Rusty M390?

Monofletch

Gold Member
Joined
Jan 14, 2010
Messages
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Is it common for M390 to surface rust after 3 days of carry? I know I am a sweaty mess delivering mail but enough for this?
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No this is not normal, I once had left m390 knife for day dirty after cutting onion(I am not proud of it :( but I had to leave in hurry) without any stains or rust on the blade.
 
Could be lots of things: iron/steel particles on the blade, poor finish (scratches are good for corrosion), maybe you exposed it to something unintentionally, maybe the blade wasn't heat treated or a very poor heat treat for some reason, etc.
 
Call Kershaw customer service and ask to have your knife inspected, and replaced if the blade steel is found to be faulty.
Their phone number is 800-325-2891
 
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You'd think M390 from ZT and Kershaw would behave basically the same. Doesn't appear to be the case here.
I think it's safe to assume, it's an impossibility that m390 from Kai will all behave the same. By it's nature, steel will vary in composition, heat treatment, contaminants, and more. Zero chance they'd have perfectly identical performance.


Makers like Don Hanson buy HUGE batches of steels so they can maintain the same attributes over long periods of time. Different w2 batches behave differently.


I guess what I'm saying is, variation is to be expected. Shit happens.
 
If you are not going to send it back, rub a scrunched up ball of aluminum foil on the rusty areas to remove as much as possible, then re-oil the knife.
 
Use some bar keepers friend and just clean it off.

If your worried more, use some edci or mineral oil.

Probably due to the surface finish more than anything.
 
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With all the knives that are being produced today using M390 and all the pics posted here, this is the first time I've seen any rust spots on M390. So, no, it's not common at all.
I guess it just goes to show that no stainless is impervious to rust.
 
My stonewashed Viper Fortis M390 hasn’t shown any signs of “corrosion” and I carried it in the peak of he summer. None of my Reates have rusted either.
 
With all the knives that are being produced today using M390 and all the pics posted here, this is the first time I've seen any rust spots on M390. So, no, it's not common at all.
I guess it just goes to show that no stainless is impervious to rust.
Its not the first. But it isn't that common. Mostly seen it on stonewashed or similar surfaces that allows moisture to pool.
 
I had a Gso 5.1 show similar “spotting” on the blade after a hike in wet conditions. A few spots were also under the scales. Some fine steel wool solved the problem. I was truly surprised though.
 
Have a look at a "TUF CLOTH" just rub the cloth on the blade and leave it to dry, it`s non-sticky, you can also get the marine version if you are going near salt water.
 
I just did 3 days of backpacking where I was pouring far more sweat than I ever thought possible (prolly need to talk to my doctor about it, just in case).

My Spyderco Para3 in M390 road shotgun in my pocket almost constantly with no issue. I was pretty impressed, actually. With as much salt water as it was exposed to, I wouldn’t have blamed anyone if it had gotten some rust spots.

So, I guess all that says is that, depending on how it is run M390 is capable of being exceedingly rust resistant.
 
In my experience all high carbon stainless can develop rust in small splotchy spots, especially on fresh surfaces that do not have a well developed oxide layer. If you passivate the steel by using cold gun bluing or even vinegar on a degreased blade it will give a slightly darker tint and prevent the splotchy rust spots. Steel always forms an oxide layer, that is how chromium stops corrosion in stainless. The beauty of stainless is that it forms a thin oxide layer that is very corrosion resistant and often very hard to discern.
 
Wow, that's crazy! :eek: Sorry to see that buddy. :( Let me know if you need me to be of any assistance.
 
I used my leather strop and black compound after I took the pic. Used the same oil to wipe it down. Nothing to report. I will let you know of any changes.
SpyderPhreak SpyderPhreak Thank you. I am good for now.
 
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