Chipping edge, Help!

uilleann

uilleann

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Nov 20, 2016
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I got a new knife and it has a 1095 blade with hamon. Does the hamon potentially make the steel brittle. I was putting a 17 degree edge on it (it was at 20) and it was talking a while with a 140 diamond stone. So I had "the beast" a 50 grid diamond stone. This is all on a KME sharpener. I also put some pressure on the stone. Then I started to notice this chippy toothing thing happening. I have never seen that before.

So any help please. What is best to do next? I also have a Make Sharp Ken onion sharpener with the blade grind attachment.

Thanks.
 
Regarding the line following your bevel, is that just illumination or is that a separate bevel that was not ground all the way down to the edge?

If that is two bevels, then continue to bring that lower angle up to the apex, and keep the pressure light when apexing.

I know some high alloyed steels don't respond that nicely to ceramic and other harder sharpening materials, and a waterstone works better.

You may be experiencing some chipping due to too much pressure, damaged HT, or other variables, but the HT wouldn't be likely if it was from a reputable knifemaker.
 
it was talking a while with a 140 diamond stone
Click to expand...

Heck with the chipping (you can sharpen that out (with some nice water stones)) . . .
I want to know what the blade said to the 140 stone.
 
uilleann said:
View attachment 686013

I got a new knife and it has a 1095 blade with hamon. Does the hamon potentially make the steel brittle. I was putting a 17 degree edge on it (it was at 20) and it was talking a while with a 140 diamond stone. So I had "the beast" a 50 grid diamond stone. This is all on a KME sharpener. I also put some pressure on the stone. Then I started to notice this chippy toothing thing happening. I have never seen that before.

So any help please. What is best to do next? I also have a Make Sharp Ken onion sharpener with the blade grind attachment.

Thanks.
Click to expand...
Hi,

First I would like to congratulate you on just trying stuff and putting equipment you own to use, it is good :)


Rule of thumb of "chipping" and sharpness/sharpening/edge problems,
Dont consider(blame) the heat treat (even hamon)
until you've ruled out the sharpening (esp factory sharpening)
so, this is a sharpening issue
50 grit IS GIGANTIC :) ok its only MACRO its 348 micron or 348/1000mm or 34.8% of 1 millimeter , its 3 times thicker than printer paper, where as the apex is ~1 micron (1/1000 of a mm or 0.1%)
if you apexed the edge or raised a burr with 50 grit,
esp with high force,

you should expect that the next few sharpenings to be less than perfect

what you're supposed to do with the extra coarse grits is not sharpen with them,
but change blade bevels (primary grinds) and stop long before you reach the edge
which is waaay before you reach the tip of the edge ie the apex

for apex work you need ultra light force, as much under 100 grams as you can go,
consider the gingerly light touch with sharp abrasives in these two videos
Knife sharpening : 36 grit dressing stone - Cliff Stamp
Extreme low grit sharpening : 24 grit nubatama - Cliff Stamp

Consider that under 15 dps edge can chop bones And 12 dps edge can still shaves/whittles beard hair after 1000 slices of hardwood ( yes a 1000 slices of hardwood )

so next I would jump to 140 grit or 200 to 400 grit and sharpen at 12-15 degrees until the scratches from the 50 grit aren't visible,

it might take a few sharpenings before the edge sharpens easily and stops chipping/rolling...

Keep at it
 
Patience, grasshopper.

140 Stone, let up on pressure, and take your time.
 
Do not use heavy pressure on any diamond hone - it will ruin it.

Carbon steel at higher Rockwell C hardness is a poor match for coarse diamonds, the above advice is spot on - drop back to the 140 and go light. I'd consider using a drop or two of mineral oil as well - it helps the chip break out with less distortion and could be of notable help on 1095 run to high hardness (an assumption on my part). Even then I'd expect this steel to chip a bit more than some stainless when sharpened with diamonds, at least until you get to a brighter finish.
 
50 grit diamond is way too coarse... even regular stones in this grit range are too coarse and almost always cause more damage than was already there. I've even experienced this with 140 grit diamond plates and ironically it was on carbon steel.
 
50 grit just rips the edge out, never apex with the 50grit im told. also heard if you are having chipping at a lower angle like 15 to make it more like 17 or even 20.
 
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