Pretty impressed with the corrosion resistance of my Sebenza

M

Muaddib1116

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Dec 26, 2010
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So a few weekends ago, I went sailing for the weekend and dumped my pocket in a different spot than usual on a little shelf below a porthole. We sailed for six or so hours that Saturday afternoon, and got a bit of spray through the porthole, which coated my small Insingo pretty well. Before we bunked down on our mooring, I just wiped a the bulk of the sea water residue off the handles and blade. A few amber-ish spots had formed on the blade, but they wiped off fairly easily, some scraping with my thumbnail got the stubborn ones off. The next day had a similar return trip. Before I closed up the boat and left, I just stuck it under the faucet and opened and closed it a few times to rinse everything out. Since then, it's been sitting unused.

Today I took it out of my storage case to use. It was a little stiff opening at first, but after cycling it a few times it loosened up and smoothed out. I found a small faint amber spot on the tip of the blade that I rubbed off with my thumbnail. I put a dab of Finish Line Extreme Fluoro (which I have been very pleased with) on the detent ball, and this thing is as smooth and tight as it's ever been. I haven't opened it up to inspect what damage it might have done to the washers or pivot bushing, but I suspect that the tight tolerances and grease probably did a good job of keeping the evil out, considering it was just spray, not a dunking.

I just have to say I'm impressed. I'm impressed with the S35VN steel's corrosion resistance, and I'm impressed with the Finish Line grease, and I'm impressed with CRK. This experience, plus the shop tour videos I just watched, has enhanced my already fond and loving impression of CRK. I seriously heart these knives (as the kids say).
 
I would agree, I have spent time actually in the sea with a CRK folder on several occasions and always had a similar experience to yours (S30V though). A splash of fresh water and a drying is all it needs. They hold up very well to the humidity and sweaty pocket carry they see on land here as well. :D:thumbup:
 
So I have an update to my Small Insingo. I grabbed my Small Seb today and noticed how much less resistance the blade had to moving than my Insingo. I didn't remember this disparity, so despite the Insingo pivoting smoothly, albeit with resistance, I inspected the action more closely and could determine that the small lock-side washer was stuck to the blade and spinning against the scale. I decided a dissection and cleaning was in order.

There was some hidden corrosion, but not too much. The stop pin and standoff barrel nuts both had a slight ring of rust near their flange, easily rubbed off with a paper towel. Surprisingly, the pivot barrel nut had no corrosion. Unsurprisingly, the lock-side washer had a good deal of corrosion. It took some good rubbing and a bit of knuckle-grease to clean it and the corresponding blade tang area of rust. As far as I could determine, it was corrosion of the washer, not the blade steel. A good cleaning, re-greasing, and assembly has the knife back to how it should be. Glassy smooth with just the right amount of hot-knife-through-butter resistance.

It was interesting that there was corrosion on one washer and not the other, and I'm not really sure why. Perhaps there was not quite enough grease to repel the sea water the way that the other washer did, I don't know. It is impressive how smooth the blade was, even with the washer stuck to the blade and sliding against the titanium scale. I suppose the lesson is, that even though no permanent damage was done, it's still best practice to disassemble and clean a knife after exposure to salt water.
 
One of Chris' properties when working with Crucible to create S30V and then S35VN was the anti-corrosion factor of the steel.
 
Muaddib1116 said:
So I have an update to my Small Insingo. I grabbed my Small Seb today and noticed how much less resistance the blade had to moving than my Insingo. I didn't remember this disparity, so despite the Insingo pivoting smoothly, albeit with resistance, I inspected the action more closely and could determine that the small lock-side washer was stuck to the blade and spinning against the scale. I decided a dissection and cleaning was in order.

There was some hidden corrosion, but not too much. The stop pin and standoff barrel nuts both had a slight ring of rust near their flange, easily rubbed off with a paper towel. Surprisingly, the pivot barrel nut had no corrosion. Unsurprisingly, the lock-side washer had a good deal of corrosion. It took some good rubbing and a bit of knuckle-grease to clean it and the corresponding blade tang area of rust. As far as I could determine, it was corrosion of the washer, not the blade steel. A good cleaning, re-greasing, and assembly has the knife back to how it should be. Glassy smooth with just the right amount of hot-knife-through-butter resistance.

It was interesting that there was corrosion on one washer and not the other, and I'm not really sure why. Perhaps there was not quite enough grease to repel the sea water the way that the other washer did, I don't know. It is impressive how smooth the blade was, even with the washer stuck to the blade and sliding against the titanium scale. I suppose the lesson is, that even though no permanent damage was done, it's still best practice to disassemble and clean a knife after exposure to salt water.
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It makes sense that the copper washer would be the first to succumb to corrosion as copper is a pretty active metal. I've not exposed mine to seawater (haven't sailed in over a decade) but it has been coated in engine oil, antifreeze and just about every other auto-related fluid along with lots of freshwater (I leave it in my pocket when I wade wet) without any issues at all.

S35VM steel is relatively corrosion resistant
Knife-steel-chart-3.jpg

And 6AI4V titanium is highly resistant as well.
 
The name kind of gives things away there. :D Phosphor bronze is an alloy of copper, tin and phosphorus. (I'm not sure of the % for each metal). That alloy makes for a strong, tough, non sparking, fine grain material that has low corrosion and friction. That is of course great for washers as well as a number of other industrial applications. :):thumbup:
 
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