Sharpening/Thinning Clad Knives...Am I Just Being Dumb?

Eli Chaps

Eli Chaps

Joined
Apr 20, 2018
Messages
4,458
There's a few kitchen knives over the years that I've been interested in the design, size, etc. but have avoided due them being made in clad steel. I've always been afraid that I'd inevitably have to thin it out to keep the cutting steel revealed and the blade "thin".

I don't have water stones but do have ceramics, diamond, and Arkansas. I'm thinking I could tackle thinning with the ceramics and Arkansas for smoothing out. Yeah?

Right now I'm looking at one with a VG10 core so I it should wear well. Maybe having to even perform the task is so far into the future as to not even be a concern?

Am I worrying about something I shouldn't be?

As always, thanks for any insight. :)
 
I am not sure what exactly you're asking but I have a HAP40 clad in 410 that BBB thinned out quite a bit and it has no issues. The clad steel is softer so thinning it out would not be an issue. I don't think there is anything to be concerned about here.
 
First, do not use ceramics or Ark stones. The ceramics can cause damage and the Ark's will hardly do anything to the hard stainless steel.

If you want to keep it cheap buy a King 800/4000 combo stone for sharpening and when it comes to thinning just send me an email. Thinning is not as simple as most make it out to be and someone without experience or guidance can do more damage than good.

As for the need to thin? I wouldnt worry about it for at least two years. After two years you will probably be to a point where thinning will help the blade geometry which will be thickened with repeated sharpenings. Thinning also depends on the individual knife so, knowing which knife exactly is important.
 
Diemaker said:
I am not sure what exactly you're asking but I have a HAP40 clad in 410 that BBB thinned out quite a bit and it has no issues. The clad steel is softer so thinning it out would not be an issue. I don't think there is anything to be concerned about here.
Click to expand...

What I was rather ineptly trying to get at is that as you use and sharpen the knife, the edge "moves" up the blade and eventually the geometry and/or the lack of exposed core steel will force you to thin the overall blade. This is true of mono steels too of course but with those you obviously don't have the added "complexity" maybe is the word, of the cladding to deal with.

I've always been concerned that ceramic stones would just be too aggressive on the softer outer core and I'd end up with a mess.

Jason basically confirmed that. So I'm still dumb, just about other things. :D
 
I should also add... What ceramic stones are you talking about? There are ceramic waterstones like the Shapton Pro and Gass but I would bet you're talking about a sintered ceramic?
 
Jason B. said:
I should also add... What ceramic stones are you talking about? There are ceramic waterstones like the Shapton Pro and Gass but I would bet you're talking about a sintered ceramic?
Click to expand...

Yeah Jason, just run of the mill sintered. Crystolon, India, etc.
 
Welp, I thought I knew what sintered ceramics were, but now I'm confused when crystolon, india, etc are used in the same sentence.
 
jpm2 said:
Welp, I thought I knew what sintered ceramics were, but now I'm confused when crystolon, india, etc are used in the same sentence.
Click to expand...

Well, it's entirely possible I'm confused here. I do know sintering. Not with sharpening stones but with high purity powders. But it's basically using heat and often times pressure to take powders, in the case of these materials pretty large stuff, and form them into a solid. You get material flow without going molten. This binds everything together. You may well already know all that and I'm sorry if so.

I just always assumed these stones were produced through sintering as I don't think there is any binding agent used.
 
Eli Chaps said:
Well, it's entirely possible I'm confused here. I do know sintering. Not with sharpening stones but with high purity powders. But it's basically using heat and often times pressure to take powders, in the case of these materials pretty large stuff, and form them into a solid. You get material flow without going molten. This binds everything together. You may well already know all that and I'm sorry if so.

I just always assumed these stones were produced through sintering as I don't think there is any binding agent used.
Click to expand...
I guess that might be the case but often time I hear talk of binders. It could be these binders are used before the firing process and burn off?
I hear not to use oil with a waterstone due to the binder?
When I think sintered, I think of Spyderco aluminum oxide stones, and other non porous types.
I guess I need to read up on this more, thanks.
 
Spyderco stones are sintered. Sintering can surely produce porous materials. In fact, that's often the enemy that you're trying to defeat.

I suspect Spyderco uses very fine powders and relatively high pressure.

Basically, you put your material into a die of some type and apply heat and again, pressure, for a desired time. The material flows and adheres to itself so no binders. Larger starting material or perhaps combinations of larger and very fine can produce different end results.
 
Also, I've never thought of silicon carbide as a ceramic, but maybe it is.
I might have been mistakenly relating only aluminum oxide to ceramic.
 
Metallurgy is an awesome science that still has a lot of mysteries around it. We can know things happen but not know why. Within this discipline is the specialization if you will of ceramics. Ceramics are quite complex and I basically just said about all I know about them. :D

There's lots of different elements that can form ceramics, both metal and non-metal. But again, that's getting way past my understanding.

Heck, while we're at it, let's ping a real metallurgist! @Larrin ???
 
Eli Chaps said:
Maybe FortyTwoBlades FortyTwoBlades and @DeadboxHero can shed more light on these specific products and their production.
Click to expand...

India and Crystolon stones are vitrified bond, which means they use a clay binder that's fired to a "glassy" state, holding the abrasive grains in place. Sintered stones use no binder, and only trace amounts of sintering aids, using such enormous heat and pressure that they fuse the very fine powdered material into a cohesive solid. This is why sintered materials so strongly resist the shedding of any grit--they are essentially synthetic sedimentary stones. Aluminum oxide and silicon carbide are, themselves, ceramic materials, and the binders used in vitrified abrasives are also ceramics. As such, they could be called "ceramic" stones, but a disambiguation to use would be "ceramic bond" since in the knife and tool world "ceramic" is usually taken as shorthand for "sintered ceramic". Sintered abrasives have such a hard structure that they can exert excessive point pressure on the edge of glassy-hard laminated blades, but if the edge core is done either in sufficient thinness and/or in sufficiently durable hardness and treated with the proper low pressure you can use sintered stones with laminated blades without incurring chipping issues.
 
Thank you Benjamin.

I'd never given much thought to the Norton stuff and as I said, just made the assumption about sintering.

So much to learn. And such a great place to learn it! :)
 
In light of what's been presented here, I'm going to have to be more careful how I use, and respond to the word "ceramic".

In the past when it came to sharpening stones, I've always had aluminum oxide in mind when referring to ceramic, whether sintered, vitrified, or resin bonded, but never silicon carbide. Live and learn...
 
Eli Chaps said:
Thanks J jpm2 for provoking the conversation.
Click to expand...
Thanks for not minding.

Back to the subject, the only laminated blades I have are the Spydercos Diemaker mentions, and an older mora.
Haven't used or sharpened the mora much, but the Spydercos have been thinned, sharpened, and reshaped a lot.
I've used diamond plates, diamond bonds, Norton crysolons and their aluminum oxide stones, cheap ace hardware aluminum oxides, and spyderco sintered ceramic without any issues, other than aluminum oxide not cutting very well.

I guess I don't really understand the concern, is there something different between other makers laminated steels and Spydercos when it comes to type of abrasives used?
 
You must log in or register to reply here.
Back
Top