Let's take a look inside my Police 4

[JRinFL]

You could try a firearm coating such as Duracote, Gun-Cote, or similar.

[The Mastiff]

I'm not convinced that coatings prevent corrosion. I think they do, in some cases, help, but Salt water and sweat can be caustic and find ways to infiltrate. Even humidity near a coast is always trying to eat your knife blade.

You have done a lot more testing than any of us and probably with more coatings than we know about so I'll take your advice. I was trying to think of a quick and dirty way to test for galvanic corrosion. To be quite honest I have never seen the issues that Vivi and some others have and I live in an area that can have me soaked through my shirts in 10 minutes outside spring through fall.

By the way Sal I noticed that for at least the last year the Spyderco's have been coming with less residual buffer grit and other gunk I used to clean off when I first took the knife out of the box to treat and then lube it prior to use. If there was anything that shouldn't be there I would probably have found it by now.

Joe

[vivi]

I'm not convinced that coatings prevent corrosion. I think they do, in some cases, help, but Salt water and sweat can be caustic and find ways to infiltrate. Even humidity near a coast is always trying to eat your knife blade.

sal

Sal, for me the DLC offerings have been a game changer.

I rust pretty much anything. I've rusted my Leatherman Micras real bad. I've rusted phones. I've rusted the hardware on a CTS204P Military within 24 hours.

My first experience with a DLC Spyderco was with a Para 2 DLC. The blade never rusted even though I carried it every summer IWB or in sweaty pockets. My sweat is so corrosive the liners, lock bar, hardware, stop pin were all coated in multiple mm of rust. I could scrape out big gobs of it with a toothpick. The blade never did rust.

So I then looked for a model with coated liners. The Manix XL fit the bill.

The XL DLC is the only Spyderco I have never rusted anywhere, aside from salts.

I have never seen a folding knife be capable of being carried year round with rusting unless its your H1 line. It has been a complete game changer for me.

If you're interested I could send you my Manix XL and Police 4. I don't know if there is anything you could gain from taking a look at them, but if you're interested the offer is there.

I know I'm the only one that feels this strongly about DLC in this context, but looking at the photos in this thread, having a non salt knife remain impervious to corrosion is a pretty big deal in my book. Offering a knife in DLC makes me a lot more likely to purchase a given model due to my experiences.

I know your experience and knowledge on the matter eclipses mine many times over, but for what it's worth, this has been my experience with the DLC models from your company.

[marty_bill_]

The P4 DLC job I had https://www.razoredgeknives.com/ do is completed! I don't have it in hand yet, but when I do I'll give you some shots of the liners.

[vivi]

oh man...that looks really good!

[VashHash]

That DLC coating came out really well.

[Ez556]

You could try a firearm coating such as Duracote, Gun-Cote, or similar.

Just as a data point from personal experience, Gun Kote is superior to Duracoat, but Cerakote is FAR superior to either (all professionally applied).

[vivi]

I was going to order a Police lightweight last night but I held off after seeing this update. I might send my G10 P4 in for the same treatment instead of buying a new knife. This would end up being my most carried knife if the DLC works as well for corrosion resistance as it does on my Manix XL.

[ZrowsN1s]

Ooh, that looks good!

[The Meat man]

Nicely done!

[vivi]

Well I finally got around to working on my Police 4 today.

I sanded all the parts down with 800 grit sandpaper and knocked off the rust, saving the liners for last since I knew they'd be the most work.

I roughed off the worst of the corrosion, focusing on the pockets of red rust and areas that appeared to be pitting. What I saw surprised me. It seems the liners had developed a patina in addition to the rust. I tried to capture it in photos and a short video:






https://streamable.com/fl16v


Convinced the liners are made of carbon steel, as I've never seen stainless liners behave this way, I got an idea. Why not force a patina with vinegar?

I tested out my theory by splashing the corner of a liner with white vinegar and waiting five minutes. Already saw a reaction similar to my A2 and 1095 knives.

I'm letting them soak for a few hours while I run errands. I'll post photos of how they look before I make any changes to them.

Excited to pocket the P4 again either way. I've missed this knife.

[JonLeBlanc]

That's really beautiful! One of the few coated blades I could actually get behind lol

[FK]

Carbon Steel Liners ????
Really happy I held off purchase of P4 in favor of the new PM2.

Regards,
FK

[vivi]

The 2 hour vinegar soak gave the liners a cloudy gray look:



I dropped the blade in with the liners for the first half hour and the liners reacted quicker than K390. Granted they don't have the same surface finish, but that still makes me wonder if they used some sort of carbon steel liner.

[marty_bill_]

Carbon Steel Liners ????
Really happy I held off purchase of P4 in favor of the new PM2.

Regards,
FK

I'm not trying to rain on your parade, but you are missing out on maybe the best knife in Spyderco lineup. And now with the LW Police no rust problem. I got the LW version as well and this thing kicksass!

[sal]

Hi Marty_bill,

Very nice.

When I design a knife more to please my own odd preferences, like the Shaman or the P4, I am finding that some you you have similar odd likes. I think it's because of the leaning more to function.

sal

[GarageBoy]

Why would it not be your typical 420 liners? So weird

[marty_bill_]

Hi Marty_bill,

Very nice.

When I design a knife more to please my own odd preferences, like the Shaman or the P4, I am finding that some you you have similar odd likes. I think it's because of the leaning more to function.

sal

Sal,
Yes, I've been through a pile of knives. And 1 always finds it's way back into my pocket. Yep, the P4. For whatever reason it just works. It works without fail.
Thanks,
Marty

[marty_bill_]

Well I got it back today and it was so worth it!

[Enactive]

Well I got it back today...

Wow that looks good. I don't usually like coated knives, but that backlock and H tho!

Holy smokes!

Presumably, he masked the lock interface?