advice from knife sharpening experts

so the title should read knife repair experts really!

I have a few knives that are about as sharp as a plastic ruler - edges are damaged and yes they frequent the dishwasher everytime they need a wash
I have a mix of Swibo and Global with stuffed edges

What is the best way to repair them DYI? assume it would be with wet stones but I do have a bench grinder :-)

Image Upload: 

piston broke's picture

Posts: 776

Date Joined: 05/11/08

No bench grinder

Tue, 2017-05-30 17:01

 The heat will ruin them. That's a start 

Posts: 195

Date Joined: 22/08/11

 hey mate,i am by no means an

Tue, 2017-05-30 17:02

 hey mate,

i am by no means an expert but i do pride my self on having sharp knives.

never put a knife on a grinder, the heat that it produces will influence the steel and it will reduce the quality overall

the best way to remove those dents would be to spend some time on a fairly course stone, something below 1000 grit will get the job done faster.

i prefer using diamond stones but any stone will work for.

after the course stone put it on a less course stone (2000 grit) and continue. by the end of it make sure there is no bevel on one side, if you have a piece of raw leather make sure you run your blade on it at the end, it will give a nice polish effect and finish off the sharpening process. 

By the looks of it there will be a fair bit of metal that you going to have to remove so a bit of time will be required.



Posts: 808

Date Joined: 22/07/10

 Guess what ruined them in

Tue, 2017-05-30 17:26

 Guess what ruined them in the first place,yes the dishwasher.mightvpay to get them back to a sharp edge by a professional.them continue the effort by hand on a wetstone.

chris raff's picture

Posts: 3257

Date Joined: 09/02/10

 No expert but with that

Tue, 2017-05-30 17:27

 No expert but with that notch on the swibo , I’d be tempted to grind it initially you’d be there awhile trying rub that out on a stone .. we always had a grinder at the abattoir to address notches or broken knife tips or wanting a particular edge .. I remember some boners used to custom shape the blade on a grinder as soon as they brought them . The Global you could most probably rub that out .

I got no idea whether it harms the metals etc .. but I’m slack 

Intelligence is like a four-wheel drive. It only allows you to get stuck in more remote places.”

carnarvonite's picture

Posts: 8560

Date Joined: 24/07/07

Stone and lot of sweat

Tue, 2017-05-30 17:30

Use a good quality sharpening stone and make sure you work on each side equally. Start on the coarse side giving a minute or so on each side of the blade to keep it even.
When you get all the nicks out and cannot see any of the old edge remaining then turn the stone over and start to polish the edge. Some like to increase the angle so that you get a chisel type edge so you don't roll the edge over if it gets too thin.

Remember not to put good knives in a dishwasher if you want to keep them sharp

Feral's picture

Posts: 1508

Date Joined: 01/11/06

 if you had access to a belt

Tue, 2017-05-30 17:37

 if you had access to a belt sander I'd be tempted to start with that but as mentioned above don't let the steel get hot.  a pro would probably only charge you $10 each so I'd let them do it 

Posts: 23

Date Joined: 10/03/07


Tue, 2017-05-30 19:02

 I got a worksharp belt sharpener $150ish and would never bother with a stone again. worksharp coarse belt would fix those edges in seconds

gruntre69's picture

Posts: 533

Date Joined: 15/10/16

Without a doubt

Tue, 2017-05-30 19:49

 The best way is a slow wet rotating grinder designed specifically for sharpening. I have a mate who makes knifes, very high end stuff.

We occasionally sharpen mine on this machine and get them to shave hair. It has a leather wheel on the other side.

They start at about $500 for a cheap one and go up to $1000 for the one he has..

Even on that machine it would take some work to gert those chips out...

I agree to take to somebody who has this gear...


 Marine trimmer NOR (available for clears, tops, carpet, upholstery, custom equipment covers)

Posts: 23

Date Joined: 01/01/70

with edges like that i'd give it to a pro

Tue, 2017-05-30 20:00

 fair enough trying to get an edge back if it was just blunt and you can give it a wirl yourself, but they look like they need alot of work and me personally i'd get it done properly to start with and then try to maintain it once it's done. I've done a couple of my knives at home on a new cheapish stone i bought which were blunt as and they turned out pretty good, but they weren't in the state of your knives so it wasn't that much work in the end. Also wouldn't touch a decent knife with a grinder, gave my bro in law a bayonet that i scored to sharpen up after he assured me he could get it really sharp, nob head took it to work and put it on a grinder and totally fucked it... never again! 

Jackfrost80's picture

Posts: 7906

Date Joined: 07/05/12

I used this guy and he did a

Tue, 2017-05-30 20:18

I used this guy and he did a great job for $5 per knife in my own driveway

The best thing you can do for your knives is keep them in a roll so that the better half is too lazy to get them out and will ruin a different one out of the drawer. I've caught my Mrs doing the following with my Scanpan knives: opening a tomato tin and snapping the tip, putting them in the dishwasher, cutting pizza on a pizza stone, gardening... now that I've got F.Dick, Global and Swibo knives I keep them safetly stored away.

Ben85's picture

Posts: 442

Date Joined: 20/11/11

100% agree. I use the same

Wed, 2017-05-31 12:52

100% agree. I use the same bloke.

I hide my good knives from the mrs these days, she now has her own set of globals that she abuses.

pelagicyachts's picture

Posts: 1266

Date Joined: 23/02/11

thanks guysthe good wife

Wed, 2017-05-31 08:20

thanks guys for all the feedback
the good wife bought some new knives last week, so these are surplus to requirements - I have 4 that are like this so will give it a go at fixing - I have a bench belt sander so will try the worse ones on that being mindful not to heat up the edge

what is it about dishwashers that damages the edges? is it the chemicals in the cleaning tablet?
our dishwasher has a dedicated cutlery tray - so all the knives lay flat or horizontalby them selves (rather than clumped in with other cutlery)


Jackfrost80's picture

Posts: 7906

Date Joined: 07/05/12

The powder is abrasive to

Wed, 2017-05-31 09:14

The powder is abrasive to give your dishes a good clean and is abrasive enough to take the edge off your knife.

My Mrs has proved this right time after time hence the knife roll in the bottom of the cupboard.

Posts: 73

Date Joined: 26/11/12

Problem one with dishwashers

Wed, 2017-05-31 09:25

Problem one with dishwashers is the knives get banged around. If you have a jig that clamps them in and protects the edges, problem two is that dishwashers, over time, kill handles, plastic more slowly than wood, but the heat helps moisture will find its way and degrades the plastic over time. The handle is a pretty important part of the knife too. Whether or not your dishwasher gets hot enough to affect the temper of the blade steel depends on your dishwasher and the steel, and while it might not, it takes like five seconds to rinse and wipe a knife by hand immediately after you've used it (before stuff dries on.) It's a good and an easy habit to form. It'll help you keep your knives sharper and they'll last way longer.

If you use a belt sander, go really really slow, don't use too much pressure, and keep some water nearby. It's easy to overheat the edge, where the steel is thin, and that will soften it, which is not good at all. Whatever you do, do not use the bench grinder. The big chip will take time, you may even want to work it out over several sessions if you can get the rest of the blade in usable shape.

pelagicyachts's picture

Posts: 1266

Date Joined: 23/02/11

thanks guys - some great

Wed, 2017-05-31 14:09

thanks guys - some great information -


Jackfrost80's picture

Posts: 7906

Date Joined: 07/05/12

It's actually quite relaxing

Wed, 2017-05-31 15:28

It's actually quite relaxing stoning a knife. My Scanpan ones were similar to your Global one (been using one of those pull through sharpeners?) and it took about 20 minutes or so. Comrad game me some great advice in another post on here.

Don't forget that Jap knives like Global are sharpened at around 10-15 degrees compared to your Swibo which is sharpened at 22.5 degrees.

pelagicyachts's picture

Posts: 1266

Date Joined: 23/02/11

thanks mate - a lot more

Thu, 2017-06-01 09:17

thanks mate - a lot more technical than I would have imagined but no doubt an art as much as fishing is

Walfootrot's picture

Posts: 1386

Date Joined: 23/07/12

We spend good money on

Thu, 2017-06-01 11:50

We spend good money on knives, wash them by hand, dry and pack away, maintain the edge on a steel and when needing to maintain the shoulder dress on a stone.
The chips on these knives need to be dressed out, new shoulder on a stone then hit with the steel.
May be best to give them to someone who has the knowledge to bring them back to life.


More drum lines, kill the bloody sharks!