Tag Archives: zdp-189

Spyderco Stretch C90CF – Part III – EDC of high performance

Spyderco C90CF ZDP189

So after the initial impressions and the convexed edge enhancement how the C90CF is performing on a daily basis ?

The first thing wich stands out in this folder is how flat and confortable it is to pocket. This is the kind of knives you totally forget once clipped.
The second thing is how easy it is to put in action. The oversize hole and the relatively heavy butt handle and the smooth action make it a great spyder drop opener if your carry it (like myself) with the clip mounted near the pivot. The grap the hole between the thumb end the index and in a fluid motion the knife is open in your hand, ready for any chore.

Spyderco C90CF ZDP189

Now the thin blade is a laser. Again the thin cuts through all materials submitted to it with ease and, good news, the little vertical play of the backlock seems to have disappeared with the breaking in and the constant use. Now the knife feels rock solid. Also the thin edge on the thin blade doesn’t need a lot of force to cut deep.
The ZDP 189 edge seems to lose its hair popping sharp sharpness fast but the working edge seems to last forever. Another good news, leather bely and compound is enough to bring back the hair popping edge in a matter of seconds. So far I was not able to ruin the edge: no chipping, no bending, no excessive dulling. My edge is polished and convexed and it cuts, cuts, cuts:

Spyderco C90CF ZDP189

Some very hard cardboard tube is no match for the Stretch thin blade.
Also I got no discoloration or pitting on a ZDP189 blade which has been used a lot in the kitchen. It has been cleaned by rinsing under water and wipe just after.

All in all the Stretch is an incredible high performer. It’s relatively long blade makes it really useful for a wide specter of chore and his polyvalence will be hard to match. This is really great folder to EDC.

Rockstead Higo-J in the spring time

I don’t have cherry trees or I would have pictured the Higo with some cherry tree blossoming… but here we got roses almost a month earlier !
So it was the occasion to picture the blade in the middle of them.
As you can notice, the Rockstead quality is something you can mesure in time. The knives which has been included in my EDC rotation and my hicking in the woods, did not suffered from his chores. The mirror polished blade is still perfectly intact. The lock up is secure and there is no play.
Now ZDP-189 is a very nice steel on the long run. I mean by “nice”…. “gentle” !
Using a Paramilitary 2 Sprint Run with a blade S90V, this last is a bear to get sharp. As Sal Glesser said S90V do not want to give away molecules.
ZDP-189 which I EDC with the Michael Walker and the Rockstead is “gentle” as I can polish it. (I was not able to do that yet with S90V.
The Higo is a very pragmatic knife, it is made to get dirty and to be clean easily. WIth his incredibely hard blade, I did not have any issue to keep it razor sharp in the woods. The choil makes it a very precise knife for wood cutting. You can applied a lot of force in confidence and the handle is very confortable despite it’s open fram structure.

Spring is the time for cleaning. I have used my Higo to cut hard plastic before to have it recycle. I was able to try to compare ZDP with S90V.
I’m very confident, even with a 66,6 HRC ZDP when I’m still very careful with S90V at 60HRC. S90V is like a “alien” steel, it can stay as sharp for “strange” reason I can not quantify even if I can qualify it, knowing how the steel carbid matrix is reinforced by vanadium…
ZDP on the other side both on the Michael Walker and the Rockstead got at first some micro chipping issue, but once resharpen never shown any more unreliability.
Oslo I was not able to get any patina on ZDP and my main way to keep it sharp is some white compound on a leather belt.
It’s razor and don’t want to give up.

My only little complaint is the shape of the clip but this is really not a big issue as I have prevent any scratches it could have done. (That was not the case on my various Sebenza clips wich has been very nasty on car paint…).
All in all after eight months of use, the Higo-J is still like a new knife. I was not able to scratch the handle, despite my rings on my left hands. The blade stay sharp with easy maintenance. The lock up is secure and the feeling of using a fixed blade is very strong.

Rockstead Higo-J ZDP-189: fears and cures

My ZDP189 Higo blade was “chipping” today (!!!) quite badly on the tip (Arrrrgh!!!). So I have decided to passe it gently on a Spyderco white ceramic rod before to strop it for a good hour on leather and compound.
Now it’s much sharper than before (!) and I know my edge is stronger with a little convexing which should prevent it from rolling…
Amazing grind ! Amazing steel !
ZDP-189 is very forgiving.
I don’t know how the chipping appeared as I did not use the knife hard (yet). I think it came from the very thin hard edge on the tip and perharps one fumble of mine.
Now it’s “cured” and fixed !
(I did not pictured it when it was a mess as I was much to concern about fixing it.
Perhaps the edge touch something hard I did not notice ?
I don’t know.
Anyway:

Notice how the “chipping” on the edge start to be erased by the ceramic shouldering.

now it’s all fixed:

The more I think about it (and when I see how I could fix it)
I think it was the very edge which rolled “chaotically” giving the look of a bad chipping but which could be fixed with a light sharpening (without removing matter)
The edge has touched something hard (it’s happen at the tip and this could have happen without me to notice it)
It happen once to me with another knife (mirror finish, thin and stainless) I was testing by cutting bambu and I completly ruined the edge: it was almost serrated after my ten cuts…. but I was able to realigned the edge and the damage was almost invisible after and the high sharpness restored.

My other ZDP-189 blade is the Chris Walker which is not as “smooth” sharp as the Higo but so far di not rool or chip. (It’s not as hard as the Higo-J though)

“The bottom of this blade edge is 30 degrees, and it’s continuously change to top of the blade.The top edge’s angle is 24 degrees.”
30 degree (15 by 15) with a very hard steel can be tricky when the edge is brend new.

Anyway I gently realigned the edge with white ceramique and strop it a lot.
I my have created a secondary (and stronger) edge, but the stropping should minimize its effect in pure sharpness loss.

Any knives are made to be used. It’s easy to hit something which alter the edge. A good tool should be able to withstand that, get fixed and ask for more.
The Higo-J, as an excellent tool, is no exception.
Bob Terzuola says: “If you knife is still sharp, it means you don’t use it enough !”
So let’s use it !

Researching the Rockstead site:
“We realized the best edge angle near the haft of the blade is 30 degrees and in the point of the blade 24 degrees.(We adjusted the angle to 30 degrees in the haft side because power was most concentrated there, which improved toughness, and 24 degrees at the tip of the blade, where power was low. The angle changes continuously.)”

Ok the angle at the tip is shallower (24°)… that’s why the tip is more fragile … Good to know.

The road so far:
“Rockstead Higo-J part I – A Folding Masamune in Paris”
“Rockstead Higo-J In the woods”
“Rockstead Higo-J: Part III – Masamune in Winter”