Lopsided blade angles.

[Giunta]

Hi folks,
I've been sharpening all my knives using the Lansky system. I haven't read much about sharpening so I'm probably doing something wrong but I'm getting the result I want. My aim is to sharpen knives to the point where they shave hair. Some knives took more work but I've got them all to the point of shaving. One thing that I'm not sure of though is the original grind from the maker. I checked on the net and two blades were hollow ground and one was flat. The flat was very quick to sharpen but the hollow weren't. I grabbed the most course stone I had and went to work on the hollow grinds. The S30V took ages longer than the 440C which is what I expected.

I went to work on the hollow grinds until there was a burr on the other side. I then flip it over and grind until there is a burr on the other side. Problem is, when I flip it over I spend like 10 seconds getting that burr where as the other side took FOREVER. I then move down through each sharpening hone, doing both sides until there is a burr. I do get it razor sharp but I'm thinking the angle on the side I worked on least is all off whack compared to the other side. I can only assume my knives all have a modified chisel grind on them.
eg. If I sharpen at 20 degrees each side then the side I worked on most is a flat 20 degrees but the other side is either a modified hollow grind or flat grind that came from the maker(depending on which knife I sharpened).

At the moment I'm happy but I'd prefer a flat grind that is the same angle on each side. But to do that, how do I tell the side I worked on least is the correct angle?

Any help is appreciated.

 

[Cliff Stamp]

I went to work on the hollow grinds until there was a burr on the other side. I then flip it over and grind until there is a burr on the other side. Problem is, when I flip it over I spend like 10 seconds getting that burr where as the other side took FOREVER.

In general it is frequent that knives are uneven, I have seen a lot of edges where one side was 10 and the other 30 or one was 15 and the other 25. If you start on the obtuse side and then flip over you will notice exactly what you saw, one side has to be regound and the other just gets microbeveled. The edges will even out over time, just alternate which one you start with. You don't need to actually keep track of it, just do it randomally. For example each time you start sharpening look at your watch, if it is between 0 to thirty minutes after the hour then start on the right side or otherwise start on the left.

But to do that, how do I tell the side I worked on least is the correct angle?

If you are using a Lansky the angles should be preset. If you are grinding freehand you can just estimate the angle from the height of the spine from off the stone. The angle will be very close to :

(height of spine off stone)/(blade width)*60

-Cliff