i've been doing?

tim

Re: sharpening struggles

Tue Jan 29, 2013 3:22 pm

I deburr after every stone.

Re: sharpening struggles

Wed Jan 30, 2013 5:13 pm

Me too. It's easy to deburr so why not just run it through something between stones?

Or you can just use a couple light edge trailing strokes to abrade the burr if you prefer.

Re: sharpening struggles

Wed Jan 30, 2013 5:28 pm

I've heard it said by some that de-burring on low grit stones can be counter productive if the burr is too large and then removed, which could destroy the bevel alignment. Some have recommended only lightly abrading with edge trailing strokes on lower grit stones and then using felt, soft wood, etc to de-burr while moving through the finishing stones. Just another perspective that I have found helpful. Josh

Re: sharpening struggles

Wed Jan 30, 2013 5:49 pm

I actually wait to deburr until I am at the 5K. After each stone, I check to make sure that the burr has gotten smaller than the burr from the previous stone. I get kind of leary of pulling a burr off from a 1200 grit stone; wouldn't that leave a flat spot on the edge?

Re: sharpening struggles

Wed Jan 30, 2013 6:02 pm

Some posts I've read in the past suggest that pulling a low grit burr off the edge can leave a microscopic canyon between the 2 bevels so that they no longer touch. -Josh

Re: sharpening struggles

Wed Jan 30, 2013 6:43 pm

Yeah, I saw that with my loupe a few times; the bevels weren't meeting anymore ad there was a flat looking spot.
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