Spyderco Forums

We found that galvanic corrosion pops up in places not expected. We're still experimenting. Material, heat treat, other metals in close proximity or touching. All areas in question.

Hey Vivi, I've been carrying the new FRN / VG-10 model in Hawaii for about a week with no issues.

sal

captnvegtble wrote: ↑

Sat Sep 14, 2019 2:16 pm

Correct. So not only does Spyderco tell us they're stainless steel liners, but we also know that K390 is a more expensive steel upgrade... so a business wouldn't intentionally use a more expensive corrosion prone steel for handle construction without any benefit.

So you believe Spyderco's collateral more than Vivi's pictures ? Vivi's report is by far not the only one. Why would P4 liners rust, and P3 liners not, in the same environment ? Vivi, how's your P3 doing ?

I have many lined Spyderco, including 20+ year old ones, and most get used in the same, relatively dry (compared to Vivi's) environment. I've had lined Spydercos with rusted tang (Cruwear, Hap40), but clean liners. My P4 copies (all 3) are my only Spyderco with very noticeably rusting liners. Somewhere here is a thread where I asked Sal about the steel used in the P4 liners and he didn't want to answer. You can search for it.

Galvanic corrosion ? Between G10 and liners ? Or on the other side touching nothing ? Corrosion in my knives (and Vivi's) occurs on both sides of the liners. What steel are the liners made of, Sal, and are they coated ?

sal wrote: ↑

Sun Sep 15, 2019 12:01 am

We found that galvanic corrosion pops up in places not expected. We're still experimenting. Material, heat treat, other metals in close proximity or touching. All areas in question.

Hey Vivi, I've been carrying the new FRN / VG-10 model in Hawaii for about a week with no issues.

sal

Thanks Sal!

That's good to hear you're researching the issue.

I've personally never really had any issues with VG10/FRN knives and corrosion. Maybe really mild rust inside the nested scales after long use - I'm talking years - but very minimal, and usually wipes off clean with a strop.

sal wrote: ↑

Sun Sep 15, 2019 12:01 am

We found that galvanic corrosion pops up in places not expected. We're still experimenting. Material, heat treat, other metals in close proximity or touching. All areas in question.

Hey Vivi, I've been carrying the new FRN / VG-10 model in Hawaii for about a week with no issues.

sal

I'm taking a road trip this month and I'll be passing by one of the best knife shops in the country. If they have one in stock I plan to buy one and put it straight in my pocket.

The Police 4 is my favorite design of yours, but the materials in the LW version will suit me better.

ferider wrote: ↑

Sun Sep 15, 2019 12:34 am

captnvegtble wrote: ↑

Sat Sep 14, 2019 2:16 pm

Correct. So not only does Spyderco tell us they're stainless steel liners, but we also know that K390 is a more expensive steel upgrade... so a business wouldn't intentionally use a more expensive corrosion prone steel for handle construction without any benefit.

So you believe Spyderco's collateral more than Vivi's pictures ? Vivi's report is by far not the only one. Why would P4 liners rust, and P3 liners not, in the same environment ? Vivi, how's your P3 doing ?

I have many lined Spyderco, including 20+ year old ones, and most get used in the same, relatively dry (compared to Vivi's) environment. I've had lined Spydercos with rusted tang (Cruwear, Hap40), but clean liners. My P4 copies (all 3) are my only Spyderco with very noticeably rusting liners. Somewhere here is a thread where I asked Sal about the steel used in the P4 liners and he didn't want to answer. You can search for it.

Galvanic corrosion ? Between G10 and liners ? Or on the other side touching nothing ? Corrosion in my knives (and Vivi's) occurs on both sides of the liners. What steel are the liners made of, Sal, and are they coated ?

My Police 3 also gets rusty liners, but it took years rather than 6 months. It also wasn't as bad. Since I rarely carry my P3 let me go a head and pop it open for a comparison shot.

This Police 3 was purchased the year they came out...2008 I think? I carried it in rotation with other knives over the years. Took it apart every few years to sand out rust, and as a result the liners are a little more polished than a stock P3 or P4.

Unlike the P4, this is a knife I've always carried year round. The P4 is a knife I got knowing I couldn't carry it half the year.









Bit worse than expected.

For the record the purpose of this thread is to document my experience rather than complain. I know that I can rust any pocket knife that isn't a salt, and frankly rusting a salt someday wouldn't surprise me. That's why I carry a Pacific Salt or DLC Manix XL during the warmer seasons.

In fact, let this thread be a testament to the DLC Manix. I have never seen a speck of corrosion anywhere on that knife. It's the only non-salt Spyderco I can say that about. I've rusted other DLC spydercos because the liners weren't coated.

Hey Vivi.
Did Spyderco contact you and offered you a job as a ,,rust-tester“? I think you would be a great candidate for this job. You will get a knife and you will try to rust it during summer :D

I'll sub in for that role. Sweat and salt air is a nasty combo!

Also, the only requirement for galvanic corrosion is not physical contact, but electrical contact. That means even metal separated by non conducting material like G10 or Teflon can still be electrically coupled via a film of conducting fluid such as sweat.

Vivi, have you tried coating the liners with anything? Froglube, Balistol or whatever?

That is somewhat surprising to see, but as others have noted stainless isn’t rustproof by any means (as you well know).

Hey Vivi, I hate unexpected surprises in carbon steel folders so I pull them apart before use and coat blade, liners, stop pin ... with Eezox.

Might be worth a try mate. :)

:)

Bloke wrote: ↑

Sun Sep 15, 2019 4:29 pm

Hey Vivi, I hate unexpected surprises in carbon steel folders so I pull them apart before use and coat blade, liners, stop pin ... with Eezox.

Might be worth a try mate. :)

how does eezox work for you? always good to get a firsthand account.

Vivi wrote: ↑

Sun Sep 15, 2019 2:50 am

My Police 3 also gets rusty liners, but it took years rather than 6 months. It also wasn't as bad. Since I rarely carry my P3 let me go a head and pop it open for a comparison shot.

This Police 3 was purchased the year they came out...2008 I think? I carried it in rotation with other knives over the years. Took it apart every few years to sand out rust, and as a result the liners are a little more polished than a stock P3 or P4.

Thanks for sharing, Vivi.

Informative thread. Thanks guys!

curlyhairedboy wrote: ↑

Tue Sep 17, 2019 6:28 am

Bloke wrote: ↑

Sun Sep 15, 2019 4:29 pm

Hey Vivi, I hate unexpected surprises in carbon steel folders so I pull them apart before use and coat blade, liners, stop pin ... with Eezox.

Might be worth a try mate. :)

how does eezox work for you? always good to get a firsthand account.

Hey Curly, I stumbled on Eezox while looking for a dry lube to use on my Rock Chucker reloading press about fifteen odd years ago. It leaves a bit to be desired as far as lubes go but to date has been an excellent rust inhibitor. I used it on guns, knives, tools, nuts and bolts etc. on vehicles, kids bikes, scooters and anything else I want to protect from corrosion and can’t fault it.

It’s inexpensive and a small tin should last you years and for what it’s worth when my Province arrives I’ll take the scales off and give it a coat of Eezox too. :)

Vivi wrote: ↑

Sat Sep 14, 2019 7:13 pm

James Y wrote: ↑

Sat Sep 14, 2019 6:45 pm

I rusted the liners on my Police 3 in VG10, but that took me 3-4 years of year round carry, and the rust was about 30% of what happened with the Police 4. Don't recall any rust on the blade, backspacer or lock bar on the P3.

I knew the blade on the P4 would require more attention, but I did not expect the same of the liners.

Vivi, looking at your pics of the Police 4 (K 390): Sure, a lot of rust on the liners, not doubt.
But, and correct me if I am wrong: Does that really matter speaking strictly functional?
And how many years would you have to carry the knife without ever cleaning off the rust till it WOULD get a real problem functionwise?

These are honest questions, since I personally never had any serious rust problems whatsoever on my folders, despite carrying them a lot in sweaty pockets and sometimes over days in wet conditions (mostly VG10 though). So I have no real experience here.
Might be, that your enviroment (the air) is a lot more salty than where I live (next salt water around 200 miles away I guess and winds coming from there shielded off by hight mountains)

Bloke wrote: ↑

Wed Sep 18, 2019 1:18 am

curlyhairedboy wrote: ↑

Tue Sep 17, 2019 6:28 am

Bloke wrote: ↑

Sun Sep 15, 2019 4:29 pm

Hey Vivi, I hate unexpected surprises in carbon steel folders so I pull them apart before use and coat blade, liners, stop pin ... with Eezox.

Might be worth a try mate. :)

how does eezox work for you? always good to get a firsthand account.

Hey Curly, I stumbled on Eezox while looking for a dry lube to use on my Rock Chucker reloading press about fifteen odd years ago. It leaves a bit to be desired as far as lubes go but to date has been an excellent rust inhibitor. I used it on guns, knives, tools, nuts and bolts etc. on vehicles, kids bikes, scooters and anything else I want to protect from corrosion and can’t fault it.

It’s inexpensive and a small tin should last you years and for what it’s worth when my Province arrives I’ll take the scales off and give it a coat of Eezox too. :)

Thanks! :)

curlyhairedboy wrote: ↑

Sun Sep 15, 2019 7:29 am

Also, the only requirement for galvanic corrosion is not physical contact, but electrical contact. That means even metal separated by non conducting material like G10 or Teflon can still be electrically coupled via a film of conducting fluid such as sweat.

Right, that's really interesting. So technically, while gripping the knife in your hand, with the liners and backspring exposed like that, you're closing a weak electrical circuit?

I wonder if it has an appreciable effect on any galvanic corrosion?

Cambertree wrote: ↑

Wed Sep 18, 2019 5:20 am

curlyhairedboy wrote: ↑

Sun Sep 15, 2019 7:29 am

Also, the only requirement for galvanic corrosion is not physical contact, but electrical contact. That means even metal separated by non conducting material like G10 or Teflon can still be electrically coupled via a film of conducting fluid such as sweat.

Right, that's really interesting. So technically, while gripping the knife in your hand, with the liners and backspring exposed like that, you're closing a weak electrical circuit?

I wonder if it has an appreciable effect on any galvanic corrosion?

potentially closing one, yeah. it's why outdoor steel usually gets a coating of zinc (galvanized steel). the manufacturer knows the steel is going to want to rust, so it puts a layer of zinc on there. When wet, the galvanic coupling causes the zinc to corrode instead of the steel.

curlyhairedboy wrote: ↑

Wed Sep 18, 2019 6:21 am

potentially closing one, yeah. it's why outdoor steel usually gets a coating of zinc (galvanized steel). the manufacturer knows the steel is going to want to rust, so it puts a layer of zinc on there. When wet, the galvanic coupling causes the zinc to corrode instead of the steel.

Thanks Curly, that’s very interesting and new to me.

So a knife with nested liners in a non conductive handle material like G10, plus recessed screws, and a titanium clip, would potentially mitigate or minimise this effect?

It’d be fascinating to know if that galvanic effect, combined with dried salt buildup from sweat and conductive moisture actually contributes in a measurable way to liner corrosion.

Some days ago I disassemble my Chief and there was some very minor corrosion on the backspacer. And that is linerless G10 and my screws are locktited.....

Corrosion is a bit weird. Last year I made an experiment with my students and we had nails in different environments. The biggest surprised was a nail that corroded in distilled water. Did not expect that for sure.