Police 4 K390: Rusting Liners, and Rust

K390 is not a stainless steel. It will rust without proper care. There are a multitude of good protective lubricants out there, and as mentioned above, wax will do a good job, too. In the days before all of the high tech protective lubes, we used to wax our rifles before a hunt so that we need not fear rain or moisture ruining a beautiful blued finish. That said, my K390 gets used around food, so I use Vaseline, which is paraffin wax and mineral oil. It will even lube the pivot if you want. It stays on the blade unless you eat an apple with it, or wash it off. I have never had any issues and I live near the sea and jungle.
 
Frog Lube, Fluid Film....use a GOOD corrosion preventive. Ezox, Rig, Hornady One Shot, WD 40 speciality anti-corrosion are great too, but I wouldn’t use them if food prep was involved

Agreed; I use Frog lube on the blade and if I haven't taken down a knife for maintenance then I swab the liner areas with EEZOX. Below is one I bought from BFExchange last year and even though the original blade didn't have any rust, the insides were like you see below.

After cleaning up the liners/internals (plus a HAP40 blade swap) I coated them with EEZOX and put it back to work!

CFStretchSpa3_080918.jpg

CFStretchSpa5_080918.jpg

CFStretchSpa7_080918.jpg
 
My Spyderco knives don’t agree.
I mean, no that's not right. But hey whatever works for you.

Well per the Spyderco's website: Spyderco’s knives are assembled to exacting tolerances by trained technicians, so we discourage end users from disassembling or adjusting our knives.

If you don't believe Spyderco...

There's no need to ever "breakdown" a Spyderco except to satisfy the little boy inside who wants to tinker with mechanical things.

Soap, water, plus a brush, Qtip or toothpick and some paper towel, maybe WD40 and a good lube is all you need to maintain a Spyderco. Ask 'em.

If you want to treat a carbon steel like a stainless steel, then you need to oil a lot, even if you do take it apart.
 
Well per the Spyderco's website: Spyderco’s knives are assembled to exacting tolerances by trained technicians, so we discourage end users from disassembling or adjusting our knives.

If you don't believe Spyderco...

There's no need to ever "breakdown" a Spyderco except to satisfy the little boy inside who wants to tinker with mechanical things.

Soap, water, plus a brush, Qtip or toothpick and some paper towel, maybe WD40 and a good lube is all you need to maintain a Spyderco. Ask 'em.

If you want to treat a carbon steel like a stainless steel, then you need to oil a lot, even if you do take it apart.
Lol yea cause they don't want noobs taking them apart. And you can send them in and have them service them if you don't want too. But I have no issues with taking them down and getting them to go back correctly.
 
I have a novel thought...to each his own.

If you prefer to strip them down and conduct a thorough cleaning and maintenance, go for it...(taking into consideration your own ability and level of skill in regard to reassembly).

If you prefer to leave the knife intact, then perform your maintenance accordingly.

Easy peasy and nobody has to point fingers, be the only one who's right, nor get their panties in a twist.
 
Knives are not guns, they don't need to be disassembled to be cleaned or lubed. CRK knives being the exception, but Spydercos are designed to be maintained w/o disassembly.
I'm sure they don't need cleaning if you keep them in a case to look pretty in, partner.
 
There's no need to ever "breakdown" a Spyderco except to satisfy the little boy inside who wants to tinker with mechanical things.
I'm sure they don't need cleaning if you keep them in a case to look pretty in, partner.
It's no use Legs, some people just don't know what they don't know, and aren't willing to learn.
There's plenty of reasons to take a knife apart, besides cleaning.

I hope they make a ~3 inch version of the p4 with k390 blade and non stainless liners. If it wasn't a backlock, which doesn't lend itself well to chopping, I'd do it myself.
 
I'm sure they don't need cleaning if you keep them in a case to look pretty in, partner.

I use every knife I own "partner" including customs. I don't display knives in cases since I buy knives to use. I do have a machete hanging on the wall, due to its fancy sheath, but it gets taken down and used to cut weeds a few times a summer.

Sure to each his own, but Spyderco doesn't recommend disassembly and their knives are not designed for it. That's a fact not an opinion.

In contrast, Chris Reeve's knives are designed to be taken apart and come with lube and a wrench. I have a sebenza, it gets used, taken apart and cleaned (about every 12-18 months) per Chris Reeve's recommendations for their knives..
 
I live on the Pacific Ocean in a tropical country and I use my knives pretty hard. I don’t disassemble them for cleaning. Out of the 20-25 folders I own (all Spydercos) only a couple have ever been disassembled and that was mostly just for kicks. They are all in good working order and rust free and I suspect most if not all of them will outlast me. My regular folders get an occasional rinse, wipe down and lube if they get really messy and my salts just get a blast with the garden hose.

Disclaimer: I don’t have an opinion about how anybody else chooses to take care of their knives. Just thought I would share my personal experience.
 
I live on the Pacific Ocean in a tropical country and I use my knives pretty hard. I don’t disassemble them for cleaning. Out of the 20-25 folders I own (all Spydercos) only a couple have ever been disassembled and that was mostly just for kicks. They are all in good working order and rust free and I suspect most if not all of them will outlast me. My regular folders get an occasional rinse, wipe down and lube if they get really messy and my salts just get a blast with the garden hose.

Disclaimer: I don’t have an opinion about how anybody else chooses to take care of their knives. Just thought I would share my personal experience.
If you haven't looked between the scales and liners, in and around the pivot, backlock springs, etc, you don't know if they're rust free. I've stripped down a lot of tools that looked pristine on the outside, to find active corrosion underneath.
I agree rust doesn't mean for sure they'll quit working or die a premature death, but it's best to keep that stuff at a minimum if possible.

Rust never sleeps.

edit: Surfingringo Surfingringo
Do you just rinse and wipe down your other tackle, fishing reel, etc?
I always at least took my reels down after a saltwater outing, and occasionally during fresh water periods.
 
Last edited:
  • Like
Reactions: Mo2
I used to keep a Delica clipped to my board shorts while hiking the coastline to collect limpets, seaweed, and black crab. I wasn’t soaking in saltwater but the knife was exposed to sweat and salty air.

The VG 10 would spot rust each outing, and the metal liners had rusted enough after a year I replaced them. Before replacing, I would pull it apart and sand the liners and polish the blade. This worked for a while until I finally just replaced the liners.

I was not disappointed by this at all. In fact, I expected that was going to happen and was grateful I could tear the Delica down and maintain it.

Did this extend the life of the knife? Maybe? Was it necessary? I don’t know. I imagine even with all the corrosion the Delica would still work great. The OCD in me just wanted to clean it off.

The Salt series is FANTASTIC and obviously purpose built for this activity. Thanks Sal and crew for making these excellent water knives. I don’t see a need to tear these down at all.
 
I wonder how many hours/days/weeks it takes for a Delica or Police to dry out completely after a rinse or dunking...

This is one of the reasons why I prefer all titanium knives with an open back and no liners. They dry quickly inside and there is nowhere for moisture to collect and cause rust.

If a knife needs liners I think they should be highly corrosion resistant. I like to use and maintain the odd tool steel, but I do not care for rusty liners. I think Spyderco will do well to rethink the liner material on the Police.
 
Last edited:
I had another used Police Model come in this week. Looked fairly decent. I did the same treatment on the incoming knife and the daily carry first generation plain edge Endura.
1. get out the vinegar, a pair of pliers, cotton que-tips, disposable rag and tuf-glide.
2. press the que-tips flat with the pliers.
3. give the knife a good soaking with the vinegar and vinegar on the que-tips.
4. spray with tuf glide.

If knives come in looking really bad, I will take off the grips, if possible and soak in vinegar overnight, sand with multi thousand grit paper or 0000 steel wool. And go from there.

WD40 is a water displacer. I could use any silicon spray, mineral oil, olive oil, pam, 3 in 1 oil, and wipe off the excess.
Just remember, if you put something on the blade, and use the blade to cut some of your food that goes into your mouth, make sure it safe to eat that something!
 
Back
Top