Freehand Sharpening Problem

[Bugout Bill]

Alrighty, I am relatively new to freehand sharpening, but I have gotten the basics more or less down to pat. I can get very sharp edges, but I am having alot of trouble sharpening the tip/belly area of blades. I had a lot of trouble with this when I only used the sharpmaker too. What do I have to do to sharpen that area that is so different from sharpening the main edge of the blade?

Thanks for any imput.

 

[bgentry]

You are probably only touching the shoulder of the blade in the belly and tip area. In the rest of the blade, you seem to be getting to the edge since you can get it sharp there. I'm assuming you are raising a burr in the straight portion, but you can't get a burr in the belly?

If so, it's just a geometry problem. It's two things together:

1. All knives with belly require the sharpener to raise the handle of the blade as you move through the belly area. This is because the edge is curving back away and thus getting thicker, requiring an increased edge angle. Yes, that's right, the edge angle in the belly is different than the angle in the straight section.
2. Many modern "tactical" knives have super thick crazy geometries, especially near the point. I've found that I've needed to considerably thin the bevel in the belly of a number of modern folding knives. It seems silly to me that they make them this thick, but it's reality. Conversely, sharpening something like a kitchen knife that has belly to it is quite easy and doesn't require any thinning. It just requires #1 above: Raise the handle and follow the curve.

Technique here is a little hard to describe, but it's intuitive once you've seen it. Here's a video by BF member knifenut1013 that shows how he sharpens. The whole series (5 parts) is great to watch, but it's a little long. In this first one, pay attention at the 5 minute mark (or so) where he talks about following the curve and applying pressure. Then again around the 14 minute mark. Sage advice here.

[video=youtube;2VizLyNOr0s]http://www.youtube.com/watch?v=2VizLyNOr0s[/video]

Finally, use sharpie on the edge and see if you're hitting the edge in the belly or if you're just hitting the shoulder. Reapply often and check your progress.

Brian.

 

[Bugout Bill]

You are probably only touching the shoulder of the blade in the belly and tip area. In the rest of the blade, you seem to be getting to the edge since you can get it sharp there. I'm assuming you are raising a burr in the straight portion, but you can't get a burr in the belly?

If so, it's just a geometry problem. It's two things together:

1. All knives with belly require the sharpener to raise the handle of the blade as you move through the belly area. This is because the edge is curving back away and thus getting thicker, requiring an increased edge angle. Yes, that's right, the edge angle in the belly is different than the angle in the straight section.
2. Many modern "tactical" knives have super thick crazy geometries, especially near the point. I've found that I've needed to considerably thin the bevel in the belly of a number of modern folding knives. It seems silly to me that they make them this thick, but it's reality. Conversely, sharpening something like a kitchen knife that has belly to it is quite easy and doesn't require any thinning. It just requires #1 above: Raise the handle and follow the curve.

Technique here is a little hard to describe, but it's intuitive once you've seen it. Here's a video by BF member knifenut1013 that shows how he sharpens. The whole series (5 parts) is great to watch, but it's a little long. In this first one, pay attention at the 5 minute mark (or so) where he talks about following the curve and applying pressure. Then again around the 14 minute mark. Sage advice here.

[video=youtube;2VizLyNOr0s]http://www.youtube.com/watch?v=2VizLyNOr0s[/video]

Finally, use sharpie on the edge and see if you're hitting the edge in the belly or if you're just hitting the shoulder. Reapply often and check your progress.

Brian.

Thanks a bunch. I can get the edge sharp up to the belly area, after than I am ok. I'll try angling the blade as I get to the belly. Sharpie on the edge wouldn't be a half bad idea either.

The video was very helpful BTW.

 

[adubbz]

Sharpie on the blade has saved my sanity many times so far. I'm fairly new to sharpening and mostly use a sharpmaker. I found that almost ALL of my blades had a bevel that was too obtuse and I was not hitting the edge. I took a course stone and rebeveled them all and now they sharpen up with the sharpmaker no problem.

As to what you were asking about - I think first put the sharpie on and make sure it's HITTING the edge of the blade. Second, on my sharpmaker, to hit the belly on some knives I slide my hand straight back along the main portion of the blade, then when I get to the curve/belly, I bring my hand a few inches IN(left when on the right stone, right when on the left stone.) That way it hits it better.