Sharpening My ZT0350SW In S30V

[Ares1307]

Ive had this knife for a few weeks and have been using it lightly, mostly cutting cardboard boxes, paper, and thin plastic ties. I have sharpened it about 6 or 7 times with my Spyderco Sharpmaker + Ultra Fine Stones to finish with. I have noticed the blade gets very shiny but there are still the original "cuts" in the blade from the factory. I dont really know how to discribe the cuts, but you know when you get a new knife and the edge has big teeth and you sharpen it and the teeth get smaller and smaller until it is polished? Well it almost looks polished because of the shine, but the teeth from the factory are deep in the edge. I dont have a good enough camera to get a good picture so I hope my discription is enough. I want to know why these factory cuts havent gone away yet, and how to get them out without messing up my knife. I have a Spyderco Zulu with the same S30V steel and that knife is much easier to sharpen and polish, but it chips easily I would guess that is due to it being thinner and heat treated differently. Thank you for all of your help.

ARES

[Obsessed with Edges]

It'll take a VERY long time to remove the original grind pattern from S30V, with the Sharpmaker. This steel is known for it's 'abrasion resistance' (due to abundant amounts of vanadium carbides in it), which translates essentially to 'doesn't sand/grind/polish easily'. The Sharpmaker is great for touching up (micro bevelling), but the ceramic rods won't be aggressive enough to quickly remove the large amount of metal needed for polishing the bevels. Diamond hones will work much better for this, in a C/F/EF/EEF sequence, then followed by the ceramic rods (at least F/UF). The more 'mirror' you expect to see in the result, the more important it'll be to use a tight sequence like this, followed by stropping with diamond paste such as 6/3/1 micron.

[Ares1307]

Thank you very much, Ive been looking for a good all diamond system that can handle recurves. Any suggestions on which could handle various recurved blades?

[Obsessed with Edges]

Thank you very much, Ive been looking for a good all diamond system that can handle recurves. Any suggestions on which could handle various recurved blades?

If this were just a matter of simply re-bevelling or touching up, any diamond system with relatively narrow hones could handle it. I used a Lansky system (including one diamond hone) to re-bevel & somewhat polish a ZT-0350. The Lansky's hones are narrow (about 1/2" wide), which fits the ZT's recurve well enough. The thing that makes it somewhat tougher for your situation, is trying to thoroughly polish the recurve. That'll have to be done very delicately with flat hones, because only the corners will be making contact, and it'll take a long while in that manner.

You might have some success using silicon carbide sandpaper (wet/dry type) on a radiused backing, like a pipe or other cylinder. But, with S30V, that could be slower than with diamond. I still think it'd be worth trying, however, as the curved backing for the sandpaper will make it much easier to get good, wide contact with the blade's recurve. There are a few radiused diamond sharpeners on the market (diamond rod-type sharpers), but most are only available in finer grits (fine/ef).

Probably the 'best' way to polish a recurved blade in S30V would be to use a belt grinder. But that obviously has some risks and a fairly steep learning curve too, if you haven't used one.

[Ares1307]

Thank you for the feedback. I may go with the lansky diamond deluxe system and try to use a strop to polish with. The worksharp knife and tool sharpener I mentioned is a small belt sander with a sharpening guide.

About the polishing part.. do you guys think I would have to take any extra messures to strop a recurve? Would I have to use leather or could I use balsa? Im just thinking that for at least the speed bump I would probably need to use a leather strop because of its difficult recurve. Ive never stropped before so any advice would help.

[Obsessed with Edges]

Thank you for the feedback. I may go with the lansky diamond deluxe system and try to use a strop to polish with. The worksharp knife and tool sharpener I mentioned is a small belt sander with a sharpening guide.

If you do decide on the Lansky, they have some ceramic finishing hones (600, 1000 and the 'Super Sapphire') that can also help with polishing (used AFTER the fine diamond hone), if you want to take it that far. Those hones aren't part of the diamond kit, but can be purchased separately.

I actually wasn't aware that you had the Worksharp. I haven't used one, but a lot of others here have. Reviews seem to be pretty good. I don't know what it's capable of, in terms of polishing blades (especially S30V, which doesn't polish easily anyway), but if you have one, I can't see any downside to trying it out (practice on 'cheaper' knives first ).

About the polishing part.. do you guys think I would have to take any extra messures to strop a recurve? Would I have to use leather or could I use balsa? Im just thinking that for at least the speed bump I would probably need to use a leather strop because of its difficult recurve. Ive never stropped before so any advice would help.

LOTS of options for stropping. I always encourage others to try as many variations as possible, because there are so many variables determining what works 'best' for a particular steel. For starters though, diamond paste (6/3/1 micron) on balsa or leather is always versatile. For S30V, I'd personally choose diamond on balsa first. And for the recurve, balsa will be easy to sand/shape to fit the blade, if you wish to do so. Some narrower flat strips of balsa would be sufficient, though (size-wise, think along the lines of the Lansky hones' width). If you do use leather, I believe firmer is always better.

[Ares1307]

I dont have the Worksharp, Im considering buying that or the lansky.. sorry I have another post about sharpeners so I thought I mentioned it in this post. Im not too worried about polishing, as long as I can repair and reprofile the knives and get them to a good edge then I can finish up on my Sharpmaker + Ultra Fine rods if I have to. Do you know what the micron is on the Super Sapphire stone?

[Obsessed with Edges]

I dont have the Worksharp, Im considering buying that or the lansky.. sorry I have another post about sharpeners so I thought I mentioned it in this post. Im not too worried about polishing, as long as I can repair and reprofile the knives and get them to a good edge then I can finish up on my Sharpmaker + Ultra Fine rods if I have to. Do you know what the micron is on the Super Sapphire stone?

For repair & re-bevelling, I think you'll be OK with the Lansky. It'll still take time, especially on S30V, so patience is key.

I don't know what the equivalent grit would be for the Super Sapphire. When trying to compare ceramics to diamond or silicon carbide, or any other abrasives, the published 'grit' numbers usually don't mean much anyway. Different standards for each. Generally speaking, ceramics are a lot less aggressive for a given 'grit' number. I have used the Lansky 600 & 1000 ceramics a lot, and the combination (in a suitable tight sequence) will produce a pretty nice mirror on most steels (S30V will always be more challenging). The Super Sapphire is supposed to go beyond what those two can do, and comments from people here who've used it are pretty positive.

[OHALLUM]

While the worksharp is a great tool, you can get better results freehanding with it instead of using the guides. Be aware that you will wind up with a beveled edge using it, as it is a slack belt system without a backing on it. I have one and love it for quick sharpening of my kitchen knives, and using it freehand to sharpen garden tools, and lawnmower blades. I have used it to repair bad tips on knives, and to make some straight edge knives out of some serrated kitchen knives. Great little tool, but not so great for your flat ground or v bevel knives.

[Ares1307]

Thank you guys again for all the help. I think I will go with the Lansky Diamond plus all the ceramic fine stone probably. Thank you for the heads up on the WS I didnt even think about it reshaping my edges. Well I hope the Lansky can handle my recurves, mainly my Kershaw Speed Bump. They arnt that bad to sharpen on the Sharpmaker, but its not aggressive enough to do anything but light touch ups. I have yet to remove the factory cuts in the edges to both my Speed Bump and ZT0350SW. The sharpen up good and sharp, but the original cuts in the edge are holding the blade back from getting a good polish. And I just noticed my Speed Bump has two different angles, one side is a 20 the other is closer to a 15, and the Sharpmaker cant handle a reprofiling job. Im just going to wait until I get my new Lansky and then fix it. Whats really odd is that the angle difference is only after the recurve, its only the straight part of the blade that is off. I could just send it to Kershaw to get it fixed, but I just got it back yesterday from having it sent out for a custom clip so Im not ready to part with it again. Thanks again for all your help! Cant wait to get my Lansky.

[Ares1307]

Alright guys, just an update.. I went ahead and order the Lansky Diamond Deluxe system + the universal metal mount and the Super Sapphire stone. Thank you all for your help and advice. Wish me luck.