My sharpening journey. Edge Pro Apex.

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flylikeIdo

Joined
Mar 22, 2013
Messages
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I have lurked on here for a while and figured I would make a post. I have started to feel like my sharpening is a bit of OCD but precision makes perfection right?

One day while cleaning salmon I wondered why I was never able to get my knife as sharp as the day I bought it. I started looking at sharpening systems. I had the electric three grit Chef's Choice and the final stage was decent but it never had that edge I wanted. I had an old oil stone which belonged to my grandfather. Freehand was not for me though. I purchased the Lansky system but hated the rods and how the angle would vary from the attachment point. Also when the stones were not exactly the same thickness I could never progress to the next stone with the same exact angle.

I did a bit of research and purchased the Edge Pro Apex. Someone recommended the drill stop collar (which is an absolute must have btw) and I was off sharpening everything I could find. I literally thought "I wonder how sharp I could get one of those butter knives."

The one thing I have noticed with the edge pro is that the stones can wear unevenly from one end to the other, even with regular flattening sessions. I work for a paper company and have access to a digital IDS thickness gauge. .0005" +/- .001" Accuracy. I flattened all of my stones using the pencil mark trick. I started measuring my stones and noticed that one end would be a bit thicker than the other end. For example one stone was 5.91 mm and the other side was 6.01 mm.

I took them back to the flattening stone and applied more pressure on the thicker end until the match perfectly. End to end, side to side same exact thickness.

The before and after difference was drastic. My knives went from being very sharp to ridiculously sharp. Now when I clean salmon I know my knives are much sharper than a brand new knife and the fillet quality proves it.

A lot of the information I have learned in the past 18 months since I started obsessing about metal edges has come from this site and the informative posts.

Thanks,

John
 
flylikeIdo said:
I had the electric three grit Chef's Choice and the final stage was decent but it never had that edge I wanted.
Click to expand...

I am ashamed to say that I also own one of these, but it's all part of a learning process, I guess.

flylikeIdo said:
Someone recommended the drill stop collar (which is an absolute must have btw)
Click to expand...

100% necessary. I really don't know why one isn't included in every EP kit.

flylikeIdo said:
I flattened all of my stones using the pencil mark trick. I started measuring my stones and noticed that one end would be a bit thicker than the other end. For example one stone was 5.91 mm and the other side was 6.01 mm.
Click to expand...

I can understand your desire for such precision, but I think that variability in how you draw the knife across the sharpening stage and how you move with each pass of the stone will introduce more change in the precise sharpening angle than a 0.1mm difference in stone thickness from end to end.

Actually, I think I am going to do the math on this...


EDIT:
Keep in mind that your sharpening angle is only going to be precisely consistent from the beginning to the end of each stroke if your knife blade is perfectly straight and you are sharpening at an angle where the arc of the swinging stone arm is perpendicular to the upright bar on which it pivots (i.e. 20 degrees). Any lesser or greater angle, and there will be a tiny bit of angle variation across the swing of each sharpening stroke.

As for the 0.1mm difference between the two ends of a worn and then flattened stone, a variation in the positioning of the blade edge of 0.3mm with relation to the edge of the sharpening stage (over or behind the exact edge of the sharpening stage) will produce the same variation in sharpening angle with each pass of the stone. In other words, you would have to be placing the blade within less than +/- 0.3mm of the edge of the sharpening stage with each pass AND sharpening at a 20-degree angle for this variation in stone thickness to make any difference. This 0.1mm variation in stone thickness makes even less difference as you move away from a 20-degree sharpening angle, though this will depend on the length of the arc you make with the stone arm with each stroke.

I don't think you need to be concerned about a 0.1mm difference (or more) between ends of your stone.
 
Last edited:
John,

That's a good tip! Thank you.

I've noticed that the results from my EP aren't quite as good as when new. I bet it's the same problem.

My knives are still sharper than anything I've achieved before the EP, but just not quite as spectacular.

Hopefully my calipers are up the the job on this.
Allen
 
sharpandsafe said:
I am ashamed to say that I also own one of these, but it's all part of a learning process, I guess.



100% necessary. I really don't know why one isn't included in every EP kit.



I can understand your desire for such precision, but I think that variability in how you draw the knife across the sharpening stage and how you move with each pass of the stone will introduce more change in the precise sharpening angle than a 0.1mm difference in stone thickness from end to end.

Actually, I think I am going to do the math on this...


EDIT:
Keep in mind that your sharpening angle is only going to be precisely consistent from the beginning to the end of each stroke if your knife blade is perfectly straight and you are sharpening at an angle where the arc of the swinging stone arm is perpendicular to the upright bar on which it pivots (i.e. 20 degrees). Any lesser or greater angle, and there will be a tiny bit of angle variation across the swing of each sharpening stroke.

As for the 0.1mm difference between the two ends of a worn and then flattened stone, a variation in the positioning of the blade edge of 0.3mm with relation to the edge of the sharpening stage (over or behind the exact edge of the sharpening stage) will produce the same variation in sharpening angle with each pass of the stone. In other words, you would have to be placing the blade within less than +/- 0.3mm of the edge of the sharpening stage with each pass AND sharpening at a 20-degree angle for this variation in stone thickness to make any difference. This 0.1mm variation in stone thickness makes even less difference as you move away from a 20-degree sharpening angle, though this will depend on the length of the arc you make with the stone arm with each stroke.

I don't think you need to be concerned about a 0.1mm difference (or more) between ends of your stone.
Click to expand...

Partypooper.

:D
 
The drill stop collar is a massive time saver. As is the angle cube for fast dead on angles. Chosera stones are also very nice to have. They polish MUCH better than the tapes. And if your going to be OCD about it, stropping on the Edge Pro is money. Just when you think you can't get a piece of metal any sharper you go down to .25-.1 micron and see what scary sharp really is.
 
That sucks you cant get a good edge with the ep, you should stick to what works best for you. Some people are better off paying a pro I guess!
 
sharpandsafe said:
Keep in mind that your sharpening angle is only going to be precisely consistent from the beginning to the end of each stroke if your knife blade is perfectly straight and you are sharpening at an angle where the arc of the swinging stone arm is perpendicular to the upright bar on which it pivots (i.e. 20 degrees). Any lesser or greater angle, and there will be a tiny bit of angle variation across the swing of each sharpening stroke.

As for the 0.1mm difference between the two ends of a worn and then flattened stone, a variation in the positioning of the blade edge of 0.3mm with relation to the edge of the sharpening stage (over or behind the exact edge of the sharpening stage) will produce the same variation in sharpening angle with each pass of the stone. In other words, you would have to be placing the blade within less than +/- 0.3mm of the edge of the sharpening stage with each pass AND sharpening at a 20-degree angle for this variation in stone thickness to make any difference. This 0.1mm variation in stone thickness makes even less difference as you move away from a 20-degree sharpening angle, though this will depend on the length of the arc you make with the stone arm with each stroke.

I don't think you need to be concerned about a 0.1mm difference (or more) between ends of your stone.
Click to expand...

+/- 0.3mm from the sharpening stage may produce the same inconsistency as the 0.1mm variance in the stone, but that doesn't mean that the 0.1mm variance doesn't make any inconsistency at that point. It becomes compound interest, if you're not exactly at the sharpening stage, and you have 0.1mm across the stone, then your edge inconsistency will be amplified. The most convincing thing to me, however, is that the OP noticed a drastic difference when doing this. I don't have all the variables on the Edge Pro Apex to do the math, but if you'd like to share some of them or your calculations I'd love to nerd it up some more :)
 
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