Patina or pitting?

D

Dirty_Dan

Joined
May 9, 2017
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61
Hey guys, I'd first like to start off by saying you guys are great! Your participation on this forum has made it an informative and fun source, it is my first place to go to when in doubt or am curious, you guys, indirectly, help me pick out my first Case knife.

Ok, so my dilemma is identifying the formation of patina or pitting. I have a Case chestnut bone medium stockman with cv blades (pictures will be posted below). I got cv with the intent of a patina forming over time through use, not through a "forced" procces. Though the first day I got it I tested the waters of a patina catylist, I cut one apple, after that some spots appeared on the blade. I know patina doesn't simply appear even and beautiful on the blades, but mine seems like distinctive dots and I do not want to go down the road of pitting/corrosion. That being said, I do not regularly oil my blades (if I do it is with forehead or nose oil) and it is a knife that I use and carry just about every chance I get, it is not a part of a collection.

Thank you for bearing with me in my post, if you guys need more/better pictures or info, let me know and I'll try my best. Additionally if this problem has already been addressed in another post, please let me know so I don't waste anybody's time. Thank you so much in advance!

Not sure if the pictures actually posted, still figuring it out, if not, hopefully this think works : https://www.flickr.com/photos/154755625@N07/with/34524351416/ . Please let me know if there are any issues, thanks.

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P.S. I love seeing pictures of your guys' knives, especially with patina, so I wouldn't be bummed out if you guys posted some...
 
First of all, welcome!
The spotting is odd, my experience with fruit cutting it that it leaves a fairly even patina like the one shown below on my apple cutting GEC 22. (With a finger print as an added bonus:))
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Hopefully someone with more experience can chime in, but your blade looks more "pepper spotted" than showing the start of a nice patina. Perhaps you should polish it off and start over?
About oiling- I never oil the blades but make sure I keep the pivots well lubed.
 
That looks like rust spots.

I have cut apples with Case CV blades and that has never happened to me. Procdure: Cut apple, eat apple, rinse blade off, dry, and return to pocket.

Example of a Case CV blade with apple patina (same knife in both pics, at different times)


 
Thank you for the quick responses, I too rinsed my blade off (wet paper towel) then made sure it was dry before dropping it in the pocket, I sure hope your eyes deceive you about it being rust....
 
So buff it off. Any decent metal polish will get you back to a shiny surface and you can try again with your patina.
 
Well, I tried to clean it off with lubricant and paper towel and slightly more abrasive dish scrub sponge, I was able to remove some of the spots, not quite all. I then cut up another apple, then cleaned and tried, after which there was a distinctive blue and beginning of patina- far different from last times results. I hope the few spots don't grow or hurt the blade. Thank you for your help. and if there are any others with input, it will gladly be received. Thanks!
 
I marvel that anyone can avoid rust on a carbon user without wiping the blade with (mineral) oil at least occasionally.
 
The spotting looks pretty familiar to me. My Case CV blades didn't take long to start showing a few spots on the otherwise polished CV finish. The spots seemed to develop with just some occasional pocket carry, in my own experiences with them, and more so in the more humid season where I live (July/August/September in NM).

I've since forced a patina on those same knives, using a 50/50 mix of vinegar and hot water (about 170-180°F), dipping the blades into the hot mix for a minute or three, until they're almost fully black. Some of that black rinses & wipes away, after which is left an even grey, durable oxide layer. That has helped minimize further spotting on them. The spotting on my knives was red rust; forcing a black oxide patina makes it a little more difficult for red rust to form in the first place. The steel will oxidize on it's own, one way or the other (red = destructive, black = non-destructive). Forcing a patina gets the oxide started on a less destructive path.


David
 
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It helps in a dry environment like Colorado, but using and stropping frequently does it for mine. Very mild patinas have built up over time, but they're not artistic. They represent the things and ways I cut.

Zieg
 
Your blade looks to me like it has a bit of surface rust which should polish out, and if it does leave a little pitting, won't be very visible once a good dark patina is established.
Dirty_Dan said:
That being said, I do not regularly oil my blades (if I do it is with forehead or nose oil) and it is a knife that I use and carry just about every chance I get, it is not a part of a collection.
Click to expand...
I do not recommend application of face-oil. It contains more salt than you think, which will encourage rust. Either keep the blade dry, or put a little mineral oil on it.
 
r8shell said:
I do not recommend application of face-oil. It contains more salt than you think, which will encourage rust.
Click to expand...

I never even though of that, that was most likely one of the contributing factors, thank you for the insight!

As for an update on the blade, after cleaning the blade and cutting an apple last night, the blade has turned more of a patina-gray and the rust spots are mostly gone. You guys are studs!
 
Do you live in a humid climate? Perspire due to activity or heat? That appears to be light rust forming from moisture. The salt from perspiration in the pocket can be harsh on steel.

Brush it lightly with mineral oil using a soft bronze gun cleaning brush. The spots will remain but the rust will be gone.

This is what steel does. It doesn't hurt anything, just relax and use the knife. It will age as it will with time and use.

When my blade is used for something messy I wipe it off, rinse it with hot water if possible. Maybe even soapy water if necessary. Then dry it, drop it in my pocket and go.

Once a month a small drop of oil in the joint and that's it.
 
I live in SoCal, fairly close to the beach, though not close enough for it to be a considerable factor. But I do whittle a lot and if its hot out my hand will perspire its fair share.
 
Welcome to the Porch, D Dirty_Dan It looks like a little surface rust and the begining of some pitting. I recommend cleaning it up with some Flitz or something like it. If you are going for a blue in your patina try using your blade to cut a nice juicy steak.
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Here are some other patina thread links for your viewing pleasure.
http://www.bladeforums.com/threads/show-your-patina-forced-earned-or-accidental.1154841/
This one is a good one for how to force a patina
http://www.bladeforums.com/threads/get-a-deep-even-black-patina-on-1095-carbon-steel.928315/
 
Looks like some pitting, not a proper patina. +1 on Flitz paste. One other thought... make sure the blade is completely dry before folding it back. If you don't the unexposed half of the blade can oxidize. I leave the blade open for a few mins. or else make sure to wipe with a second, dry towel. I also lightly coat blades with Hoppes #9 oil.
 
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