# Microchip (pic heavy)



## chiffonodd (Mar 8, 2015)

I started watching Murray Carter's sharpening videos, and he recommends beginning each sharpening session by thinning (not a complete thinning session, but just sharpening the blade flush against the stone for a couple minutes, which over time will result in thinning). He also recommends sharpening at as low of an angle as you think your knife can possibly take it.

Well I thinned a bit and went pretty low and was excited about what I thought was a terrific new sharpening achievement  the knife felt thinner and cut better than I had ever experienced. But then it promptly developed a couple microchips. It's a MAC gyuto which I thought would be soft enough not to chip, but I probably took it way too low and thin at the edge. I've owned this knife for about 6 months and never experienced any chipping before. 

Here are some different shots:

















Seeing it zoomed in, I'm embarrassed at how messy the edge is :O -- there are a few distinct bevels, showing that I'm not maintaining a consistent angle and obviously need to practice that. 

*Anyway: To clean this all up, do I need to just start over at 1K and create a new primary edge with a bit higher of an angle? Or is there a way to attempt to salvage this while maintaining a low angle?*

Please help :begging:

PS I've since put a microbevel on the right side of the blade (not pictured), which I hope will help maintain stability.


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## gic (Mar 9, 2015)

I'm a big believer in very fine microbevels whenever I get gung ho about bringing the angle down. Lift the knife angle up 3-5 degrees from the angle you sharpened at and takes a few strokes on your finest grit stone, helps a lot I have discovered...


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## WingKKF (Mar 9, 2015)

Now you know why carbon steel knives can perform better than stainless/semi stainless knives. It's the edge stability at acute angles. My $10 carbon steel Chinese cleaver does not microchip like my $100+ Carbonext.


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## ThEoRy (Mar 9, 2015)

That's kind of a blanket statement though. Too many variables for sure. I have carbon that chips and stainless that does not for example.


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## WingKKF (Mar 9, 2015)

Sure that's a general statement. A big variable in edge stability is the presence or absence of large chromium carbides.Outside of AEB-L heat treated by Devin Thomas, the probability of microchipping is lower in a correctly heat treated carbon steel knife vs a stainless knife at the same acute edge angle.


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## icanhaschzbrgr (Mar 9, 2015)

WingKKF said:


> Sure that's a general statement. A big variable in edge stability is the presence or absence of large chromium carbides.Outside of AEB-L heat treated by Devin Thomas, the probability of microchipping is lower in a correctly heat treated carbon steel knife vs a stainless knife at the same acute edge angle.



That's not just a general statement, that's a general delusion. There are a lot of makers who knows how to deal with stainless so that it would perform beautifully and doesn't chip.


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## WillC (Mar 9, 2015)

Tiny micro chips are much easier to get out on the stones than a distortion in the edge, or a chip with distortion at the edges with minimal removal of material. This is the reason ,(as well as best possible edge retention) to use steel at its limit of stability, blue 1 or white 1 for example at 65 hrc. So in this case the choice of steel and heat treatment is such that pushed to destruction it will chip, and chip small and cleanly with no distortion. 
But if your working around bones, on plastic chopping board or gritty food sometimes a tougher steel is going to be a more practical choice as well as adjustments to your geometry. Of course on harder carbon knives you can also adjust the size and angle of your microbevel to suit purpose and use.

Its always easier to fine tweak final edge geometry on a thin edge, so as a rule of thumb thin , add a tiny microbevel around twice the thinning angle, if you get small microchips, make the microbevel a little larger until you have the edge stability you need.

Stainless steels fit into all kinds of categories. Generally the ones which can become hard enough to give anything like the performance of a high hardness carbon blade will not be easy to sharpen.

Fine carbide stainless steels like, AEB-L, 13c, 14c28n I have used and tested extensively ...... they are very tough on a thin edge, meaning they can still show distortion at full hardness at around 62/63hrc so even though they take a super fine edge....you may find yourself increasing the size of the microbevel to avoid distortion conversely to chipping. But these stainlesses are nice to sharpen and with the advantage of being stainless. There are always compromises and your preference will depend on your use, sharpening routine etc etc..........


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## chiffonodd (Mar 9, 2015)

As for fixing this knife though, do I sharpen the chips out at the same low angle and see if putting a microbevel fixes things? Or do I sharpen them out at a higher angle, and make do with a tougher but more boring edge 

edit: posted before the above appeared whoops, thanks for the advice


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## WillC (Mar 9, 2015)

My routine is to stick with two angles. A low thinning angle, I do it by eye so hard to give an exact angle, lets say 6-8 degrees per side, then a microlevel twice this angle.
For a chip, I would work the microbevel until the chip disappears, the follow the thinning angle into the edge until your now too large microlevel all but disappears, and put the microbevel back with a few strokes at the end.

You will be surprised how quickly the chip disappears.......

For general maintenance I always follow the thinning angle on the stones, then put the microbevel back at the end. This works for me and keeps it all neat and easy to maintain, keep thin and make adjustments to the final microbevel size/angle.


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## chinacats (Mar 9, 2015)

Nothing boring about finding an edge that works for both you and your knife.


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## chiffonodd (Mar 9, 2015)

WillC said:


> My routine is to stick with two angles. A low thinning angle, I do it by eye so hard to give an exact angle, lets say 6-8 degrees per side, then a microlevel twice this angle.
> For a chip, I would work the microbevel until the chip disappears, the follow the thinning angle into the edge until your now too large microlevel all but disappears, and put the microbevel back with a few strokes at the end.
> 
> You will be surprised how quickly the chip disappears.......
> ...



So one variable here is that the chip is actually primarily on the left side of the knife, whereas I would be putting a microbevel on the right side. I know that has no bearing on this situation going forward, but would it change the sequence of how you would go about fixing the chip?

If I read your post correctly, you said you would sharpen the chip out basically by putting on a microbevel, and would then go back and thin out the primary edge behind the microbevel.

But here my microbevel is going to go on the right side. so does it make more sense to sharpen out the chip at a low angle on both sides, and then put the microbevel on the right side?


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## chiffonodd (Mar 9, 2015)

chinacats said:


> Nothing boring about finding an edge that works for both you and your knife.



100% correct. But after making vertical cuts in an onion with what felt like zero resistance I will be sad to go back.


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## WillC (Mar 9, 2015)

Yes I was generally assuming the process with equal symmetry , What you suggest would work out very well I think with the position of the chip


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## chiffonodd (Mar 9, 2015)

WillC said:


> Yes I was generally assuming the process with equal symmetry , What you suggest would work out very well I think with the position of the chip



Thanks I'll give it a shot and see what happens - sorry for omitting that detail before!


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