Chipped my Toyama - help needed with repair

Hi all!

So, it seems I managed to chip my Toyama 150mm petty in its first few weeks of use... I have actually no ideia how I did this, only noticed because the tip was having a hard time making horizontal cuts into an onion. You can see in the pic below that there are two small chips near the tip.

https://drive.google.com/open?id=0B8whNyGUZqBJa2hoc1NfMFRmbEE

I'm not an expert sharpener by any means. Actually just got my first stones and started practicing. So I have some doubts on repairing this:

1- first, assuming I didn't drop this knife or banged it, what could have caused this? I don't do anything stupid to my knifes (use a hinoki board and make sure to stay away from bones, frozen food, etc). I never sharpened the Toyama, just started using it OOTB. Could it be the "factory" edge?

2- second, how exactly do I repair this, and what grit should I use? Should I sharpen as usual, until the chips are gone? I have a Gesshin 2000, a JNS 6000 and a diamond plate from JKI (bought it to flatten stones). Should I get a coarse stone, or can I use the Gesshin? Would the diamond plate be overkill?

Thanks in advance!

Just sharpen as usual and they will be gone in a session or two...

As to how it happened no idea... might just be some fatigued steel still at the edge... or hit something harder whole cutting, bumped a bone maybe... who knows

If you want to keep the blade profile as it is you could just sharpen like you usually do until the chips are gone. Or you could maintain the blades profile, but lose some thinness at the edge and sharpen at like a 40-50 degree angle until the chips are sharpened out using a low grit stone (this is an easy fix but you would need to do some thinning afterwards).
It really doesn't look to bad, just do what you normally do and it will be gone soon enough.

Just take it to the stones, those microchips will come out easily.

Thank's guys! Will sharpen as usual and see what happens.

As others have said. Just give it a fresh edge and those little chips will you be completely gone in 1 or 2 sessions.

Not uncommon with brand new knives, I'm afraid. Take a medium-coarse stone, start well behind the edge and don't be afraid to abrade a bit of steel.

a. to remove to the chips.. i normally scrape the edge spine leading on a 400 grit stone say at 60 degrees .... from tip to heel ( to maintain the geometry) till almost the top of the biggest chip line. from time to time, i may lower the angle to thin it and then increase the angle to work on the very edge. Pressure will determine the rate of steel removal

b. Your diamond plate... depends on the grit... a 1000 grit will just take longer time.

c. if you dont have a rough stone.. you can use sandpaper (400 or 600 grit )cheaper option.. secure it with glue or clamp and apply the method abov

hv fun..Z

it's really quick done!: diamond plate, 2000, 6000 and in 2 minutes your knife is like new.
Once I sent a knife to a guy and the tip broke during the shipping so I made a video to show him how to re shape the blade. (it's not the same damage and the result is not clean but you can take some inspiration)
[video=youtube;hgQ7F_Nm_h0]https://www.youtube.com/watch?v=hgQ7F_Nm_h0[/video]
BTW if you don't use this knife to slice crazy things like fresh raspberries or basil little cubes, try to put a micro bevel on it or you' gonna chip the knife every week.

nutmeg said:

it's really quick done!: diamond plate, 2000, 6000 and in 2 minutes your knife is like new.
Once I sent a knife to a guy and the tip broke during the shipping so I made a video to show him how to re shape the blade. (it's not the same damage and the result is not clean but you can take some inspiration)
[video=youtube;hgQ7F_Nm_h0]https://www.youtube.com/watch?v=hgQ7F_Nm_h0[/video]
BTW if you don't use this knife to slice crazy things like fresh raspberries or basil little cubes, try to put a micro bevel on it or you' gonna chip the knife every week.

Click to expand...

Probably sound advice... though i think the diamond plate you have from JKI is really only meant for flattening stones.

The one on the video is AI#Diamond with #170 grit. The important thing here was to have a rough surface to do the job quickly.

No one has said it yet, put on a microbevel after you sharpen this time.

Many thank's guys, lots of helpful advice.

My JKI diamond plate is 150 grit. It is sold specifically as a flattening plate, but I will email Jon and see if he thinks it could be used for minor knife repair. Otherwise, I will just start on the G2000 and, if that's taking too long, get a coarse stone (will need one someday anyway).

Microbevel is a sound idea also. I was quite careful with this knife and it still chipped, the edge is probably too fragile...

Choppin said:

Many thank's guys, lots of helpful advice.

My JKI diamond plate is 150 grit. It is sold specifically as a flattening plate, but I will email Jon and see if he thinks it could be used for minor knife repair. Otherwise, I will just start on the G2000 and, if that's taking too long, get a coarse stone (will need one someday anyway).

Microbevel is a sound idea also. I was quite careful with this knife and it still chipped, the edge is probably too fragile...

Click to expand...

I would not use it for knife repair... it will impact the life of the plate in a noticeable way

Thank's Jon. I will try to work it on the G2000 stone and if it's taking too long I might get a coarse stone

JBroida said:

I would not use it for knife repair... it will impact the life of the plate in a noticeable way

Click to expand...

Get a 400-500, both for sharpening out the chips and for the -- very minor -- tip correction from the spine. Very little work.

I don't think a Toyama's geometry benefits noticeably from a microbevel. I did have it "breadknife" on me once where I'd been testing jnat finishers a lot without ever resetting the edge. I took it to a king Hyper and it chipped out all along the edge. Good as gold after a trip to a 400 and back up again.

Benuser said:

Get a 400-500, both for sharpening out the chips and for the -- very minor -- tip correction from the spine. Very little work.

Click to expand...

I agree with Benuser. A 400 grit stone will take those chips out in a couple of minutes work. No big deal. Finish the edge on what ever stones you normally use after that.

Noodle Soup said:

A 400 grit stone will take those chips out in a couple of minutes work.

Click to expand...

a couple of strokes ;-)

You are probably right Nutmeg but it wasn't me doing the repair work so I don't have any idea how aggressive he would be on the stone.

Thank's again. I decided to get a Gesshin 400 to work on this. Will post the results later.

Just to give you an update - and thank you all for the help - I started on the Gesshin 2000 and quickly got rid of the chips. Didn't need to go lower in grit. Fast cutting stone with good finish!

Great it all worked out. But if you have a coarser stone, better start with that one. I've seen a few repairs with medium-fine stones that eventually seemed to leave an unnecessary weakness.

@Benuser- FWIW, the Gesshin 2000 cuts as quickly as many of the ceramic binder 1000 grit stones on steroids. Not at all similar to the Chosera 2000 in that respect

Even the Chosera 2k is quite aggressive, but thanks for the extra information!

I’m bringing this thread to life again as i have a similar problem.
Bought a 240 gyotu from JNS and was just amazed by its performance.
But then i accidentally dropped it off the counter and made a 1-2 mm Chip.
I removed the chip and thinned the knife but i just don’t get the same amazing performance. I think i thinned down to zero edge again.

So the question, is there something special about the original grind? Like slightly concave? How can i best reproduce the performance?

Thanks
Flo

flow_the_pro said:

I’m bringing this thread to life again as i have a similar problem.
Bought a 240 gyotu from JNS and was just amazed by its performance.
But then i accidentally dropped it off the counter and made a 1-2 mm Chip.
I removed the chip and thinned the knife but i just don’t get the same amazing performance. I think i thinned down to zero edge again.

So the question, is there something special about the original grind? Like slightly concave? How can i best reproduce the performance?

Thanks
Flo

Click to expand...

The problem with the ootb zero edge is it is very fragile. You get that crazy performance but the drawback is the edge can get micro chips even from just board contact. I went through this learning curve with my Watanabe which is essentially the same knife.

https://www.kitchenknifeforums.com/threads/durability-testing-watanabe-pro-gyuto.41263/

flow_the_pro said:

I’m bringing this thread to life again as i have a similar problem.
Bought a 240 gyotu from JNS and was just amazed by its performance.
But then i accidentally dropped it off the counter and made a 1-2 mm Chip.
I removed the chip and thinned the knife but i just don’t get the same amazing performance. I think i thinned down to zero edge again.

So the question, is there something special about the original grind? Like slightly concave? How can i best reproduce the performance?

Thanks
Flo

Click to expand...

I would thin it down just bte as much as you can / as much as the steel will take. Then lightly sharpen a high-ish angle (20 to 25 degs) edge onto it using a hard and fast mid grit stone; Shaptons, Washitas, Coticules, or similar. The faster the stone is, the higher the ‘grit’ can be.

TBH this is basically how I usually sharpen any good quality knife, cos it’s pretty foolproof way to maximise performance whilst retaining durability. The only slight difficulty is deburring properly well.

flow_the_pro said:

I’m bringing this thread to life again as i have a similar problem.
Bought a 240 gyotu from JNS and was just amazed by its performance.
But then i accidentally dropped it off the counter and made a 1-2 mm Chip.
I removed the chip and thinned the knife but i just don’t get the same amazing performance. I think i thinned down to zero edge again.

So the question, is there something special about the original grind? Like slightly concave? How can i best reproduce the performance?

Thanks
Flo

Click to expand...

I would be very surprised if JNS sent out a knife with a zero edge. If there's a difference in performance, my guess is the thinning has been stopped to early. You wouldn't be the first to underestimate the amount of steel to be removed. If you can't measure, the width of a bevel give an indication.

Tbh honest I remember Watanabes have that very low angle edge. Toyamas not so much, just normal edge angle.