Two Questions on Grinding

[Trout Hound]

Hello All,

Okay, two questions:

First of all, to what extent is it okay to grind a specific portion of a blade without working the entire length? There is sometimes that one stubborn section that apexes last, and I don't want to overgrind the rest of the blade. By the same token, I've noticed that too much grinding on one section can develop a clear transition along the bevel line, which then has to be worked out. I feel like this probably comes with experience, and I think I'm starting to get a feel for it, but I thought I'd ask.

Along the same line, how do you deal with a new blade that has a slight recurve at the heel from the factory without jacking up the bevel further up the blade?

Thanks!

 

[HeavyHanded]

In my opinion, if one stretch needs grinding more than another I grind right there. Occasionally I'll have to smooth it into the rest of the edge but there is zero sense in grinding down the rest of the edge if it doesn't need it.

The only time it can be a real issue if if you do a ton of work to the straight portion leading into the belly will sometimes make a broad bevel transition into a smaller one - this is easily fixed by just smoothing it into the rest of the bevel.

The factory recurve I tend to grind right at that spot for a few before tackling the rest of the edge - small movements with off hand fingertip right on top of it. If I have to "fix" it I'll just keep grinding it back till it lines up with the rest - having a nice clear sharp corner on a hard stone makes this a lot easier. Normally I grind it back a little every time I hit the knife - if it never gets worked out all the way is not really an issue for performance, but I won't ignore it or that recurve will only get larger.

 

[bgentry]

"Selective Grinding" is one of the 7 secrets of sharpening. You'll have to play with it some to see how much you can grind in a certain area before it starts to affect the look or feel of the bevel. Generally speaking, when I'm grinding by hand, I'll do up to 12 or 15 strokes, concentrating in one area, before then doing 2 or 3 "blending strokes" to make sure the bevel stays even.

You may find you can do more than that even. Use your eyes to observe the bevel (another of the 7 secrets) during grinding. If you see the bevel beginning to develop a wide spot or something else, adjust and move forward.

I also do this with powered sharpening, and I'd like to think that I get faster results *and* grind off less metal as a result. It's very normal for some parts of the blade to be much more dull than others. With most user blades (including kitchen knives), the first 1/3 of the blade near the point is usually the dullest, because it gets used the most. Especially blades with belly near the tip. The belly is always more dull than the straight section. I also find that I almost universally have to spend extra time on the point if I want the blade to have a sharp point when I'm done. People tend to use and abuse the points of blades a lot.

Good luck!

Brian.