This might be a dumb question. So far, I've only had patinas from cutting food, which is okay I guess, I'm wondering if just exposure to oxygen makes the steel patina or is it the oil on your fingers from being handled that makes it darken? What makes a knife patina over time?
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What makes a natural patina?
- Thread starter irona
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"On metal, patina is a coating of various chemical compounds such as oxides, carbonates, sulfides, or sulfates formed on the surface during exposure to atmospheric elements (oxygen, rain, acid rain, carbon dioxide, sulfur-bearing compounds), a common example of which is rust which forms on iron or steel when exposed to oxygen. Patina also refers to accumulated changes in surface texture and colour that result from normal use of an object such as a coin or a piece of furniture over time"
Unless you've a controlled temperature/humidity climate/mineral oil or rex wax covering it in which your knives reside patina would naturally form from the atmosphere surrounding it even if it was sitting at rest.
During use the oils from your hand certainly come into play. If you open your carbon steel knife by pinching it open in the same manner day in and day out over time you'll see a darker area than the rest of the surrounding. The spine of my opinel, the part that protrudes out of the wooden handle has darken considerably over time due to being exposed and through carry in my pocket/repeated opening.
Unless you've a controlled temperature/humidity climate/mineral oil or rex wax covering it in which your knives reside patina would naturally form from the atmosphere surrounding it even if it was sitting at rest.
During use the oils from your hand certainly come into play. If you open your carbon steel knife by pinching it open in the same manner day in and day out over time you'll see a darker area than the rest of the surrounding. The spine of my opinel, the part that protrudes out of the wooden handle has darken considerably over time due to being exposed and through carry in my pocket/repeated opening.
afishhunter
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Acidic foods. Apples, Oranges, lemons, limes, etc. I've heard potato will cause a patina somewhat, too.
Right, but I'm talking more about non-foods. Thanks though!
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I've gotten a patina from tape and other adhesives on boxes. To me, a natural patina is just one that comes from real use rather than being forced. I use my knives for food prep and eating quite often.
Railsplitter
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I'm curious about this too. I usually carry stainless knives but sometimes I'll carry a carbon blade. I don't use my pocket knives to cut food. I really only cut dry things with them. Because of these two factors I've never had a natural patina form on my carbon blades. I guess I just don't carry them long enough.
Still curious though. I've seen old knives with pitting that were obviously carried and used for a long time that still have a bit of the original shine on the blades but none, or very little, of the discoloration that I would call a patina. I assume those knives were only used for dry materials but that's only an assumption.
Still curious though. I've seen old knives with pitting that were obviously carried and used for a long time that still have a bit of the original shine on the blades but none, or very little, of the discoloration that I would call a patina. I assume those knives were only used for dry materials but that's only an assumption.
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I have a Schrade Uncle Henry 897UH with stainless blades and carbon springs that I carried for about 20 years. The blades have no patina (obviously), but the springs have a very healthy patina. Just time in the pocket and use in the hand. It will happen over time.
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"patina" is a romantic description of oxidation. For marketing purposes it sounds better than "corrosion" or "rust".
The vast majority of old knives that are shiny have been resurfaced with abrasives. Knives with original crocus or glazed finishes are fluffed and buffed if they have a dot of oxidation on them since the people with the most money to spend want shiny knives and either don't care about original finish or don't recognize the difference. Original finish is so uncommon, a lot of new collectors might not have ever seen original finish.
Condition doesn't necessarily indicate use. I've seen completely unused knives that were stored poorly and were severely damaged by rust.
The vast majority of old knives that are shiny have been resurfaced with abrasives. Knives with original crocus or glazed finishes are fluffed and buffed if they have a dot of oxidation on them since the people with the most money to spend want shiny knives and either don't care about original finish or don't recognize the difference. Original finish is so uncommon, a lot of new collectors might not have ever seen original finish.
Condition doesn't necessarily indicate use. I've seen completely unused knives that were stored poorly and were severely damaged by rust.
An oxidizer (or oxidizing agent or oxidant) is a chemical that receives electrons from another substance and oxidizes it. It could be oxygen itself, acids (including those in skin oils), or any of a number of other chemicals. They all receive electrons and will oxidize the unbound iron in steel. If the steel is bound with, say, chromium, it will not readily oxidize.
Iron has two common oxides:
Fe2O3 which is red rust. The oxide is bigger than the iron matrix it forms in, which is why it crumbles and breaks out of that matrix. There's not room for it.
Fe3O4, which we call patina and forms on the surface. The "good" oxide if you like it, and most but not all the honk it protects the steel underneath from rust.
Iron has two common oxides:
Fe2O3 which is red rust. The oxide is bigger than the iron matrix it forms in, which is why it crumbles and breaks out of that matrix. There's not room for it.
Fe3O4, which we call patina and forms on the surface. The "good" oxide if you like it, and most but not all the honk it protects the steel underneath from rust.
Old Hunter
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I bought this Kabar 1081 Medium Stockman new at a base exchange in December 1998; it went into my pocket right there. The next month it accompanied me to the V Corps winter exercises in Germany, then the NTC at Fort Irwin CA in JUL/AUG 2000, and to OIF in 2003. I retired it in 2005 when I retired from the ARNG (it now sits with my other military mementos). The knife was new when I got it, it was carried everyday, and it cut everything I needed to cut - from MRE's to opening an anti-freeze container. I remember the anti-freeze incident because it blued the forward half of the main blade (hard to tell in this picture) which amazed me at the time. Every mark on the knife is "natural" - nothing was forced - guess that is how natural patina forms. OH
Ps I didn't become a knife collector until about 2009, never carried one knife exclusively since, many will never patina like this one (well, most now are stainless).
Ps I didn't become a knife collector until about 2009, never carried one knife exclusively since, many will never patina like this one (well, most now are stainless).
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How does patina form? Just through time and use. Pick a knife and just carry it every day. If you're always changing the knife you carry it'll take years of time to look like some of the old timers you see here. Just use it and don't worry about what it looks like. The steel will react to it's environment however it wishes - allow it to and over time it'll darken and take on that aged look you see in old knives. The patina rarely looks even as it grows, it's mottled and changes with time. Over a long time it grows to a more even darkness.
My 77 Barlow has turned nearly black in the areas exposed to perspiration in the pocket. This knife has had a solid year of pocket time 18 hours a day every day. It's used for everything from food to opening boxes, etc etc. It lives in my front pocket. It's in my pocket every waking moment of the day.
The blade of course is exposed to assorted food prep but the spine never has been exposed to anything food related. The spine's coloring has formed just from exposure in the pocket to perspiration and general handling in use. It's as black as the scales themselves (the liners are nickel silver). I've not helped along any part of the process with this knife, I've just carried it and used it.
You'll notice the blade is very dark where exposed outside the handle. It's lighter and less patina'd where it rests within the handle. I'm assuming it's probably perspiration that does this. I actually don't perspire heavily and I live in the high desert, so it's very dry here - humidity has no part in this knife's aging process (you have to try hard to get things to rust here). In summary I've done nothing to speed or retard the patina. I've just used it for the tasks I needed it for. I don't really cut much fruit or potatoes with it, though I have used it to a limited extent on such things. If messy I rinse it off or wipe it down, but I don't abuse it nor baby it. I've completely let is do it's own thing. The dark areas are a very dark gray - almost black. Spots appear and disappear over time also.
My 77 Barlow has turned nearly black in the areas exposed to perspiration in the pocket. This knife has had a solid year of pocket time 18 hours a day every day. It's used for everything from food to opening boxes, etc etc. It lives in my front pocket. It's in my pocket every waking moment of the day.
The blade of course is exposed to assorted food prep but the spine never has been exposed to anything food related. The spine's coloring has formed just from exposure in the pocket to perspiration and general handling in use. It's as black as the scales themselves (the liners are nickel silver). I've not helped along any part of the process with this knife, I've just carried it and used it.
You'll notice the blade is very dark where exposed outside the handle. It's lighter and less patina'd where it rests within the handle. I'm assuming it's probably perspiration that does this. I actually don't perspire heavily and I live in the high desert, so it's very dry here - humidity has no part in this knife's aging process (you have to try hard to get things to rust here). In summary I've done nothing to speed or retard the patina. I've just used it for the tasks I needed it for. I don't really cut much fruit or potatoes with it, though I have used it to a limited extent on such things. If messy I rinse it off or wipe it down, but I don't abuse it nor baby it. I've completely let is do it's own thing. The dark areas are a very dark gray - almost black. Spots appear and disappear over time also.
How does patina form? Just through time and use. Pick a knife and just carry it every day. If you're always changing the knife you carry it'll take years of time to look like some of the old timers you see here. Just use it and don't worry about what it looks like. The steel will react to it's environment however it wishes - allow it to and over time it'll darken and take on that aged look you see in old knives. The patina rarely looks even as it grows, it's mottled and changes with time. Over a long time it grows to a more even darkness.
My 77 Barlow has turned nearly black in the areas exposed to perspiration in the pocket. This knife has had a solid year of pocket time 18 hours a day every day. It's used for everything from food to opening boxes, etc etc. It lives in my front pocket. It's in my pocket every waking moment of the day.
The blade of course is exposed to assorted food prep but the spine never has been exposed to anything food related. The spine's coloring has formed just from exposure in the pocket to perspiration and general handling in use. It's as black as the scales themselves (the liners are nickel silver). I've not helped along any part of the process with this knife, I've just carried it and used it.
You'll notice the blade is very dark where exposed outside the handle. It's lighter and less patina'd where it rests within the handle. I'm assuming it's probably perspiration that does this. I actually don't perspire heavily and I live in the high desert, so it's very dry here - humidity has no part in this knife's aging process (you have to try hard to get things to rust here). In summary I've done nothing to speed or retard the patina. I've just used it for the tasks I needed it for. I don't really cut much fruit or potatoes with it, though I have used it to a limited extent on such things. If messy I rinse it off or wipe it down, but I don't abuse it nor baby it. I've completely let is do it's own thing. The dark areas are a very dark gray - almost black. Spots appear and disappear over time also.
Gorgeous knife! Thanks for sharing and for the advice.
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For me, I think there are three types of patina. 1: Natural (slow, varied, and unique). And happens to be my favorite, if you have the patience. Always unique and more natural style IMO
2: Artificially Accelerated (can be quality and good looking). 3: And Artificially Accelerated (Fugly). And yet, even though I have my preferences, (the good, the bad, and the ugly), they are still only my personally preferences.
I tried one on an Spyder Ambitious 8cr13mov (supposedly stainless I thought?). It came out pretty ugly in my opinion. [emoji51] But I was also attempting to stonewash and prep for some file work.
When I patina pure silver for shelf props, I boil a couple eggs, then drop the two in a baggie for a few days, and get some pretty amazing color. Blues, yellows, green, purples, etc. But on my knives, I'm very hesitant to try anything for risk of that "ugly" outcome. I guess I'm just paranoid to end up with garbage I'm sure I have the ability.
I think my favorite forced patina of all time was done by one our own. Was on a Millie, and I think he said he used mustard, and bubble wrap. Turned out beautifully.
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2: Artificially Accelerated (can be quality and good looking). 3: And Artificially Accelerated (Fugly). And yet, even though I have my preferences, (the good, the bad, and the ugly), they are still only my personally preferences.
I tried one on an Spyder Ambitious 8cr13mov (supposedly stainless I thought?). It came out pretty ugly in my opinion. [emoji51] But I was also attempting to stonewash and prep for some file work.
When I patina pure silver for shelf props, I boil a couple eggs, then drop the two in a baggie for a few days, and get some pretty amazing color. Blues, yellows, green, purples, etc. But on my knives, I'm very hesitant to try anything for risk of that "ugly" outcome. I guess I'm just paranoid to end up with garbage I'm sure I have the ability.
I think my favorite forced patina of all time was done by one our own. Was on a Millie, and I think he said he used mustard, and bubble wrap. Turned out beautifully.
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Condition does not indicate age either. Old knives don't always look old. I picked up a 30 year old Queen Winchester in 1095 steel at a gun show with a perfect mirror finish. It had never been used or buffed. More than a few purveyors at my local gun shows have vintage knives and they are in as found condition, including $1K+ Remingtons. I lust after an original Remington banana trapper every time I go, it's in good but unbuffed condition.
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I agree. As BRL says, condition is only a sign of condition.
I picked up a 30 year old Queen Winchester in 1095 steel at a gun show with a perfect mirror finish. It had never been used or buffed. More than a few purveyors at my local gun shows have vintage knives and they are in as found condition, including $1K+ Remingtons. I lust after an original Remington banana trapper every time I go, it's in good but unbuffed condition.
Since when are Queen Winchester knives considered old??
I must be getting old. I have seen lots of old (really old) knives that are in original condition. They're squirreled away in collections mostly. I've seen far more knives that were fluffed and buffed and described as mint... sometimes they're described as mint even before the buffing wheel stopped spinning.
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A lot of plant materials that are encountered on my outings will actually cause patina. I notice that carving certain woods will leave a distinct patina.
A natural patina is just the summation of all the little things. Food is a big contributor, but not the only one.
A natural patina is just the summation of all the little things. Food is a big contributor, but not the only one.
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How does patina form? Just through time and use. Pick a knife and just carry it every day. If you're always changing the knife you carry it'll take years of time to look like some of the old timers you see here. Just use it and don't worry about what it looks like. The steel will react to it's environment however it wishes - allow it to and over time it'll darken and take on that aged look you see in old knives. The patina rarely looks even as it grows, it's mottled and changes with time. Over a long time it grows to a more even darkness.
My 77 Barlow has turned nearly black in the areas exposed to perspiration in the pocket. This knife has had a solid year of pocket time 18 hours a day every day. It's used for everything from food to opening boxes, etc etc. It lives in my front pocket. It's in my pocket every waking moment of the day.
The blade of course is exposed to assorted food prep but the spine never has been exposed to anything food related. The spine's coloring has formed just from exposure in the pocket to perspiration and general handling in use. It's as black as the scales themselves (the liners are nickel silver). I've not helped along any part of the process with this knife, I've just carried it and used it.
You'll notice the blade is very dark where exposed outside the handle. It's lighter and less patina'd where it rests within the handle. I'm assuming it's probably perspiration that does this. I actually don't perspire heavily and I live in the high desert, so it's very dry here - humidity has no part in this knife's aging process (you have to try hard to get things to rust here). In summary I've done nothing to speed or retard the patina. I've just used it for the tasks I needed it for. I don't really cut much fruit or potatoes with it, though I have used it to a limited extent on such things. If messy I rinse it off or wipe it down, but I don't abuse it nor baby it. I've completely let is do it's own thing. The dark areas are a very dark gray - almost black. Spots appear and disappear over time also.
look at that contrast! its sooo coool! thats why I want that steel used as covers! im always referencing this knife