New EPA user / sharpener | Some stone questions + a few general sharpening questions

C

cFine

Joined
Dec 2, 2011
Messages
66
Hey everyone, first let me quickly do a little intro that may help answer a few of my questions.

Just recently got into knives rather seriously and right off the bat I want to be able to sharpen all my knives to a very high degree of sharpness. To be honest, time is not really an issue at all in terms of sharpening. I have been reading a LOT of amazingly useful posts here the last few weeks and I think I have gotten to the point where I have read enough to get me started with sharpening my knives via the EPA system.

Here is basically what I want to get out of this system and what I will use it for presently, and in the future.

I want to start off sharpening some crappy knives (Friend has like 200 junky knives, so I will have as many as I need to practice on), then progress to sharpening my own knives to a mirror polish and bevel changing, as precise as I possibly can with this system. After I get them to where I want (changing bevel angle + mirror polish), I will just be touching them up every other week or so. What stone progression should I use to really get the most out of this system for the "first" sharpen, and then what should I use to basically upkeep them? The first of my knives, which I carry every day and the one I will focus on first is an S30V Sage 1. So here is what I was thinking. Start with Atoma 140 for setting the bevel, then go 400, 800, 1000, 3000, 5000, 10000 all Chosera. Then HA strop for EP first using Chromium Oxide .5 micron, then finishing with HA Diamond Spray .25 micron. Am I missing anything? What changes should I make?

The next application will be further down the line, and will involve sharpening many more knives to generally the same sharpness. For this I just want to make the knives have an edge that can slice paper with ease but can hold up with general usage (as much as I can with just sharpening, not factoring in the steel), basically wondering the stone progression and bevel angle to get an edge for that use that I can do on most generic steels. Was thinking getting 40 degree via Atoma 140, then going 400, 600, 800 grit Chosera, then just ending with HA strop on EP + Chromium Oxide .5 micron. I still want to be able to make it look very polished, but want to keep it at 30 or 40 degrees (or whatever angle would be better for these applications).


In terms of the EPA system itself, I do have a few questions about that, which I hope can be answered, if not I can always call them or CKtG.

In terms of little trinkets that I think I need, I think the drill stop collar, angle cube, DMT XXC to flatten stones (Can I / should I flatten them all with this, or should I get a different DMT plate for certain Chosera's), and I kinda want that microscope that CKtG has on their site for $65, to examine edges.
What would you suggest to remove burrs?

On that note, does someone know somewhere that explains burrs for a beginner? I think I know what it is, so correct me if I am wrong.
When you sharpen one side of a knife, the edge basically rolls over a little at the top, so the trick is to find it when its the smallest, and that's when you know to switch to the other side of the blade then sharpen that side and feel for the burr on the other side, rinse repeat?
So my questions basically are: When do you know when to stop sharpening each side, and when do you know when to stop sharpening with a certain stone and move on to the next?

Last two questions for now:

I don't understand how you are able to keep the blade perfectly still when holding it on the "ramp" while you sharpen it, from all the videos I have watched, it seems to slide a little up and down when you are working the arm on the Apex because the spine is curved (usually) so it does not sit flush with the piece that is meant to keep it from sliding down.

When you are adjusting the piece on the ramp that keeps the blade from sliding down, how do you know how far to adjust it (I know you want the blade to overhang, but by how much? Because if its too much or too little, wont the angle change?



Really appreciate any help that anyone can provide as I am a novice so I want to absorb any and all advice and positive criticism that you guys have to offer.
 
from reading your post it seems you do know what a burr is. when you see the burr form on the entire length of the edge you switch sides and get the burr to form on that side. i never go over 400 grit on any knife i sharpen so if 400 was my last grit i would move to a strop to finish the edge after getting the burr to form on the other side. (i myself use a slotted paper wheel instead of a strop)
 
So say a 400 grit Chosera + stropping (what would be a good paste that would make it pretty polished, but will still help a generic steel cut a wide range of materials? I was thinking the Boron Carbide 1 micron paste?) should yield a semi polished edge that would be sharper than the factory edge for most knives? That would be perfect.
 
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Keep in mind that the grit ratings for waterstones are not the same as for a sanding belt. You're looking for a waterstone in the 800-100 grit range to equal (approximately) a 400 grit belt on a power sander. It'll give you a tough edge that has a good balance of characteristics.
 
i use a medium grit compound on the slotted wheel. it polishes the edge yet leaves it toothy. i have sharpened knives with an 80 grit belt and finished them off with the medium grit compound and had the owner treetop hairs with it.


check out some of the vids at my website of knives i have sharpened. here is one to check out. i'm cutting free hanging newspaper in this vid. http://knifetests.com/kII.html
 
Oh, ok so Richard, you are talking about a belt, gotcha. So what would be the appropriate stone to start with if I am ending at lets say a 1000 grit waterstone? Something like 400, 800, 1000? If I do end at 1000, would stropping with just the leather be ok to give it a slight polish? Or would I be better off using a compound that will add some toothiness but not leave the bevel too polished, like the silicone carbide, since its 2 microns.

Oh also when you polish lets say a generic knife steel with a 20-25 degree per side bevel that has been sharpened with a 1k stone and you are ending with something like 1 micron paste or .5 micron paste, is that going to severely hinder the edge life? Because the 1k stone is the one doing the major sharpening while the polishes are just making it more shiny (up to a point). So would it be better to end with a 800 grit stone, so that there is a little more material on the bevel so that the polish doesnt make the edge too weak?
 
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cFine said:
Oh, ok so Richard, you are talking about a belt, gotcha. So what would be the appropriate stone to start with if I am ending at lets say a 1000 grit waterstone? Something like 400, 800, 1000? If I do end at 1000, would stropping with just the leather be ok to give it a slight polish? Or would I be better off using a compound that will add some toothiness but not leave the bevel too polished, like the silicone carbide, since its 2 microns.
Click to expand...

You can't compare sandpaper grit to waterstone grit because they are not the same. A 1k waterstone is more like 400-600 grit sandpaper in American standard.

Check my Sig line for info about the burr and intro sharpening.

For cheap knives I'd stop at 1k and not even worry about stropping. A burr is controlled by how much force you use in sharpening so if you do your part you can have a 1k edge that's burr free and Sharp without a strop.
 
I wouldn't go any lower than a 220 grit waterstone for reprofiling. Any more aggressive and you'll never get the deeper scratches out.

I strop with 6 micron diamond or the black emery from Sears when finishing my coarse edges. A lot of what works best will depend on the material you're using for a strop - the more conformable it is the larger the particle you can strop with and get the same effect as a smaller particle on a harder surface. I've had good luck using 220 grit silicon carbide grit on the rough side of some leather.

Generally speaking - The finer stropping abrasives will smooth out the grind troughs more - making the edge catch less when used for drawcutting, but improve performance for pushcutting. It also slightly convexes the apex after repeated or prolonged stropping, gradually making the angle of the cutting edge larger, degrading performance - at which point it needs to be put back on a stone.
 
I know a little about waterstones, general stuff. Knifenut is the guy to talk to about specifics - not sure but I believe he has direct experience with the Choseras as well.
 
I am actually thinking it would be better to just finish with 800, then only a few passes on the strop (smooth side of the HA genuine honing leather) without compound, so I dont completely loose the toothiness, but still refine it a little. 800 looks pretty polished now that I see it and has plenty of toothiness.
 
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Yeah, just going to start some tests, I mean I do have 50 or possibly close to 200 generic cheaper knives to just experiment with.

Something else I just thought about, can you still put a mirror polish on an edge WITHOUT making it extremely sharp? So that you can have the LOOK of the mirror polish but can still retain the edge retention of the thicker edge you would get from stopping at 800 (assuming you don't just keep going and going and going with the 800 ).

Appreciate all the help given, I really do. I just want to do this the RIGHT way and be prepared as possible. I do understand that nothing can be substituted for practice. Will be getting plenty of that in the upcoming months.
 
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I can't see why you couldnt put a mirror polish and screaming edge, then move the guide a little wider, and put a toothy edge on with a lower grit on the micro bevel.
 
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