Press on or change up my approach

J

JorgeSparrow

Joined
Jan 9, 2019
Messages
4
Hey guy and gals,

So I've been working to salvage a Gerber that was given to me because it was extremely dull. It looked like someone had been cutting from the belly to the tip on concrete.

This was the first time using an edge pro apex I inherited. Took more than a minute to get the stones resurfaced but I've been happy with how quickly the coarse stone cuts. That's the only stone I've used on this knife so far.

As you can see from the pictures linked at the bottom below I'm beginning to get some bevel creep towards the tip but I have a little over 1/16" at the tip that is still crap. I get a good burr from just behind the crappy part of the tip back to 3/8" ish from the change to serrations.

The other side of the blade, w/out the logo, is a little wonky too. Close to the serrations, the bevel is narrower than the logo side but the bevel creep towards the tip is wider than the logo side. I did some strokes that were focused on the tip rather than the entire edge and that seemed to speed up the improvement of the tip. I kept the count per side even. The blade is short and centered over the middle of the EdgePro table so the amount of bevel creep was surprising to me.

Let's ignore the serrations for now. With the pandemic, we should all stay focused on the REALLY important things in life... like non-serrated knife blades.

I'm open to any and all suggestions from EdgePro-pro's but, generally speaking, should I:

A- Just keep going, bevel creep be damned, focusing more strokes on the tip.
B- Work the entire edge until the tip finally gets an apex again.
C- Get out a junker knife until I figure out what I'm doing on the EdgePro. I have the free time after all...
D- Try some totally different approach.
E- Wait until they start selling Corona beer again then buy another knife cause I've ruined this one.

I'm a reasonably functional sharpener/maintainer of our kitchen knives and filet knives using crock sticks so maybe I was overconfident using the EdgePro?? I have used an old lansky system (guided fixed angle) for hunting and EDC knives in the past.

Using the crock sticks all our kitchen knives just seem to keep getting sharper and sharper nowadays... I have a decent understanding of some of the basics: grit, pressure, burrs, micro bevels and, although it's taken me a while to get there, I'm now extremely proficient at watching incredibly boring youtube videos about knife sharpening.

Feel free to:
- just vote on one of the multiple-choice options above,
- offer your expert opinion
- offer your novice opinion
- or write a self-absorbed soliloquy similar to mine.

Seriously, I wrote this out of the kindness of my heart because I KNOW how bored you are and your family is concerned your knives, like my kitchen knives, might be getting a little TOO sharp for the comfort of the people you've been quarantined with.

Thanks in advance!
George

Tip: https://photos.app.goo.gl/oigitxHsvpVa6wth8
Logo side: https://photos.app.goo.gl/iSY7ttVdTnQxw8L7A
Non-logo side: https://photos.app.goo.gl/e2b4B21aYtwKVG1S6
On the EdgePro: https://photos.app.goo.gl/RNpbJJhCFW8Jc1K18
 
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A. keep going - maybe focus strokes on logo side to match the bevel and get the tip sharpened.

Alternatively, if you do not have use for tip, you can leave it alone for time being but it will have to be tackled at some point.
If you don't like the bevels so wide you can thin the knife but it will not look any prettier especially since its coated.

P.S.There are advanced techniques like canting the knife upward to maintain the bevel width at tip but I am sure you don't want to go into that.

EDIT: How the knife was ground can also affect bevel width at particular points so you may want to analyze that.
 
Short answer: While your results look "strange" to you, they are consistent with what you should get, with a constant edge angle, on a knife like that.

Long answer: Wide tips on knives are something that people think look bad and they wonder why they happen. The answer is blade geometry. On the majority of blade shapes, the tip of the knife curves up towards the spine. On most of those knives, the blade stock near the spine is far thicker than the blade stock further from the spine.

But with a constant angle, as you increase thickness behind the edge, the width of the edge gets bigger. Take a piece of 1/4" steel and grind a 45 degree angle into the edge. The edge width will be nearly 3/8" wide. Now take some 1/8" stock and do the same thing. Same 45 degree angle. Now your edge width will be about 3/16" wide.

So, if your knife maintains the same SPINE thickness all the way to the tip, and the edge curves towards that tip, AND you maintain a constant edge angle, your bevel width must get larger as you approach the tip. Because the stock 2 inches from the spine is lots thinner than the stock *at* the spine.

Notice that in your pictures, both sides seem to have a nearly perfectly linearly increasing bevel width. Good job Edge Pro! Good job Edge Pro operator. You have maintained a constant edge angle.

"But, but, but, but..." you say, "...my kitchen knives don't do that!" On knives where you don't notice the edge bevel width change, one of two things is happening (or a combo):

1. Distal taper. If you look down at the spine of a kitchen knife, you'll notice that most of them DECREASE the spine (and overall body) thickness as they approach the tip. The fancy words I used above (distal taper) mean exactly that: decreasing thickness as you approach the tip. This compensates and keeps the edge thickness relatively constant, which correspondingly keeps the edge width constant.
2. Variable edge angle. The people that sharpen Old Hickory knives at the factory are apparently pretty darned good at increasing the edge angle as they approach the tip. The factory bevels are usually fairly constant from hilt to tip. When you resharpen them yourself with a guided system (or just good hand held technique), suddenly the tips get really wide. Because you are keeping a constant angle.

I would keep grinding on the tip doing more strokes there than along the rest of the bevel. Of course, I would keep working the entire bevel to blend it in. Otherwise you can get a really weird looking overall bevel. It's best to do some concentrated work, and then do some blending strokes. This is the essence of Secret #5: Selective Grinding.

Next time, if you really want nice even bevels, and you have big thick knife geometry at the tip, you'll want to vary your angle, making it higher and higher as you approach the tip. I occasionally do this when trying to make the edge really pretty.

Good luck.

Brian.
 
Thanks guys, you both have helped me understand what's going on much better.

@Dave
I think I'm doing something similar to canting on my crock sticks. I pull the heel up as I progress down the sticks and towards the tip so the part of the blade that is in contact is roughly parallel with the ground. I think this might be what @Brian calls "the swing" ?

I've also seen people with whetstones increase the angle towards the tip, which is what I believe you are talking about, but the geometry of what I'm doing with the sticks doesn't seem to be exactly the same.

Do you know how to cant as you move towards the tip on an EdgePro?

@Brian
Very helpful lesson on blade geometry. I picked it up again and could instantly see what you were talking about. I'm nervous about the stone rolling off the tip when I'm focusing on it so I try to not let more than 1/2 the stone go past the tip but it's starting to put a nice dip in the stone. Any suggestions on keeping the stone from rolling over/off the tip on an EdgePro, especially with a strange tip like this Gerber? I'd like to keep the tip crisp if possible.

Also, several points in your seven secrets post helped me in the past but the deburring options were eye-opening for me.

Thanks again!
George
 
JorgeSparrow said:
I'm nervous about the stone rolling off the tip when I'm focusing on it so I try to not let more than 1/2 the stone go past the tip but it's starting to put a nice dip in the stone. Any suggestions on keeping the stone from rolling over/off the tip on an EdgePro, especially with a strange tip like this Gerber? I'd like to keep the tip crisp if possible.
Click to expand...

I've actually never used an EdgePro. But you have the correct idea. Which is to stop the motion on the stone before the tip "scrapes over the edge and falls off the stone". That leaving the stone action is mostly what rounds over a tip.

This might seem obvious, but I missed it for a LONG time: Look at the tip. Look at it closely. If you have a magnifying glass, loupe, or even reading glasses, use those to get a closer view. The tip should mostly be straight lines leading to a point. Do you see roundness anywhere? If so, that roundness needs to be removed in order to have a sharp tip. In your case, I would pay a lot of attention to the edge side of the tip: The place you are grinding. If you over grind at the tip, your nice straight line leading to the point will begin to round over, or lean backwards away from its intended path. On the other hand, most "used" tips that I see are round at the tip just because they have been used. In those cases, I need to grind the roundness off, leaving behind straight lines. (or mildly curved lines that flow from the original edge)

Appling sharpie to the edge *all* the way to the tip really helps too. If you're like most sharpeners, you're going to notice that the sharpie at the *very* tip doesn't get removed. It's just a matter of grinding at the proper angle until it gets removed. Or, more importantly, until the tip is formed of straight lines with a very narrow apex where they come together. That's a sharp point, every time.

Glad my posts, including the 7 Secrets have helped you out. :)

Brian.
 
BucketStove,

Thanks! I'm a little embarrassed that you sent me a link to the manual that I should have found myself but Thank you! It has lots of info I needed!

Best,
George
 
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