Getting to the mirror edge.... Please help!

C

Cravin01

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Feb 23, 2015
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91
Ok ,

1. I'm a newbie at sharpening.
2. I'm good with tools,I spent a few years as a carpenter and the son of one.
3. I like the precise angles of a guided system so I bought the KME sharpener.
4. The system is diamond stones with 300,600, and 1500 grit.
5. I've added a double sided strop with black and white compound.
6. adding also 30x and 45x magnifying glasses to check work.


I now having a fair amount of experience with it and got shaving edge performance on a Case carbon Trapper but being a fan of super steels I have yet to get there on s30v, s35vn, and plan on trying s110v ,Superblue, and M4.

I'm thinking of adding a 2000 or 3000 grit whetstone, setting up a wheel strop or belt sanding type strop to get the edge razor sharp, I have not achieved a mirror polish with this level of stone and strop on these steels yet, I still see striation marks and close to shave sharp performance but not quite there, I may be doing something wrong also....... All comments welcome!
 
You should be getting shaving edges at 600 grit.
Adding finer stones won't get a dull knife sharper, they just take much longer to get it sharp.
 
Maybe I'm not spending enough time with the stones then? Its sharp but not Sharrrrrp!:grumpy:
 
just my experience, try to stick to just three grit sizes, four at most. master instead your strokes and sharpening angles. i don't see why one needs a progression of more than 5 grits if you're happy with an arm shaver or even a hair splitter. each smaller grit corresponds to more strokes and you're going to spend an entire day needlessly.
 
Let me understand:

1. you can't get it shave sharp with your current KME system? As mentioned above, at 600 grit you can get a "shaving sharp" blade, so I'm assuming that there is a problem with your technique; can you post pics of the Blade? I need to see the apex from above and from the sides

2. you want a mirror polish edge? wet/dry sand paper #2000/ Leather strop with white or green compound/ 3000# up Japanese water stone (Nanaiwa recommended on that specific matter) - all of the mentioned will give you a mirror polish- I recommend not to rush from 600 to 3000/2000 but from 1500
 
It seems like we all go thru that at one time or another, and later wonder why we took so long.
I wandered around for a long time. Good advice...above, from Eytan and the boys.
 
Are you getting a Bur on each side? my brother was having a problem sharpening he wasn't getting a bur and pretty much just scrapeing the shoulder of the edge
 
It might be a problem with s30v or high vanadium steels itself. Regular compound will fail to polish it. You need diamond compound or cbn. Even off an 8k waterstone the edge doesn't feel right because it's not hard enough to really work the vanadium carbides.
 
Sorry it took so long but I couldn't get the camera to focus on the top view of the edge.

20150527_175910_zps2o1dpiv6.jpg


20150527_175733_zps5pokleo2.jpg

A closer look. The best I could do with a magnifying glass a smartphone camera:o

20150527_175222_zpsm4obbp94.jpg


20150527_174832_zpsrogkxpak.jpg
 
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^^That'll need a fully-executed diamond sequence to finish off, IF mirror polish is the goal. The last pic still seems to show a much coarser edge finish than implied by the '1500' diamond stone you indicated in your OP. What brand/make are your diamond hones? Ordinarily, even a 600 (Fine, 25µ) DMT would leave a finer scratch pattern than what's pictured, and the DMT EF (1200/9µ) takes it well beyond that, to a VERY FINE satin finish; an EEF DMT (8000/3µ) should take S30V to very near-mirror, and a stropping sequence with diamond compounds (on wood) in 3µ and finer will bring up a mirror very quickly, IF all prior steps are done to full capacity. Either your diamond hones are much coarser than what their grit rating implies, or the scratch patterns from the coarsest hones weren't thoroughly removed in subsequent grit stages (this would be the most common hurdle to get past, the vast majority of the time).

Beyond doing what's needed with the hones themselves, the black and white compounds won't help much in bringing out a mirror, after a certain point. Below about ~5µ or so, the vanadium carbides must be polished in addition to the matrix steel, and diamond or CBN compounds are the only ones capable. If staying with the black & white, S30V won't go beyond a hazy mirror (the un-polished vanadium carbides are the 'haze'), or essentially whatever's left by the finest diamond hone.

(Also as mentioned by others, shaving sharpness should come by ~600-grit or so; if that's still not happening by 600/1500, it's another indicator that each grit stage wasn't fully executed to full apex & refinement).


David
 
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I don't know who provides the diamond hones,Its just labeled KME Gold Series Diamond Hones. I'll spend more time with the 600 and 1500 grit and get the wood strop with some diamond compound and see how I fair. Thank you for all your help David!

Paul.
 
Use the sharpie trick where your sharpie the bevel and your goal is to remove it when sharpening. It works quite well on guided setups especially since if there is any left it makes it easier to tell you definitely didn't fully apex the blade. Get the knife sharp on the coarsest stone you're using, your subsequent stones you can think of as changing the finish on the blade. Leaving the knife at a more coarse stone will give you a more toothy blade which works better in slicing applications and moving up in the grits will give you a more polished blade which works better for push cutting. They are both sharp, but sharp in different ways.

Try to limit the amount of stones your using right now and focus on technique, then start adding more stones. Beyond that you already got a lot of good advice from other people here. Just remember no matter what your using your goal should be the same a fully apexed burr free edge.
 
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