Beiträge von kwakster

Spyderco Southard with CTS-204P blade, which has been in use for a few years now with a Dutch scout leader.
It has already been sharpened several times by him on stones, plus two times by me on Paper Wheels (once up to 6 micron diamond compound, and once up to 15 micron diamond, the latter performing noticeably longer for the owner)

This time the knife was reprofiled from about 30 degrees inclusive to 25 degrees inclusive with a standard Paper Wheel with 220 grit SiC, then deburred with a second Paper Wheel with 0.25 micron diamond compound.
This produces a polished semi-coarse edge with an aggressive bite, as the knife is going to be used to cut a lot of 10 mm polyprop rope in the coming weeks.
You can click the pics 2 x for a bit more detail.

Update:

The owner just informed me how the edge on his Southard is doing so far.
He had used the tip of the knife to cut open about 50 dusty/dirty cardboard boxes filled with porcelain mugs, and this resulted in blunting that tip to a point that it could only barely cut copy paper.
But according to the owner this was most likely due to the fact that the tip hit the mugs every now & then.

After all 50 boxes were opened & emptied the Southard was used to cut down each box, which he measured to be a total of about 80 meters or 262 feet of cardboard.
Afterwards the edge was still able to easily shave the hair from his legs (except about 15 mm of the tip), and the owner feels that the knife isn't due for a touch-up yet.
He also noticed that the CTS-204P steel holds this edge noticeably longer than the S30V steel in his Spyderco Sage, which he had sharpened himself and used earlier for the same job.

The knife was lent to professional sous-chef Patrick for about a month, and below are his findings.
I translated what he mailed me from Dutch into English as precise as i could:

Update 1 (after 1 week of use):

I used the knife for 4 consecutive days straight as my only knife, and then for 2 days for odd jobs in between.
The edge is still reasonably sharp as long as i keep slicing, but when i use it the way i was taught in chef school (like a locomotive) i notice it is less sharp than in the beginning.

Here is a list of things i cut with it during those 6 days:

Day 1:

6 pineapples
2 melons
14 kilo steak
12 kilo rhubarb

Day 2:

3 kilo peaches
4 kilo salmon
1 kilo onions

Day 3:

1 kilo of salted ham
1 kilo feta cheese

Pictures of the knife, taken by Patrick on day 3:

Day 4:

10 kilo large carrots
3 kilo onions
2 kilo tomatos
2 kilo cucumber

The knife cuts well, but what is remarkable is that when i cut like i was learned i can feel that the knife chooses it's own direction, like a knife sometimes does when the tip is bent.
(an a-symmetric blade can have a tendency to do that in certain situations - kwakster)

But as you can see i did both rougher & finer work, and the edge remains in very good shape in my opinion.

**********

Update 2 (after a month of use):

I have been using the knife on every single working day (5-6 days in one week), and i think the edge is now come to the point where it doesn't get any more blunt.
I didn't notice any difference while cutting and i also can't see any changes in the edge with the naked eye.
It is exactly as you told me: i can still cut tomato's with it !
But only with a slicing motion, as when i try a different cutting technique i can notice that the edge is less sharp.

All in all i think it's a very nice knife (which took me a while to get used too)

BTW: Sous-chef Patrick usual knife is a Sakai Takayuki VG10 Santoku 18cm

The knife has been used for about a month during our holiday in Germany & Austria for cutting all kinds of food on a simple plastic cutting board.
It performed perfectly until one of the last days i tried to slice one of those large German breads: very good food, but these have quite hard crusts.
Parts of the edge rolled a bit, but no chipping as i more or less had expected.

Back at home i resharpened the edge in 3 steps: Rubber Wheel with 230 grit diamond powder, Paper Wheel with 15 micron diamond compound, Paper Wheel with 1 micron diamond compound (deburring)
The result was a treetopping sharp edge, and in this condition the knife was then loaned for about a month to a professional chef.
More to follow.

This brand new Endura ZDP-189 sadly had a less than optimal factory edge, and since this beautiful steel deserves better i reprofiled & sharpened it myself.

My guess is that these knives are belt sharpened and then have the burr stropped of on a buffer.

On this knife however it seemed like the buffer ran out of cutting compound (or the sharpener just did a sloppy job), as through my loupe i could see remains of a burr almost along the entire edge. (some of it is partly visible in picture 2)

Due to this the sharpness was of course severely lacking.

I also measured the edge angle to be 35 degrees inclusive, which i think is a bit too large for a folding knife in ZDP-189 steel.

Before sharpening:

First i removed the old apex by cutting a few times straight into a silicon carbide stone, then reprofiled the edge to a slightly convex ~ 25 degrees inclusive angle with a Paper Wheel coated with 15 micron diamond compound, and finally removed the tiny burr with a second Paper Wheel coated with 0.25 micron diamond compound.

This leaves the scratch pattern created by the 15 micron diamond particles intact as much as possible, creating an edge that with the naked eye almost looks like a mirror, but which has the bite of a coarser edge.

I call this a "bling & bite" finish, and i have found it to work very well in EDC use on harder high carbide steel types.

It's also quite difficult to show correctly in pictures, as the lens of my cheap camera has a tendency to show more of the scratch pattern than can be seen in reality with the naked eye.

With the reduced edge angle & the much finer edge finish the knife will not only cut in a completely different league, it can now also be kept sharp on the 30 degrees slots of a Spyderco Sharpmaker or Lansky Turnbox.

After sharpening:

Specs:

Length open: 22,2 cm

Length closed: 12,7 cm

Blade length: 9,6 cm

Blade thickness: max 3,0 mm (ricasso)

Edge length: 8,8 cm

Steel: ZDP-189 powdered steel

Hardness: 64-65 HRC

Weight: 103 gram

Handle material: British Racing Green FRN on steel liners

A while ago i sharpened this one for a Dutch forum member:

Edge was done on Paper Wheels with diamond compounds exclusively, and the new & slightly convex edge measures +/- 30 degrees inclusive.
Very useful little knives with well hardened S30V steel.

Finally found the time to finish the edge with 1 micron diamond compound, and the edge can now whittle chest hairs towards the point along the entire edge and also slice a tomato quite well.

https://www.youtube.com/watch?v=q4YGGHltloU

https://www.youtube.com/watch?v=dP6fNB_obN4

Time to find out if and how this edge will hold up in our kitchen use,

Post from someone on Bladeforums:

"According to CRK at the booth at Blade yesterday, Aceco does their heat treat.
They have been running their blades 59-60 RC for about two years now (not sure of the exact date, maybe August 2013), they have just not updated their web site.
If you look at the Inkosi it says 59-60, while all the others say 58-59.
I noticed this and asked about it"

If you can't find a sharpener in Germany and you don't object to sending knives to the Netherlands maybe i can help out.
I'm fairly proficient with Paper Wheels.

Some time ago i did this rather large Strider fixed blade in S30V steel for a Dutch forum member.

According to my Tormek angle gauge the factory edge measured 50 to 55 degrees inclusive and it wasn't very sharp either.

Grit progression: reprofiled on a standard Paper Wheel with 220 grit SiC, refined it a little with a second Paper Wheel coated with 15 micron diamond compound, and finally removed the tiny burr with a third Paper Wheel coated with 0,25 micron diamond compound.

The new & slightly convex edge measures around 35/36 degrees inclusive, and can both slice single layer toilet paper and treetop the hairs on the back of my hand.

Zitat von Nightstalker

kwakster Sorry for that really stupid question... But what is Paperwheel sharpening? I really didn't heard that before... But I'm really interested because the edges look really nice!
Regards

Basic sharpening with a standard set of Paper Wheels is shown here:

I started sharpening with a set like this in 2009, bought from Armin Dobstetter from Custom Leather in Germany:

http://customleather.ellvis.de/index.php?go=detail&ID=1001

If you or anybody else has any questions about what you see here, fire away,

A Chinese Ganzo 704 as i received it from Hong Kong:

A very nice knife for the money (i paid about 17 US dollars including shipping from Hong Kong to the Netherlands), but with quite an obtuse edge angle of about 35-40 (ish) degrees inclusive and also a bit blunt not a very good cutter.

On the blade it says 440C stainless steel, but it's more than likely it's Chinese cousin 9Cr13MoV.

Reprofiled with a standard Paper Wheel with silicon carbide grit to 30 degrees inclusive, refined it just a bit with a second Paper Wheel coated with 15 micron diamond compound, and finally removed the tiny burr with a third Paper Wheel coated with 1 micron diamond compound.

It cuts hair above the back of my hand and can slice single layer toilet paper.

A while ago i reprofiled & sharpened this Ontario Afghan Bush in (probably) 5160 steel for a Dutch forum member, who when he received it tested it quite rigorously to see how the the knife would hold up with it's new edge.

The pictures show the knife with it's new edge measuring 35 degrees inclusive, a 15 micron diamond compound Paper Wheel finish, and a treetopping sharpness.

This was the mail i got from him when he was done testing:

(translated from Dutch)

Hereby i send you the results of the batonning test: my arm hurts and the knife just laughs at me.

I started with batonning through some standard firewood, which didn't cause any problems.

Then i proceeded to baton right through a hardwood pole with a big burl (?) in it (with a lot of effort from my side)

I then replaced the baton with a hard rubber hammer for a bit more comfort and hitting power, and with this i managed to drive the edge about half an inch crossgrain into another piece of tropical hardwood.

After this i cleaned the knife, and the edge would still pushcut through paper.

I almost forgot to mention that i also put the knife sideways with the point on a wooden block and gave it about 20 hard whacks with the rubber hammer on both sides of the knife.

Then i tested the point strength by stabbing it into hardwood and breaking it free sideways.

I think the knife already has endured more than it will ever have to in real life.

After all this i could still shave the hair on my leg on skin level, and after a bit of stropping it could treetop again.

Since 2009 i've been sharpening knives on Paper Wheels, and i hope i'm not i'm the only one on this forum.

From time to time i will post my results here and i hope that others will do the same,

Here's one i did a few days ago, a Spyderco Paramilitary 2 in Elmax steel.

The factory edge had some light brown discoloration near the tip on one side, traces of some unknown black stuff that couldn't even be removed with acetone (visible in pic 1 & 3), and it could also barely cut copypaper.

This is how it looked before sharpening:

First i removed the apex of the old edge by cutting a few times in a silicon carbide stone, then resharpened it with a Paper Wheel coated with 15 micron diamond compound, followed by removing the tiny burr with a second Paper Wheel coated with 1 micron diamond compound.

This time i also polished the bevels a bit more with the same Wheel, just to see how the Elmax would do.

According to my Tormek angle gauge the new edge measures 30 degrees inclusive, can slice single ply toilet paper and easily whittle the hairs on the back of my hand from heel to tip.

A guy over on British Blades had this to say about the material, and for the most part i tend to agree with him:

"Cera Titan
Now this is a weird material, its a Titanium composite with large quantities of carbides.
As the Ti wears away during use the knife loses its shaving hair edge about as quickly as 440a/6a grade steel, thus not at all impressive.
However, the edge left is a carbide chainsaw of cutting power !
This knife looks and feels dull after a good work out at some cardboard boxes, yet still cuts like the Devil himself !
I note the grind almost rounds the tip, suggesting that while this is much more flexible and tough than the ceramic models this is not a blade for cutting nails or dropping...
In my opinion the better choice over ceramic blades.
Much like Talonite, Dendrite cobalt alloys, only less expensive and probably a little tougher.
I like this material and it will not rust, ever."

IMO the knife is however much tougher than it looks & feels, and dropping it will definitely not result in breaking the blade (wife dropped it twice on hard laminate)
If however it falls edge first on a tile floor i guess it could sustain a damaged edge, but given the relative flexibility of the blade i don't think it will be in the order of magnitude as could be the case with full ceramic blades or full hard Japanese kitchen knives in white or blue paper steels.
The difference lies in that very resilient titanium matrix.

Mine is still being used in the kitchen almost every day, and the edge is still sharp enough to slice tomatoes.
Everyone who uses it here likes it for it's ultra-lightness, the fact that it's totally corrosion proof, and women especially like the fact that it looks harmless because of the short and bluntish santoku-shape.
Sharpening to armhair shaving on skin level can be done with just silicon carbide, but for refining all those cubic boron nitride particles and vanadium carbides in the titanium you absolutely need fine diamond compounds and/or sprays.
Doing this will reward you with a thinner apex that makes the knife cut even easier.

Just got word that mr de Beer sold his company know-how about Rubber Wheels to these guys based in Ireland:

ATTO ABRASIVES LTD.
DUNMAIN,NEW ROSS
CO.WEXFORD
IRELAND

Website: http://www.attoabrasives.com/

My workplace is in the back of our small cellar, which we also use to store our bikes and other stuff we don't use on a daily basis.
So nothing fancy as you can see

Overview:

My Tormek T7 wetsharpener fitted with an SB-250 Black Silicon stone:

My red Creusen DS7500TS benchgrinder with Paper Wheel coated with 220 grit SiC on the left, and my still experimental Rubber Wheel coated with 230 grit diamond powder on the right:

My collection of different Paper Wheels & Rubber Wheels:

Most edges are indeed freehanded on the Tormek and the various Paper Wheels/Rubber Wheels, but for certain types of edges like tanto's (as well as scissors and chisels) i use the Tormek with jigs, like on this Strider GB:

As you can see i didn't refine the scratch pattern on purpose (as i think it looks good on a knife like this), only removed the burr on the Tormek leather honing wheel, followed by some stropping on a leather handstrop coated with 6 micron diamond paste to create a slightly convex microbevel.
The straight part of the edge now measures around 25 degrees inclusive while the slanted part is about 30 degrees inclusive.

The (semi-polished) mirror edges i put on knives are best maintained on hard leather or MDF strops coated with some diamond compound, but on many working knives i don't put a mirror edge.
Most Chef knives for instance i do for restaurants only get sharpened on the Tormek with the silicon carbide stone graded to about a 1000 grit, as based on feedback that finish seems to work both the best & the longest.

Here's an example of how i use the diamond powder from Yuriy.

The knife is made by Ewout vd Gronden (E.A.G. Knives), a Dutch part-time knife maker who spends a lot of thought, time and effort into making about two knives a month.
For steels he likes to use D2 and N690Co which he hardens himself with very good results (i've tested a few of them in the field and provided him with feedback)
After he finishes a knife he sends it to me to give it the final edge.
He also lets me know his wishes regarding edge angle & edge finish, and i go to work.

This is one of his larger field grade knives i did recently, and the picture was taken by the maker before i put on the edge.
Steel is N690Co, blade is 18 cm long, and the handle is canvas Micarta.

These are pics taken by me with it's new edge, in this case of a pre-specified and almost exact 35 degrees inclusive.
Bevels were ground with the Rubber Wheel coated with 230 grit diamond powder, after which i only removed the tiny burr with a Paper Wheel coated with 1 micron diamond compound.
This provides for a strong edge that is literally treetopping sharp along it's entire length, yet still has a lot of bite.
(pics can be clicked 2 x to get a better view of the scratch pattern the 230 grit diamond powder creates)

Since i'm a fan of using diamond products for sharpening & polishing knife edges i'm always looking for good sources.
A few months ago i found this small US company: http://techdiamondtools.com, and they also have a Facebook page: https://www.facebook.com/lapidarypaste

Owner: Yuriy Ma
Address: 10511 Glencoe Drive
Cupertino, California
95014 USA

I exchanged a few e-mails with Yuriy and bought 100 carat (about 20 grams) of 230 grit diamond powder from him, paid with Paypal and received my order in about a week from the US, neatly packaged in a double plastic pouch inside a small bubble envelope.
I'm currently using the powder glued to the surface of a Rubber Wheel for sharpening ceramic knives and various high carbide steels, and i must say with very good results so far.
When my stock of various diamond compounds runs out i'm also going to order some from here.

Now i'm not sure if i put this in the right place on the forum, i just wanted to share this useful information with my fellow knife afi's here.
If it's not allowed please move it elsewhere or remove.

For the last month and a half i've used the Forever Titanium Hybrid knife in our kitchen almost exclusively (coupled with a reground Spyderco paring knife), and i must say i'm quite pleased with it.
The model & size are very handy for what i use a kitchen knife for, it cuts very well because of the thin blade geometry & 25 degrees inclusive edge, and the blade material keeps a slicing edge for a long time.
Today i resharpened it for testing purposes, even though the old edge was still sharp enough to cut tomatoes.
As far as i could see through my Victorinox loupe the blunting mechanism seems to be microchipping, but this happens only very slowly and on a very small scale.
The chips aren't visible with my naked eye and are actually helping to prolong the aggressive slicing edge this material naturally seems to like.

Since i wanted to find out how silicon carbide would do with this blade material i took it to my trusted Tormek T7 fitted with the SB-250 Black Silicon stone, and to keep it short: the stone ate the Cera-Titan for breakfast.
My stone is graded to about a 1000 grit, and in only a few slow passes per side i had a nice burr.
Removing that burr took noticeably more time (the titanium matrix is very resilient), but with some 1 micron diamond compound on the leather wheel i managed to slowly abrade it away.
The resulting edge could just shave the hair on the back of my hand on skin level, which differs from the same sharpening procedure done on a good VG10 kitchen knife, as that almost always produces a treetopping sharpness.
Now i haven't tested this edge in our kitchen, just cut some triple, double, and single layer toilet paper, which it all did just fine.

I then proceeded to refine the edge with 15, 6, 3, and 1 micron diamond compound, all on dedicated Paper Wheels, and the edge can now whittle one of my chest hairs in the direction of the root, not towards the hair point.
It also slices single layer toilet paper very well.
Maybe the material can get even sharper with more refinement and/or different methods, i don't know, but i'm also not sure if that would even be useful, knowing how this material tends to behave.
My guess is that the current sharpness will also vanish quickly again to settle for a long lasting working edge, but i want to find out if the extra refinement steps make any difference in that degrading process.
My plan is to use the knife with this edge until i can no longer slice a tomato well, which to me is a good test method for a kitchen knife.
Later i also plan to lend the knife for a while to a professional Chef to see what he thinks of it, with a fresh edge of course.

Yesterday one of the Chefs i sharpen kitchen knives for on a regular basis decided to treat himself to a brand new Sebenza 25 from a well known Dutch knife shop.
As many here know the Sebenza is a beautifully designed & manufactured knife, and the model 25 may very well be considered the current king of the hill in the series.
Sadly the factory edge on the first example the Chef got to handle was just plain blunt, and upon inspection it turned out that the other 4 or 5 Sebenza's 25 that the shop had in stock suffered from a comparable bluntness.
To cut a long story short: in the end the Chef liked the knife so much that he just bought the least blunt one, while the shop assistant promised to contact CRK to see if the other knives could be sent back.

Anyway, today the Chef contacted me to ask if i could do something about the edge on his knife.
The first thing i noticed about the blade on his model 25 is that it seems to be ground a hair thinner behind the edge compared to previous Sebenza's 25 that i've handled and sharpened, and that as a result the edge bevels were quite narrow, even with a measured inclusive edge angle of 35 degrees.
The second thing i noticed (with my Victorinox loupe) was that the edge reflected light almost along it's entire length, and i couldn't even cut a piece of copy paper with it.
Now i think that the edge wasn't completely apexed, but with only my loupe to judge by i'm not 100 % sure.

In a conversation with the owner and also because the knife is brand new we came to the conclusion to give it a new edge that would resemble the factory edge as much as possible, and to make it seem as best as i could that nothing was done to the knife.
First i removed the blunt apex of the factory edge by cutting several times into a silicon carbide stone, after which i gave it a completely new edge with an experimental Rubber Wheel with 230 grit diamond powder.
Finally i removed the tiny burr with a Paper Wheel with 1 micron diamond compound.
The new edge again measures 35 degrees inclusive from heel to tip, survives a few cuts into my laminated test block without visible damage, and can still easily treetop the hair on the back of my hand.
I think the owner will be happy when he comes to collect his knife tomorrow morning.

Before sharpening:

After sharpening: