I'm Thinking Stretch in Super Blue - Good Choice??

[awa54]

Very carefully, I bent it back toward the other way when open with my bare hands until the centering was better. I've since tried this with some VG10 folders and could not get them to budge so at least in my experience it seems that the clad knives are just that much softer.

You really shouldn't be able to bend a knife blade by hand!

Does this imply that the 420 cladding was somehow left in an unhardened state? Is that even possible? I don't know that much about the finer details of heat treatment, especially for stainless steels, but it was my impression that using a softer *attainable hardness* steel like 420J1 was done so that when the laminate blade was heat treated the cladding hardness would remain substantially lower than the core hardness in order that the blade could both be *very* hard at the cutting edge *and* springy/resilient due to the properties of the cladding steel (which ideally would fall in a hardness range to be spring tempered, *not* unhardened).

Maybe the heat treatment for the Blue Super is such that the 420 is either not hardened fully, or its temper is drawn too low by the required time/temp for the Blue steel core? I'd be very surprised if this was the case, any knife maker capable of producing such excellent knives as Spyderco (and their makers outside of the US) would have undoubtedly worked out all such details before finalizing the blade metallurgy and have chosen a different cladding if the heat treatment was incompatible, after all this is hardly their first laminate blade! (however the data sheets I found conflicted a bit, some saying oil quench was possible, others indicating that 420J1 is air hardening only... Blue is almost certainly water/oil quench).

[jackknifeh]

Very carefully, I bent it back toward the other way when open with my bare hands until the centering was better. I've since tried this with some VG10 folders and could not get them to budge so at least in my experience it seems that the clad knives are just that much softer.

You really shouldn't be able to bend a knife blade by hand!

I know almost nothing about it but bending a knife blade is something Murray Carter talks about on one of his videos. Most of his stuff will be about his knives I think but some has got to be universal. Anyway, his blades are all laminated with Hitachi white steel and ss on the sides like the Stretch (except the Stretch is SB). If I remember correctly the blade can bend slightly but, and this is the important part, they should return to the straight position. I'll try to find the video later where he talks about this. I may not be entirely accurate. I have to go right now and can't look but maybe you can (or anyone). I think the subject is about testing a knife he gets back from a customer who thinks something may be wrong. He talks about testing the knife blade for problems like bending, chipping at the edge, etc. He uses a bic lighter to press the side of the edge against it to see if it bends slightly off line and then returns straight without chipping at the apex. I need to watch it again because my memory may not be accurate.

Jack

[awa54]

My Stretch SB feels like a totally normal hardened and tempered blade; rigid enough that it takes serious pressure to deflect the blade with my fingers, and springy enough to return to true after flexure.

...and after a full progression from coarse diamond plate through J-nat finish stone it's *fantastically* sharp!

I did have the blade drag issue with the FRN handle scales touching the blade, but corrected it by removing the scales and carefully sanding the edges (just where they overlap the blade tang) down to be flush with the steel liners. My example had two washers on one side of the blade and one on the other, so when I reassembled it I removed the extra, the blade now has a hairs breadth of clearance between the tang and liners on both sides, centers perfectly when closed and opens/closes very smoothly.

What a great knife!

Now if only there was a "mini-stretch" ...yeah, I know, it's called a Delica :P

[jackknifeh]

Very carefully, I bent it back toward the other way when open with my bare hands until the centering was better. I've since tried this with some VG10 folders and could not get them to budge so at least in my experience it seems that the clad knives are just that much softer.

You really shouldn't be able to bend a knife blade by hand!

I know almost nothing about it but bending a knife blade is something Murray Carter talks about on one of his videos. Most of his stuff will be about his knives I think but some has got to be universal. Anyway, his blades are all laminated with Hitachi white steel and ss on the sides like the Stretch (except the Stretch is SB). If I remember correctly the blade can bend slightly but, and this is the important part, they should return to the straight position. I'll try to find the video later where he talks about this. I may not be entirely accurate.

Jack

I found the Carter video I mentioned. I didn't remember it exactly like I thought. He wasn't talking about a blade bending then returning to it's original straightness. He was talking about the edge flexing a bit then returning to it's original position, straight. The video is actually about why edges chip. Is the blade faulty or was it pushed beyond it's intended capabilities? I watched it again and the first thing I wanted to do is test an edge on one of my knives. Then I thought, what if it chips? :eek: :mad: What if it just stays bent? :eek: :mad: Will Spyderco take my word that based on my understanding (lack of actually) and testing knowledge assume the blade was faulty and replace it??? I doubt it too. They'll do their own testing and probably give me a quote for repairing the knife or simply sharpening out the chip. They may even add a little to the cost hoping to prevent me from doing something so stupid again. :) Just for a bit of fun I am going to do this to a cheap kitchen knife. We have plenty of those. :)

Anyway, here's the link. This is off subject of the thread so I apologize. I do enjoy most of Mr. Carter's videos.
https://youtu.be/dU3ALY8OmZk" onclick="window.open(this.href);return false;

Jack

[awa54]

I found the Carter video I mentioned. I didn't remember it exactly like I thought. He wasn't talking about a blade bending then returning to it's original straightness. He was talking about the edge flexing a bit then returning to it's original position, straight. The video is actually about why edges chip. Is the blade faulty or was it pushed beyond it's intended capabilities? I watched it again and the first thing I wanted to do is test an edge on one of my knives. Then I thought, what if it chips? :eek: :mad: What if it just stays bent? :eek: :mad: Will Spyderco take my word that based on my understanding (lack of actually) and testing knowledge assume the blade was faulty and replace it??? I doubt it too. They'll do their own testing and probably give me a quote for repairing the knife or simply sharpening out the chip. They may even add a little to the cost hoping to prevent me from doing something so stupid again. :) Just for a bit of fun I am going to do this to a cheap kitchen knife. We have plenty of those. :)

Anyway, here's the link. This is off subject of the thread so I apologize. I do enjoy most of Mr. Carter's videos.
https://youtu.be/dU3ALY8OmZk" onclick="window.open(this.href);return false;

Jack

I am assuming that Murray Carter was discussing Japanese double bevel kitchen knives ground very thin at the edge like a nakiri (haven't watched the vid yet...). For a knife like that which is essentially just one step thicker at the edge than a straight razor (no kidding!) it's easy to get edge deflection with just pressure from the back of a fingernail against the side of the blade edge. My Yamawaku santoku and gyuto are both ground to a fine enough edge that I can see and feel the deflection when sharpening them on the coarser stones, the edges are hardened to the low 60s Rockwell, but still retain amazing resilience (the knives I have are V2 steel edges).

I did however unintentionally destruction test the gyuto early on in my ownership of it; I attempted to slice a baguette with it and the hard crust put a nasty ripple in the sharpened bevel! It did *not* cause any cracking though and I was able to rectify the problem by taking the final bevel back by just a fraction of a millimeter. There's a reason bread knives are moderate hardness serrated blades!

All my blue steel Japanese kitchen knives are the basic Japan Woodworker models, great steel, nice patterns, but nowhere near the finish grind of a higher end Japanese knife (or a Murray Carter knife). All of them have heavy enough edge geometry that they would probably chip out before deflecting.

** After watching the video, it was just what I thought! This sort of test is not practical with a heavy edge like most multi-purpose folding knives have. The Stretch SB would probably chip before you could see the flex with the naked eye, but it would take a whole lot more force than what Carter was exerting to produce the chips he showed. Just think of a double edge razor blade versus a single edge (or utility knife) blade, they are the same steel, but DEs are very flexible, while an SE blade is more rigid and thus will snap after only a small amount of deflection.

[awa54]

Just for a bit of fun I am going to do this to a cheap kitchen knife. We have plenty of those. :)
Jack

Typical low hardness stainless steel kitchen knife blades will likely just wind up with a bend in the edge, most cheapie kitchen knives also have too thick of an edge grind for that test to work. Carter's blades are very high carbon non-stainless edge steel hardened to the low to mid 60s Rockwell.

My traditionally forged Japanese kitchen knives make my Global and Wusthof blades feel like unhardened butter knives by comparison, but if I don't treat them with utmost respect they *will* rust or break!

[jackknifeh]

Just for a bit of fun I am going to do this to a cheap kitchen knife. We have plenty of those. :)
Jack

Typical low hardness stainless steel kitchen knife blades will likely just wind up with a bend in the edge, most cheapie kitchen knives also have too thick of an edge grind for that test to work. Carter's blades are very high carbon non-stainless edge steel hardened to the low to mid 60s Rockwell.

My traditionally forged Japanese kitchen knives make my Global and Wusthof blades feel like unhardened butter knives by comparison, but if I don't treat them with utmost respect they *will* rust or break!

After thinking about it for about 2 seconds I'm sure you are right about that test with the lighter only being worth anything on knives with a very thin blade. I hadn't thought about that. On our cheapie kitchen knives I have thinned the edge so they do cut better than when the edge angles are higher. I hadn't done this test yet so I just got up and using an ink pen I pressed the side of the edge on a Victorinox paring knife. I have several of these. They were about $6 each on CKTG I think. I put a much lower edge angle on them when I got them and they do a good job. We also just throw them in the dishwasher if we want to. If the edge gets dinged or dulled I just sharpen it. Anyway, as I pressed the side of the edge on the pen I could see it flex by watching the reflection on the edge bevel. When I lifted the knife the edge went back to it's straight position. There is no bend in the reflection as I move the knife and watch the reflection of light move along the edge. So I guess the steel on that knife (some kind of stainless) is hardened properly. They do hold an edge pretty good but all they ever cut is vegetables and stuff like that. I'm sure the edges are damaged more by how the knives are treated. Tossing in the sink, dishwasher, etc. I don't toss them in the sink but wife does sometimes. I've seen her just drop a knife on the counter instead of just laying it down. She has always resisted me getting better kitchen knives because she didn't want to worry about taking care of better quality, more expensive knives. Cut something, drop the knife on the counter not paying attention to if it lands on the edge or not, drop into sink or dishwasher, etc. If it gets dull she knows I'll sharpen it. She admitted she was just too lazy to properly care for a nice knife. I gave in to her desire about this until a few months ago. I got 3 Spyderco knives then the Kuro-uchi Carter. She immediately fell in love with the Spyderco's and asked if we should get more of them. Same with the Carter knife. She still uses the other knives and tosses them in the sink, etc. But the Carter and Spyderco knives she treats them completely differently. When dirty the Spyderco's (being a stainless steel) lay on the counter until they get hand washed. The Kuro-uchi, being a carbon steel she wipes off and dries after using it.

I wonder how Murray Carter and other makers of high-end kitchen cutlery check their knives prior to selling. Do they do this edge bending test? I was thinking Mr. Carter only does it when a customer sends back a knife after the edge chips. He would then test the steel to determine if he feels the steel wasn't heat treated or quenched or whatever properly of if he feels the edge was pushed beyond what it was designed for. Maybe he does some testing on every knife he makes. I don't know. I'm very pleased with the Carter knives I have. Also the Spyderco's. I've only bought Spyderco folders in the past few years I think. I did get some other manufacturer's knives but none have the consistent quality and when needed, customer support Spyderco provides. I haven't bought a Spyderco fixed blade until I got the Mule 20 knife recently. I'm making a handle for it now but it's very slow going. This summer I've actually been very busy doing other stuff. I only sit down with the Mule for a few minutes at a time it seems. I have the handle on the knife and it just lacks shaping and finishing. I need to get back on that knife and get it finished. I'll get a sheath made and use it. I'm really looking forward to it.

Just to get back on subject I tried the test on my SB Stretch. The edge didn't flex at all. Even with the edge being thinner than when it was new. Here's a picture of how the edge is now. You can see the patina and also the bevel where I sharpened it. But the bevel is convex and still has some thickness behind the edge apex that the paring knives nor the Carter Kuro-uchi has.



I did get the nerve to push the edge of the Kuro-uchi on the pen just now. It did flex and then go back to it's original position. I didn't need to push very hard for it to flex. But the Stretch SB blade didn't flex at all. Maybe I need to thin it some. You know what? I think I will. I just compared it to my Carter neck knife. The Carter is considerably thinner. I know I will NEVER use the Stretch as a hard use folder so I think I'm going to really thin the edge. I'll measure the thickness now and after and state the thickness at the top of the edge bevel. I'll also measure the Carter the same way just for comparison. I don't carry the Stretch very often but I love the knife. I had the blue FRN/ZDP Stretch and sold it because I didn't carry it. I've sold a few knives simply because I didn't carry them and then regretted it. That's how it was with the ZDP Stretch.

Gonna start thinning the SB Stretch blade. Not the entire blade but I'm going to remove a bunch of steel from at least the portion of the SB you can see. I'll take measurements before and after and post pictures when I 'm done.

Jack

[awa54]

The edge on that Stretch looks fantastic! What stone progression did you use to get there?

I think I'll leave my SB Stretch close to stock, I already lowered the total included angle of the edge, but didn't work the thinner bevel far up the blade, so it cuts nicely, but doesn't look all that different from the factory edge.

As far as extremely accomplished bladesmiths like Carter, I'd imagine that he has worked out the process of forging, hardening and tempering to a finely tuned state. If he does everything as usual the result will be close enough to ensure exceptional performance. Also in the shaping and final sharpening stages he can probably feel how the steel is reacting on the stones to the point of being able to discern a blade that is under or over hardened. My experience at the forge is very limited and I have nothing approaching mastery of any step in that craft, however even a newbie like me can get a fair amount of information back from the blade during the working and finishing process (I have used "easy" carbon steels and the blades I made are not "high performance" in any way).

[jackknifeh]

The edge on that Stretch looks fantastic! What stone progression did you use to get there?

I think I'll leave my SB Stretch close to stock, I already lowered the total included angle of the edge, but didn't work the thinner bevel far up the blade, so it cuts nicely, but doesn't look all that different from the factory edge.

As far as extremely accomplished bladesmiths like Carter, I'd imagine that he has worked out the process of forging, hardening and tempering to a finely tuned state. If he does everything as usual the result will be close enough to ensure exceptional performance. Also in the shaping and final sharpening stages he can probably feel how the steel is reacting on the stones to the point of being able to discern a blade that is under or over hardened. My experience at the forge is very limited and I have nothing approaching mastery of any step in that craft, however even a newbie like me can get a fair amount of information back from the blade during the working and finishing process (I have used "easy" carbon steels and the blades I made are not "high performance" in any way).

Thank you awa54. To reprofile I have DMT and Shapton glass stones to choose from. I'm sure for the Stretch I would have chosen the Shapton glass. DMT stones are great but for a knife I really care about I will always use the Shaptons. Even at the coarser grits the scratch pattern is much more consistent and shallower. But they cut very fast. If I used every stone I would have used the 320, 500, 1k, 2k, 4k and 8k. But, I probably skipped every other stone during the progression. They work just fine when skipping a stone grit. I got the Shapton stones one or two at a time and started with a 320, 1k, 4k and 8k as my set. These 4 stones do perfectly well in a progression. I got the others over time just because I wanted them. And for some reason I feel a set of stones without a 2k just seems like something is missing. I'd have to say I use it as a single stone for quick touchups when using the Shaptons. But more times than not for a quick touch up I use the Spyderco fine. I may have finished the stretch with the Spyderco UF. When it comes to a "last stone" when dealing with the higher grits I'm never dissatisfied with the UF. Great stone. I even use it for straight razors which need a very smooth edge (not toothy) to provide a comfortable shave. I have 3 type stones. Spyderco fine and UF. DMT XC-EF. and Shapton glass in the grits I mentioned plus a 16k which I seldom use for knives.

I'm done with what I decided to do with the Stretch. I finished it about an hour ago. I had stone washed the blade a while back and as I was working on lowering the edge bevel angle I accidentally scratched the stonewash. So I decided to thin the entire blade enough to remove the stonewash. To do that I went through every Shapton glass starting with the 500 thru the 8k.


Here is a picture of it now. The edge bevel looks the same. The only obvious change is I can't feel a quick change in angle when I slide my finger down the blade (spine to edge). The surface is a very smooth transition from flat grind to slightly convex edge bevel. Hope that made sense. But the blade now has no stonewash nor does it have either Spyderco logo's on the sides. The last grit I used was the Shapton glass 8k. I have always noticed it's harder to get the flat surface as polished as the edge bevel when using the same stone. If I want to put a mirror finish on the side of a blade it will be easier to do it with a strop. In this picture you can see the patina has been removed.


In this picture I try to show the level of polish on the different portions of the blade. The edge bevel is polished pretty well. The exposed SB is polished some and the 420-J1 is considerably more stratched still. I assume that is because it is much softer and whatever grit is used will cut just a tad deeper than it does on the harder SB core steel. May be right or wrong about that. :confused: :)


Before I started this I measured the thickness of the blade at the top of the edge bevel along the blade. It measured between .5 and .6mm in different spots from heel to tip. Now some places are aroune .4mm. What I did was thin the blade to get rid of the stonewash. That means the blade isn't much thinner. I also lowered the edge angle some. It's hard to tell all this from a photo but I can feel a difference in the thickness when I pinch the blade between my thumb and middle finger at the spine and slide them down toward the edge and off the blade. If any cutting performance is better it will be because the blade is thinner around the top of the edge bevel. I don't think I lowered the edge apex angle very much. Maybe some but it would have been a natural result from lowering the entire edge angle. I didn't put a micro-bevel on the edge this time. Not intentionally anyway. The actual apex angle is created by whatever inconsistency there is in my control as I stroke the stone.

I'm going to EDC the Stretch starting tomorrow and I'm going to use it for every cutting task I come across unless there is some reason to use something else. The Stretch, even with the edge from the box is an extremely good slicer. Now mine is much thinner right at the edge and very sharp. Right now if I use the sharpness test where you lay the pad or skin of your thumb on the edge and slide it sideways it feels like the edge apex reaches out to grab the skin. I'm eager to see about the edge retention under constant use cutting no telling what I will need to cut. I have always loved the Stretch but never used it consistently like I plan to now.

Jack

[awa54]

Hi jackknifeh,

that's some nice work! Do the Shapton stones really remove stock that fast, or are you just amazingly patient? I go from a 150 Naniwa to 1k "red brick", 2k "green brick" then a Rika 5k, and finish with either a strop loaded with yellow stone, or a Japan woodworker natural finish stone depending on the blade. I also have an Amakusa natural, a random intermediate finish stone from 330mate and a small uchigomori. The heavy lifting of big stock removal is usually tasked to a diamond plate; I have a coarse DMTdiasharp and a fine Eze-lap, the diasharp doubles as a stone flattener. When I really need to cheat there's always the belt sander :O

As far as polishing a bevel that isn't perfectly flat, the "green brick" (Naniwa 2k) is a magic worker for getting most of the way there... just mud it up and roll the blade a bit as you work the flat and you'll get an improbably even semi-gloss finish (the Suehiro 5k leaves a more matte finish than this 2k). I have a love-hate relationship with the green brick, because it's so soft that I can only use it with an edge trailing stroke, but it *does* polish and remove a burr incredibly well.

How long did you have to wait for your Carter knives? Last I looked he didn't have any stock of Japanese pattern kitchen cutlery, but that was quite a while ago...

** just went to his web site, great looking wares, but the pricing has changed since way back when! Stock has as well though, if you have the funds it looks like there are plenty of amazing blades to choose from. Guess I'll stick to Spyderco stuff to satisfy my blade lust for a bit longer

[jackknifeh]

Hi jackknifeh,

that's some nice work! Do the Shapton stones really remove stock that fast, or are you just amazingly patient? I go from a 150 Naniwa to 1k "red brick", 2k "green brick" then a Rika 5k, and finish with either a strop loaded with yellow stone, or a Japan woodworker natural finish stone depending on the blade. I also have an Amakusa natural, a random intermediate finish stone from 330mate and a small uchigomori. The heavy lifting of big stock removal is usually tasked to a diamond plate; I have a coarse DMTdiasharp and a fine Eze-lap, the diasharp doubles as a stone flattener. When I really need to cheat there's always the belt sander :O

As far as polishing a bevel that isn't perfectly flat, the "green brick" (Naniwa 2k) is a magic worker for getting most of the way there... just mud it up and roll the blade a bit as you work the flat and you'll get an improbably even semi-gloss finish (the Suehiro 5k leaves a more matte finish than this 2k). I have a love-hate relationship with the green brick, because it's so soft that I can only use it with an edge trailing stroke, but it *does* polish and remove a burr incredibly well.

How long did you have to wait for your Carter knives? Last I looked he didn't have any stock of Japanese pattern kitchen cutlery, but that was quite a while ago...

** just went to his web site, great looking wares, but the pricing has changed since way back when! Stock has as well though, if you have the funds it looks like there are plenty of amazing blades to choose from. Guess I'll stick to Spyderco stuff to satisfy my blade lust for a bit longer

Most of my life I only had two sharpening stones. A med. and a fine Arkansas. I didn't know much about caring for them. I'd use oil and when done I'd wipe the oil off and put them away. I never cleaned or flattened them at all. Never even heard of that. Therefore they had gotten so clogged I'm sure they didn't work as fast as they should. After learning more about sharpening stones on forums and such when I did get new ones I chose the stones the experienced guys praised. Therefore I don't have experience with different water stones to compare the Shapton glass to. I am very happy with how fast they cut though. But to compare their speed to other stones all I can do is trust what the more experienced guys say. One of the significant comments I kept seeing was how fast they cut compared to other stones of like type. It did take a while to get used to using them to the point I could get super sharp edges. I could use the Shapton's to get the edge very sharp and polish the bevel if I wanted but I couldn't get the super crisp edge that I could using either the Spyderco or DMT stones. This was frustrating for quite a while. Then 3 or 4 months ago I re-profiled a knife and was surprised that when I was done with the Shaptons the edge was sharper than I usually had been getting without the Spyderco fine and/or UF. Now I can get the edge super super (for me) sharp using only the Shapton glass stones. I'm assuming I needed more time on those stones to develop the feel of them. Some people think I'm nut's but IMO to get the really crisp edge on a knife you need to be able to "feel" it. I can "feel" it. It's a lot more than just holding the knife at the proper angle and stroking it back and forth trying to maintain a consistent angle and a given amount of pressure. That's the mechanics of sharpening and can be explained and taught and learned. I have no scientific data or knowledge to explain the "feel". Anyway, I think the "feel" took a long time for me with the Shapton glass. For some reason I didn't have any problem getting the "feel" when I first got the Spyderco stones. They just worked as well as they do now when I first got them. There was no learning curve (for me) in regards to learning the ceramic type stone. The DMT either. I don't have any idea why (maybe it's psycological) I couldnt' get the results with the Shaptons at first that I could with others. But whenever I was finished with the Shaptons I'd always finish up with the Spydercos. I've almost bought Naniwa stones a time or two but never did. Everyone loves them that have used them.

The neck knives I ordered came within a few days after ordering them. The kitchen knife took about 3 weeks I think because they had to make it. The kitchen Kuro-uchi was a free knife from an offer to get it along with the purchase of Carter neck knife. They have the Muteki (apprentice made) neck knives and kitchen knives also I think. Based on using my Muteki and original neck knives I can't tell any difference in the two when it comes to edge retention. If I get any more Carter kitchen cutlery I'd definitely try the Muteki knives. What made me want a Carter knife for EDC to begin with was I really wanted to see how the hand forged blade steel performs. Normally for EDC I have stayed away from fixed blades. Now that I've gotten used to it I actually like a fixed blade for the simple reason is you don't need to worry about stressing the pivot or a lock failing under hard use. Having said that I have never had any problems with any Spyderco being used as hard as I might use a knife. But for EDC I still think a folder is the best option for several reasons. I got the Spyderco summer catalog in the mail yesterday. I noticed there are a few fixed blades available now that I've not seen before. Even a little neck knife with H1 blade steel.

I used my re-profiled Stretch quite a bit yesterday. I had to cut a little schrubbery away and the Stretch cut through it like butter. The blade being thin cut right through small wooden branches on bushes very easily. There was no twisting needed at all like I sometimes do. I didn't cut with it all day but I did use it more than I normally use a knife. I didn't notice any sharpness loss during the day. I sliced some phone book paper last night and it hadn't lost any significant sharpness at all. A knife that can still perform perfectly under normal use even after it has lost the sharpness required to slice into the edge of a piece of phone book paper. After cutting into the edge of the paper I continue slicing using the entire edge to see if I can feel any little chips in the edge. In this case the Stretch SB did a fair amount of cutting and didn't loose even enough of the shaving sharpness it had. No measurements were taken to explain how much sharpness loss there was but I was very impressed with the performance of the Stretch and the SB steel. I'm also very happy for this thread because it prompted me to get the Stretch out again and play with it. Gotta say I'm even more happy with it now than I was. I'm basing that on the performance of the SB sharpened at a pretty low angle. I'm going to carry and use it for a while to see if yesterday's performance can be expected all the time or was it just luck. I'm basing my opinion now on the cutting the knife did and the fact that the steel didn't even loose any of the crisp sharpness. Edges can loose the shaving (arm hair) sharpness but still retain a very sharp working edge. The SB stretch didn't even loose the arm hair shaving sharpness. SUMMARY: superblue is good. That's the official answer. :)

Jack

[Knutty]

Well I've got to change my answer (you know, the one no one noticed and everyone forgot). SB is now on my "junk steel" list. Oh, I know it's great if you prefer wiping and cleaning your blades rather than using them, but for me, it's crap.

And yeah, I know what I'm about to describe isn't "light use," but I don't care.

I've been carrying my SB Stretch a lot lately, for reasons I won't bore you with. I used it to cut the seal off a gallon jug of muriatic acid, and that's when things started to fall apart.

That's all I did... Use the very tip of the blade to cut off the seal. I didn't dip the blade in the acid, let it sit for a few hours, then giggle myself silly. But after the first time, the tip turned to crap. Not rust, really, just sort of like a combination of brass and a turd.

Then, because my knives serve me rather than the reverse, I did it again. Same thing; just the seal. And I did rinse/wipe it off immediately afterward. But this time, the ENTIRE SB portion of the blade turned the copper/turd color. It went all the way through to the back of the blade, so that looking at the spine, you could easily tell where the SB was and where the soft outer layer of the steel whose name I forget is.

But I don't always carry the SB Stretch. I also carry my 2015 forum knife, the S90V Native 5. Yes, I used that one to open a jug of muriatic acid. My knives serve me. And did the S90V cry like a little b**ch? No, it did not. You can't even tell it's been used.

Also used a VG-10 Endura for the same ... this one is between the other two. A bit discolored, but nothing to cry about.

Yeah, I know why this happened to the SB. I know it's not a stainless, and I know you need to pamper it. My point is that it's a crap steel UNLESS you want to spend more time pampering it than using it.

[dubya3]

Well I've got to change my answer (you know, the one no one noticed and everyone forgot). SB is now on my "junk steel" list. Oh, I know it's great if you prefer wiping and cleaning your blades rather than using them, but for me, it's crap.

And yeah, I know what I'm about to describe isn't "light use," but I don't care.

I've been carrying my SB Stretch a lot lately, for reasons I won't bore you with. I used it to cut the seal off a gallon jug of muriatic acid, and that's when things started to fall apart.

That's all I did... Use the very tip of the blade to cut off the seal. I didn't dip the blade in the acid, let it sit for a few hours, then giggle myself silly. But after the first time, the tip turned to crap. Not rust, really, just sort of like a combination of brass and a turd.

Then, because my knives serve me rather than the reverse, I did it again. Same thing; just the seal. And I did rinse/wipe it off immediately afterward. But this time, the ENTIRE SB portion of the blade turned the copper/turd color. It went all the way through to the back of the blade, so that looking at the spine, you could easily tell where the SB was and where the soft outer layer of the steel whose name I forget is.

But I don't always carry the SB Stretch. I also carry my 2015 forum knife, the S90V Native 5. Yes, I used that one to open a jug of muriatic acid. My knives serve me. And did the S90V cry like a little b**ch? No, it did not. You can't even tell it's been used.

Also used a VG-10 Endura for the same ... this one is between the other two. A bit discolored, but nothing to cry about.

Yeah, I know why this happened to the SB. I know it's not a stainless, and I know you need to pamper it. My point is that it's a crap steel UNLESS you want to spend more time pampering it than using it.

It's junk steel because it got a patina easily?!? I suppose if all you judge a steel by is how stainless it is and looks then yes, I guess it's crap steel

[bearfacedkiller]

I don't spend any time pampering my Super Blue. I don't use it to open jugs of acid though. Mine have seen tons of food prep and some use cleaning fish and game and I have no issues yet. They have a dark patina but no rust. Everybody has different needs when it comes to corrosion resistance and for my uses in my very dry climate carbon steels work fine. Corrosion resistance is fairly far down on my list of qualities I like in steels.

You should try a tuff cloth or similar if you are having problems.

[jackknifeh]

Well I've got to change my answer (you know, the one no one noticed and everyone forgot). SB is now on my "junk steel" list. Oh, I know it's great if you prefer wiping and cleaning your blades rather than using them, but for me, it's crap.

And yeah, I know what I'm about to describe isn't "light use," but I don't care.

I've been carrying my SB Stretch a lot lately, for reasons I won't bore you with. I used it to cut the seal off a gallon jug of muriatic acid, and that's when things started to fall apart.

That's all I did... Use the very tip of the blade to cut off the seal. I didn't dip the blade in the acid, let it sit for a few hours, then giggle myself silly. But after the first time, the tip turned to crap. Not rust, really, just sort of like a combination of brass and a turd.

Then, because my knives serve me rather than the reverse, I did it again. Same thing; just the seal. And I did rinse/wipe it off immediately afterward. But this time, the ENTIRE SB portion of the blade turned the copper/turd color. It went all the way through to the back of the blade, so that looking at the spine, you could easily tell where the SB was and where the soft outer layer of the steel whose name I forget is.

But I don't always carry the SB Stretch. I also carry my 2015 forum knife, the S90V Native 5. Yes, I used that one to open a jug of muriatic acid. My knives serve me. And did the S90V cry like a little b**ch? No, it did not. You can't even tell it's been used.

Also used a VG-10 Endura for the same ... this one is between the other two. A bit discolored, but nothing to cry about.

Yeah, I know why this happened to the SB. I know it's not a stainless, and I know you need to pamper it. My point is that it's a crap steel UNLESS you want to spend more time pampering it than using it.

The area of the SB you are complaining about, is it just a matter color difference? Is the steel's ability to take an edge and hold it changed in that spot? That is what I'd worry about. For me personally, a non-stainless steel changing color is just a characteristic of the steel. But when it comes to things we care about we all have our quirks or pet peeves. I don't care if the tip of my blade is centered perfectly when it is closed. But I can't stand blade play when it's open and locked. For some others it's just the opposite or something else bugs them. Can you tell us if the steel's performance ability is reduced?

About the Tuf-cloth or Tuf-glide I don't feel as strongly about it as I used to. Not the right thread to go into details but I've come to think it's not the SUPER anti-corrosion product I used to think it was. One small detail. Using it on M4 I couldn't even force a patina on the steel until after a month or two from the last application. But it seems to be a common belief that M4 is one of the better steels (non-stainless) when it comes to not rusting. OTOH, SB (I think) will patina when used for food (prep or eating) even if I just applied Tuf-glide. Same with the white steel on a Carter knife. Anyway, please let us know if the blade's performance has been changed.

Did you read the warnings of the muriatic acid label? I have some of that stuff. I read the label and it says "DO NOT use your Spyderco Stretch knife to open this container if it has a SB laminated blade". :) Just kidding. :D

I do know what you mean about not wanting to pay more attention to the blade steel of non-stainless blade knives. I worked around a swimming pool with my Carter neck knife. I put it in it's sheath and didn't look at it until the next day. I was horrified to see the amount of corrosion. Of course everyone (even me) knows not to put carbon blade steels away without at least a good wiping. AND, now that I am using a Spyderco mule 20 (CTS-B70P blade steel) I'm a little more dissatisfied with the Carter knife. Nothing wrong with the knife. It's a GREAT knife. But it does require more babying than my Mule 20. I even have good swimming with it in it's sheath hanging from my neck. I intentionally didn't wipe it off. I left it in the sheath (kydex) overnight. Absolutely NO corrosion at all. I haven't tried to compare the B70P to the white steel on Mr. Carter's knife regarding edge retention. But I've used the mule a lot and it holds an edge great. So if I have two knives with basically the same edge retention but a lot of difference in corrosion resistance I'd go with the stainless. And it's not just the B70P. There are lots of good stainless steels out there now. And I'm so impressed with the B70P I got three of them. Of the second and third mules I was going to give my son one and I was going to put a really beautiful wood on it as a handle and see how it sells on ebay if I put it up for auction. But I messed up. I asked my wife to use my mule (my keeper) in the kitchen. Long story short. I don't have that knife any more! :) So now I still have 3 but I don't know if I'll sell the third one or give it to my son. I'll get back on track now.

Sorry about your experience with the SB. No matter what your reasons are for disliking it they are your reasons. Did your knife blade have a patina on it before opening the acid? I've always heard a patina helps prevent non-stainless steels from corroding worse. If the acid did effect the steel that it won't hold and edge on that area is it a small enough of an area the tip can be removed and still be inside the handle when close? On mine I have about 1/8" of blade on the spine inside the handle when closed. As I think about it I think a stretch with a shorter blade would be very nice. A full size handle with a shorter blade is great for certain uses.

I think I've rambled enough.

Jack

[3rdGenRigger]

A further point to add...a patina will prevent rust to some degree, but it is a different form of corrosion itself so it will affect the edge and therefore performance. I'd recommend resharpening it and using it again before you judge the performance. My Stretch has some patina (I forced it originally by sticking my knife into an onion for 30 minutes, and I haven't had any problems with corrosion since), and I've used it for lots of varied tasks, work related and not work related. It cut up an Elk steak for me not half an hour ago.

[Ruarch]

Well I've got to change my answer (you know, the one no one noticed and everyone forgot). SB is now on my "junk steel" list. Oh, I know it's great if you prefer wiping and cleaning your blades rather than using them, but for me, it's crap.

And yeah, I know what I'm about to describe isn't "light use," but I don't care.

I've been carrying my SB Stretch a lot lately, for reasons I won't bore you with. I used it to cut the seal off a gallon jug of muriatic acid, and that's when things started to fall apart.

That's all I did... Use the very tip of the blade to cut off the seal. I didn't dip the blade in the acid, let it sit for a few hours, then giggle myself silly. But after the first time, the tip turned to crap. Not rust, really, just sort of like a combination of brass and a turd.

Then, because my knives serve me rather than the reverse, I did it again. Same thing; just the seal. And I did rinse/wipe it off immediately afterward. But this time, the ENTIRE SB portion of the blade turned the copper/turd color. It went all the way through to the back of the blade, so that looking at the spine, you could easily tell where the SB was and where the soft outer layer of the steel whose name I forget is.

But I don't always carry the SB Stretch. I also carry my 2015 forum knife, the S90V Native 5. Yes, I used that one to open a jug of muriatic acid. My knives serve me. And did the S90V cry like a little b**ch? No, it did not. You can't even tell it's been used.

Also used a VG-10 Endura for the same ... this one is between the other two. A bit discolored, but nothing to cry about.

Yeah, I know why this happened to the SB. I know it's not a stainless, and I know you need to pamper it. My point is that it's a crap steel UNLESS you want to spend more time pampering it than using it.

"My knives serve me." G** D*** right. Everyone has different uses and different needs when it comes to knives. What makes Spyderco so great is all the choices they offer. SB is a selective use steel for me as well. While I am of the opinion that it has its place, I don't believe that the cult status it has been given is warranted in my usage.

[jackknifeh]

A further point to add...a patina will prevent rust to some degree, but it is a different form of corrosion itself so it will affect the edge and therefore performance. I'd recommend resharpening it and using it again before you judge the performance. My Stretch has some patina (I forced it originally by sticking my knife into an onion for 30 minutes, and I haven't had any problems with corrosion since), and I've used it for lots of varied tasks, work related and not work related. It cut up an Elk steak for me not half an hour ago.

I agree with this if I understand you correctly. On one or two occasions I've forced a patina on a really sharp knife. Right after that the knife didn't cut as well. It wasn't "dull". It just no longer had that crispy, sharp edge. It seemed like the patina which is a form of corrosion, degraded the edge apex. But just a few strokes creating a small micro-bevel got the knife super sharp again. A small micro-bevel. Small enough you can't see it without looking hard or using a loupe.

One thing that has amazed me is how important it is to have at least a loupe of 30x or so. With that you can see what the edge looks like and you can see what your stones are doing. Once you know what the edge looks like on a microscopic level you can compare that to how it cuts. This will give you an idea of what is happening to the edge when you sharpen.

[3rdGenRigger]

A further point to add...a patina will prevent rust to some degree, but it is a different form of corrosion itself so it will affect the edge and therefore performance. I'd recommend resharpening it and using it again before you judge the performance. My Stretch has some patina (I forced it originally by sticking my knife into an onion for 30 minutes, and I haven't had any problems with corrosion since), and I've used it for lots of varied tasks, work related and not work related. It cut up an Elk steak for me not half an hour ago.

I agree with this if I understand you correctly. On one or two occasions I've forced a patina on a really sharp knife. Right after that the knife didn't cut as well. It wasn't "dull". It just no longer had that crispy, sharp edge. It seemed like the patina which is a form of corrosion, degraded the edge apex. But just a few strokes creating a small micro-bevel got the knife super sharp again. A small micro-bevel. Small enough you can't see it without looking hard or using a loupe.

One thing that has amazed me is how important it is to have at least a loupe of 30x or so. With that you can see what the edge looks like and you can see what your stones are doing. Once you know what the edge looks like on a microscopic level you can compare that to how it cuts. This will give you an idea of what is happening to the edge when you sharpen.

You understand me 100%. I don't use a loupe and go based on feel only at this point, but there's definitely a difference in the edge after forcing a patina...definitely needs a sharpening afterwards, and the stronger the patina, the more the edge is affected. It should cut perfectly after a sharpening.

[Brock O Lee]

SB is now on my "junk steel" list. Oh, I know it's great if you prefer wiping and cleaning your blades rather than using them, but for me, it's crap.

LOL... Let's see, you bought a carbon steel knife, you used it near harsh acid fumes, it did not rust but instead developed a patina. Now it's crap.

I would say your expectations are too high. Right tool for the job man... :D

Mine has been a stellar EDC, with no more babying than any of my other stainless knives. But I would not pick it as a boat knife.