CRK Sebenza 25 pivot & and orange juice

K

kwackster

Joined
Dec 23, 2005
Messages
2,049
The owner of this Sebenza 25 religiously eats an orange every day at breakfast; the fruit is cut with the knife into several parts, and afterwards the knife is rinsed under a hot tap.
Over time the orange juice slowly found it's way into the pivot, making the action sticky and the knife slow to open.
Last time the knife was opened was in the first week of March 2016, and today i opened it again.

This is how the S35VN blade surface looks after i cleaned off all the sticky gunk, first with a soft tootbrush and some dishwashing liquid, then with some nail polish remover, and finally in an ultrasonic cleaner (to get the last debri out of the pits)
Given enough time the citric acid in the orange juice clearly seems to damage the S35VN steel, and in some spots the pitting is deep enough to trap the point of a needle.
Pics can be clicked 2 x for a bit more detail.

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Some guys will claim there isn't a reason to take them down periodically for maintenance, saying just rinsing is fine. But you can see here there is a good reason why you should.

Thanks for sharing.
 
I know the pictures don't lie, I do the same, but, I rinse mine with hot water /dish soap daily when food prep is finished. I'll have to take mine down and see if it has avoided the pitting.
 
You can cut the orange and rinse the knife in such a way that no water or acid goes into that pivot, that should also be protected with some oil. Like cut it then wipe the knife. Rinse later quickly. Don't let water enter pivot
 
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Good pics. This is why i prefer to do all my food prep with my backup knife (spyderco pacific salt in H1 steel) there's something really comforting about a knife that won't suffer any corrosion, even if you aren't able to rinse her off or take it down.
 
that's some pretty good pitting.

Two solutions, as I see it:

1. Use a backup fruitknife like Mick suggested.
2. Use your CRK and keep it serviced up good-- pretty confident you'll arrive at the end of a long life <full of vitamin C, btw> with a well-loved Sebbie and not a pile of rust.
 
The juice from an orange is citric acid... an acid, and a blade that is continually exposed to it and not serviced certainly would pit. The damage is not rust, it is being etched by the acid. I would think almost any metal would have this issue including H1. Remember this is acid exposure, not rusting that is occurring.

Once you polish the area, I doubt the pitting will impact the action.

Hope all works out.
 
Iron City said:
The juice from an orange is citric acid... an acid, and a blade that is continually exposed to it and not serviced certainly would pit. The damage is not rust, it is being etched by the acid. I would think almost any metal would have this issue including H1. Remember this is acid exposure, not rusting that is occurring.

Once you polish the area, I doubt the pitting will impact the action.

Hope all works out.
Click to expand...

Very good points, but since i'm a little OCD (and for interesting info sake) i researched for a long time before buying the Pacific Salt in H1 as i planned to cut acidic fruits for lunch every day with it. It turns out from what ive found the citric acid shouldn't cause any issues on H1, these are the only chemicals that could cause an issue.

Halogens ( can eat the FRN handle)
HF= Hydrogen fluoride
HNO3 = nitric acid or aqua fortis
HCL = Hydrochloric acid or Hydrogen chloride in water (gastric acid)
H2O2 = Hydrogen peroxide
H2SO4 = Sulfuric acid
Or possibly Long chlorine exposure in an oxygen starved environment

Anyways, the sebbie would have no issue with fruit cutting, just need to remember to take her down for a good wd-40 clean after getting fruit juice in the pivot. Sebs love getting undressed anyway so no issues there :)
 
Wash it out good with hot, soapy water, dry thoroughly and then lube it. I use BreakFree. No pitting.
 
Question to the kwackster: Was there any damage or impact to the titanium? I suspect the stainless pivot hardware was affected similarly to the blade.
 
Mick_1KRR said:
Very good points, but since i'm a little OCD (and for interesting info sake) i researched for a long time before buying the Pacific Salt in H1 as i planned to cut acidic fruits for lunch every day with it. It turns out from what ive found the citric acid shouldn't cause any issues on H1, these are the only chemicals that could cause an issue.

Halogens ( can eat the FRN handle)
HF= Hydrogen fluoride
HNO3 = nitric acid or aqua fortis
HCL = Hydrochloric acid or Hydrogen chloride in water (gastric acid)
H2O2 = Hydrogen peroxide
H2SO4 = Sulfuric acid
Or possibly Long chlorine exposure in an oxygen starved environment

Anyways, the sebbie would have no issue with fruit cutting, just need to remember to take her down for a good wd-40 clean after getting fruit juice in the pivot. Sebs love getting undressed anyway so no issues there :)
Click to expand...

Solid response.

There are trade offs with pretty much any steel. I have an spyderco salt that I use for surf fishing and it has no rust and has done a nice job but in no way does it hold an edge like the steels used on the Sebenza.

Here is my surprising two cents. I don't necessarily need a super steel that can clean three deer without needing a touch up. I would rather have something that is easier to get back to razor sharp even if I have to do it more frequently.
 
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I am the "Husband of the Owner" of multiple restaurants and there too many food prep knives around for me to think about using any EDC knife for cutting food. I peel oranges and eat the sections. Unless it is a throw away knife or other tool, proper maintenance should be considered.
 
I've never understood the "food-prep with EDC" thing. I always use kitchen knives for that, and don't really care what happens to them.


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If folders are used for outdoor or away from home food prep, it makes sense to me. At home, I agree. Why not just use kitchen knives?
 
I do alot of fruit cutting with my edcs. So long as it is properly cleaned and rinsed, there shouldn't be any issues. Fruits that are acidic and have sap (such as jackfruit, banana, sugarcane, pineapple, oranges, durians to name a few) do stain if left to dry on the blade.
 
I always use a fixed blade for food prep unless absolutely necessary.
Much easier to clean, avoid cross contamination and forms a nice patina on my carbon blades.
 
Holy cow. Ive cut fruit for years with folders. Never seen such a thing. Makes for some awesome pictures though!
 
BellaBlades said:
Holy cow. Ive cut fruit for years with folders. Never seen such a thing. Makes for some awesome pictures though!
Click to expand...

I'm in the same boat. I cut fruit every day with my CRK, and sometimes can't do anything other than wipe it off due to lack of facilities. If I'm home, a quick rinse in the sink is all it might get. I'm about as far from OCD as a knife but can get. I've never experienced anything like this with S35VN. I've always felt it was exceptional in corrosion resistance.

A couple questions I have:

What lube were you using?
Were you running the pivot very loose....IE with a bit of a gap between the blade and washers?

This is really the first I've ever seen of any serious corrosion issues after a few years on this forum.
 
soak the blade in a rag saturated with WD-40 or kerosene, etc for a few hours and clean it up with some fine steel wool, wipe clean.... then oil the blade up with cooking oil and wipe dry... reassemble and apply some fluorinated grease to the pivots during assembly
 
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