Spyderco Forums

Even in Tucson, mine is developing just a hint of a golden brown -- nothing worthy of a photo yet. Coincidentally I carried it in my pocket all day today, even though I received my Rex45 Military in the mail yesterday. That should tell you something about how much I enjoy the Police 4.

The Meat man wrote: ↑

Sun Dec 02, 2018 10:11 pm

Vivi wrote: ↑

Sun Dec 02, 2018 8:42 pm

The edge holding of K390 is really impressing me, both in how easily it sharpens while having superb edge retention.

Since reprofiling the knife, I've only touched it up once on my medium bench stone. Only three or four strokes per side, aiming for a 15 degree micro bevel.

Made that video, took it with me on four other camping trips, sliced over 1000' of cardboard, sliced up some of those green scouring pads (They're very hard on knife edges), lots of food prep and more.

Still shaves.

I can see why Sal chose this steel. It makes a very nice blade for a pocket knife. Might not be a full time carry come next summer, but I have my Pacific Salts for that.

That is impressive.

Curious, what edge angle/ grit finish did you reprofile it to?

Freehand, aiming for 10dps. Have not verified if it is that thin, but I do plan to run it a little thinner sometime soon.

I finish it on a Spyderco medium bench stone or my medium sharpmaker rods. I have not tried running a polished edge with K390 yet, but in general carbon steels seem to work better with them than high carbide stainless steels like S110V, so I'd imagine it would do well with one.

I find the medium stones are about the perfect mix of polish & toothiness for my EDC knives.

My P4 got a little rusty out on a hike today.

Let us know how that cleans up. That's kind of similar to what I see on my cruwear pm2 occasionally (which never sees salty conditions - strictly a woodcarving/inland knife) and it cleans off easily.

My Police4 started with the patina immediately, and M4 usually takes borderline neglect to patina where I live. The deep/coarse grind lines on the P4 blade make it harder to casually wipe clean, which probably aided the corrosion. I haven't seen any pitting or substantial rust though, despite a few rain hikes and lots of plant matter left on the blade from yard work.

Regardless of this, K390 on this knife has been my favorite steel experience to date. This thing cuts like a scalpel and loves to get stupid sharp and stay there. Please give us some more K390 to play with :) I'll buy any locking folder with it, but a PM2 would be nice if I'm getting picky. DLC if I'm being extra self centered

EDIT: Sorry if I'm starting to sound like a broken record!

The K390 blade on my police initially impressed me with its corrosion resistance cutting foods etc. It got a mild cloudy patina that was only visible in the right light.

Unfortunately the steel doesn't handle sweaty pockets. Probably going to be using it for household chores only the next few months. I'm getting a line of rust spots along the blade, and the liners seem to be building up rust unusually quick on the inside next to the blade.

The corrosion on the blade isn't too bad, but taking it down to scrub the liners every few weeks would get old fast. Pocketing my Pacific Salt today.





Hope that VG10 lightweight hits soon.

Here's some more photos.

Pivot:




Middle of the handle:



Lock release:





Blade:



It's kind of weird. The corrosion on the blade isn't as bad as I expected, but the liners are rusting abnormally fast. I wonder if the carbon steel blade is causing some sort of reaction, or if the liners are made out of a different material than they typically are?

Either way this one is getting swapped out for my DLC Manix XL for now. I'll be rotating between that and my Pacific Salts.

Interesting.

Vivi wrote: ↑

Sun May 05, 2019 1:51 am

It's kind of weird. The corrosion on the blade isn't as bad as I expected, but the liners are rusting abnormally fast. I wonder if the carbon steel blade is causing some sort of reaction, or if the liners are made out of a different material than they typically are?

I asked back in March and couldn't get a response (http://forum.spyderco.com/viewtopic.php?f=2&t=83235). Mine were not as bad as yours, just with black splotches. Still, I have no other Spyderco liners behaving like this with similar usage, even very old ones. I assume the P4 liners are some carbon steel.

Roland.

ferider wrote: ↑

Mon May 06, 2019 4:44 pm

Vivi wrote: ↑

Sun May 05, 2019 1:51 am

It's kind of weird. The corrosion on the blade isn't as bad as I expected, but the liners are rusting abnormally fast. I wonder if the carbon steel blade is causing some sort of reaction, or if the liners are made out of a different material than they typically are?

I asked back in March and couldn't get a response (http://forum.spyderco.com/viewtopic.php?f=2&t=83235). Mine were not as bad as yours, just with black splotches. Still, I have no other Spyderco liners behaving like this with similar usage, even very old ones. I assume the P4 liners are some carbon steel.

Roland.

Interesting. I've rusted liners on other knives before, but never this fast. They do seem to be made of a different steel than usual.

After seeing all this I am thinking about sending my P4 off to get cerakoted. Just the internal parts. Liners, backlock and what not. Is this a viable solution? I am not so interested in getting the blade done as patina does not bother me. But would definitely consider getting it done as well. And a black blade on that P4 would look kickass.

marty_bill_ wrote: ↑

Thu May 09, 2019 2:38 am

After seeing all this I am thinking about sending my P4 off to get cerakoted. Just the internal parts. Liners, backlock and what not. Is this a viable solution? I am not so interested in getting the blade done as patina does not bother me. But would definitely consider getting it done as well. And a black blade on that P4 would look kickass.

Would that change the tolerances?

Albatross wrote: ↑

Thu May 09, 2019 8:52 am

marty_bill_ wrote: ↑

Thu May 09, 2019 2:38 am

After seeing all this I am thinking about sending my P4 off to get cerakoted. Just the internal parts. Liners, backlock and what not. Is this a viable solution? I am not so interested in getting the blade done as patina does not bother me. But would definitely consider getting it done as well. And a black blade on that P4 would look kickass.

Would that change the tolerances?

Possibly but they do it to guns all the time. And they have tight tolerances as well.

marty_bill_ wrote: ↑

Thu May 09, 2019 2:38 am

After seeing all this I am thinking about sending my P4 off to get cerakoted. Just the internal parts. Liners, backlock and what not. Is this a viable solution? I am not so interested in getting the blade done as patina does not bother me. But would definitely consider getting it done as well. And a black blade on that P4 would look kickass.

I am hoping that future K390 models are DLC coated. A DLC K390 Police LW with Navy FRN would be great!

steelcity16 wrote: ↑

Thu May 09, 2019 9:10 am

marty_bill_ wrote: ↑

Thu May 09, 2019 2:38 am

After seeing all this I am thinking about sending my P4 off to get cerakoted. Just the internal parts. Liners, backlock and what not. Is this a viable solution? I am not so interested in getting the blade done as patina does not bother me. But would definitely consider getting it done as well. And a black blade on that P4 would look kickass.

I am hoping that future K390 models are DLC coated. A DLC K390 Police LW with Navy FRN would be great!

Agreed. That would kickass. And probably sell really well. Guess we'll have to wait and see.

marty_bill_ wrote: ↑

Thu May 09, 2019 9:08 am

Albatross wrote: ↑

Thu May 09, 2019 8:52 am

marty_bill_ wrote: ↑

Thu May 09, 2019 2:38 am

After seeing all this I am thinking about sending my P4 off to get cerakoted. Just the internal parts. Liners, backlock and what not. Is this a viable solution? I am not so interested in getting the blade done as patina does not bother me. But would definitely consider getting it done as well. And a black blade on that P4 would look kickass.

Would that change the tolerances?

Possibly but they do it to guns all the time. And they have tight tolerances as well.

It would be worth trying.

Albatross wrote: ↑

Thu May 09, 2019 9:20 am

marty_bill_ wrote: ↑

Thu May 09, 2019 9:08 am

Albatross wrote: ↑

Thu May 09, 2019 8:52 am

marty_bill_ wrote: ↑

Thu May 09, 2019 2:38 am

After seeing all this I am thinking about sending my P4 off to get cerakoted. Just the internal parts. Liners, backlock and what not. Is this a viable solution? I am not so interested in getting the blade done as patina does not bother me. But would definitely consider getting it done as well. And a black blade on that P4 would look kickass.

Would that change the tolerances?

Possibly but they do it to guns all the time. And they have tight tolerances as well.

It would be worth trying.

Just sent an email off to Cerakote Nation about the knife and if it can be done. So we'll wait and see what they have to say.

I hope they do a DLC K390 run at some point. I really enjoy using the steel and would like to be able to carry it year round.

Vivi wrote: ↑

Thu May 09, 2019 7:03 pm

I hope they do a DLC K390 run at some point. I really enjoy using the steel and would like to be able to carry it year round.

+1! I know it is more work for Spyderco, but anything like the Rex45 sprint series and hopefully a K390 sprint series should have both satin and DLC as options. Its not like they won't sell out a bunch of DLC K390 PM2s, Para 3s, Natives, etc with Navy or Blurple G10 scales.

Vivi, in your experience have you found DLC an effective rust preventive on a carbon steel blade? I have no experience with either DLC or the more specific case of DLC over non-stainless steel.