Can't get burr with 600 grit : Edge Pro

B

Bo-dacious

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Aug 13, 2016
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Hey guys, I've had my edge pro for a couple weeks and I've made some knives push cutting sharp. Now I'm sharpening my brother's thick 30+ degree bowie and I'm having trouble. I managed to get burrs at 220 grit but now that I've moved to 600 I can't for the life of me. I've done hundreds of strokes and I tried raising the angle a hair. Nothing's working. On a previous attempt I got it to at least roughly cut paper but this time it won't even cut into it at all. I'm doing everything as the videos show.

Is there a certain reason I can't get a burr? What should I do?

Is it not getting sharp because it's so thick? Or is it simply because I'm not getting burrs?

Also, is Paper cutting the be all end all? Do all my knives have to push cut paper if I'm planning on having a business? Because it cuts other things very easily. What's the reason behind that?

Lastly, the angle arm on my edge pro is getting stuck. When it's moved over to the right and down like when sharpening a tip, it catches on something in the pivot and it slows me right down. I have to move the knife so the tip is like 3 or 4 inches from the table for it to stop. Has anyone else had this problem?

Thanks guys,

Bo
 
Might be the thickness of your bro's Bowie is outsized for your EdgePro. I sharpen freehand (with a guide sometimes) and raising a burr on 220 grit (DMT ultra-coarse) works for me; then I finish on the 600 (DMT red). Can you try freehand with your setup?
 
Are you compensating for the differences in thickness between the stones? And are you using the "Sharpie trick" to make sure you're actually hitting the edge apex, or are you just assuming you're hitting it because you're not changing the angle of the arm from stone to stone?

On the business front you should get used to the idea that most, if not all, people will expect a professionally sharpened knife to shave hair and push cut paper. If you're not up for that, you should probably re-evaluate professional sharpening as a business venture.
 
Albertaed: what do you mean? Like go from the ep to a bench stone? I'm trying to avoid bench stones. I feel I spend more time soaking and levelling than I do sharpening. It's just how I feel. I am open to changing that though. But have you ever had burrs at a low grit then went to a higher grit and couldn't get a burr?

Peters84: Ben from edge pro told me a drill stop collar is a waste of time because the differences in thickness of stones is so little. Oh of course I'm using a marker, I always use the marker trick.

Okay yeah I'm not against making the knife that sharp I just wanted to get an idea of whether I have to or not. Also, I've been told by many people that some knives should be less sharp because a toothy edge is advantageous in some cases.

Thanks guys,

Bo
 
Bo-dacious said:
Peters84: Ben from edge pro told me a drill stop collar is a waste of time because the differences in thickness of stones is so little. Oh of course I'm using a marker, I always use the marker trick.

Okay yeah I'm not against making the knife that sharp I just wanted to get an idea of whether I have to or not. Also, I've been told by many people that some knives should be less sharp because a toothy edge is advantageous in some cases.
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I think there are a fair number of people who would disagree with you about the drill stop collar. Experience will teach you whether that's correct or not. Since it costs all of $3 maybe you should give it a chance.

Sharp and toothy are not mutually exclusive. I have several knives in S90V and S110V which are sharpened only to 300 grit, but will push cut receipt paper and shave hair. This is not to say I'm an exceptionally skilled sharpener, but to illustrate the point -- Toothy is a type of sharpness, not a lack of it.
 
I would be sure to use the sharpie it should give you feedback and show you where your stones are hitting ... it may be the knife just needs the edge reprofiled to a lower angle ... and needs more work from coarse stones to thin it a bit ...
 
I looked at the apex of this knife and it reflects a very tiny amount of light. This means I should go back to the lower Grit, right?

Peters: how do you get a knife so sharp at 300 grit? Okay, I will try the drill stop collar.

Jj: okay, so go back to the 220 grit and try sharpening it again?

Thanks,

Bo
 
The drill stop collar will lend a level of precision you can't hope to match with just the marker.
The stones vary quite a bit after a bunch of use. The coarse stones wear a fair amount because they are doing a lot more work. The finer stones only refine an already sharp edge and so hardly wear at all.

I have used the drill stop collar from the beginning and it is a good solid datum to have. Being a metal worker from the time I could wedge an old vise with a pipe through it and bend stuff (~six) the stop makes a lot of sense to me.
I did wind up buying a higher quality one than I got from Edge Pro. I forget what the short comings were . . . I think the one I bought fits the post more precisely and takes less turning with the allen key.
 
Wowbagger: yeah, I'm going to get one but isn't it just as good to mark the edge every grit? It still means I'm on the right angle doesn't? I mean it's slower but It seems it'd be at the same angle. So unless I'm wrong and that's the problem, has anyone else had this problem of getting a burr on 220 but not on 600 or 1000?

Thanks for the help,

Bo
 
Every time you doing something always try to use some logic:
If you are not getting a burr with 600 stone ( which is course enough) it means you are not hitting the apex (up the angle). Some steels tend to form a big burr some may form a tiny one, but you should get one.
If you are getting a burr with 220, paint the bevel with a marker, make a few strokes with your 600. Take a 20X loupe and check what is going on. It may be that the very tip of an apex is untouched.

Sharpness is a very indefinite term. BUT both polished and coarse edges should push cut thin paper and shave hair. Just polished one will do it easier and more comfortably.
 
M-S-T said:
Take a 20X loupe and check what is going on. It may be that the very tip of an apex is untouched.

Sharpness is a very indefinite term. BUT both polished and coarse edges should push cut thin paper and shave hair.
Click to expand...

This for sure ^
very sound.

Wowbagger: yeah, I'm going to get one but isn't it just as good to mark the edge every grit? It still means I'm on the right angle doesn't? I mean it's slower but It seems it'd be at the same angle.
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As M-S-T said :
It may be that the very tip of an apex is untouched.
Click to expand...
 
I have encountered issues described below during my learning of Edge Pro.

(1) You might have actually failed to detect a burr at #220. If you use tactile sensation to detect it, sometimes rough surfaces created by a coarse stone hinder the detection. If this was the case, it is possible that you might not have hit the apex even with #220.

(2) The burrs created by #220 were too large and not removed properly by the #220 stone. The #600 stone was too fine to remove them. Your edge should be able to cut paper cleanly or even push cut it after #220. Also, you may want to use the #400 stone in between.
 
Go back to your most coarse stone. I would go to the 120, not the 220. Make SURE you have a burr, full length, on each side. Then remove it carefully. Even at 120 it should slice cut paper; probably even slice cut phonebook paper.

I think you probably just "kissed" the apex a few times at 220; probably due to variations in how you were holding the blade against the table. Or, as someone else said, maybe your burr detection technique tricked you and you didn't really have a burr at all.

If you have reflected light, then that part of the blade is not sharp and not apexed. There's a slim possibility that you have a huge folded over burr there. Drawing the blade through end grain wood or perhaps a cork would tell you if that was true. The drawing through should strip off some or all of the burr *if* it's there.

This time, when you form a burr, be very very sure you have one. Make a burr big enough to catch your fingernail on. Then you'll be totally sure you have it.

You might go back and read secrets #6 and #7 of my Seven Secrets. There's some info there that might help you out. Or not.

Good luck.

Brian.
 
M-s-t: yes, I use a marker and I increased the angle slightly and I still didn't get a burr. I will look with a loupe when I sharpen it this time. I reprofiled the edge from 32 to 23 degrees. That should help right?

Wowbagger: I'm definitely going to check that closer this time.

Miso2: I use my Fingernail and can detect a burr at 1000+ grit but I feel I may have not apexed it properly. The edge reflects a tiny amount of light. Is it possible that I DID get a burr but its still not apexed? Or is it definitely apexed if I got a burr at 220?
If i can't get a burr at 600, I'll try using 400 first. So it's possible that the 600# wasn't course enough to make a burr after the 220#?

Bgentry: maybe, but this time I reprofiled the edge so I should be at the right angle, right?
I'm quite sure I got a burr at 220. It feels like every other burr I've raised.
I'll try running the knife through a piece of wood this time.
I will go back and review those secrets.
I have a lot to try now.

Thanks a lot for the help guys,

Bo
 
I almost forgot that you are using an Edge Pro. I've never used one, so I just reviewed a video on the drill stop collar.


If your 220 and 600 grit stones are noticeably different in thickness, this might be your entire issue. Maybe.

Brian.
 
It shouldn't be the problem, I wouldn't think, if he's actually using the Sharpie again when he goes to the next stone, unless he's applying too much pressure when testing to see where the new stone marks the bevel and ruining the previous edge as a result.

Maybe I'm missing something. But I agree the drill stop collar is a good tool to have in the arsenal.
 
Okay guys. I was using the 1/2" stones but I switched to the 1 inch stones and the recurve was such that they worked just fine. I thought it was too aggressive but I guess not. So I switched stones and went to the 120 and reprofiled the knife from 32 to 23 degrees. I think I stated that already. I tried the 600 after the 220 and I was able to get a burr so I continued. It worked. I got the knife to push cut paper. What a relief! Thank you all who helped me. I really appreciate it.

I still don't know why I couldnt get a burr on the 600 1/2" stone. Do you guys think it was the edge angle that caused that or maybe the 1/2" stone wasn't cutting for some reason?

Let me know what you think.

Thanks everyone,

Bo
 
PeterS84 said:
I think there are a fair number of people who would disagree with you about the drill stop collar. Experience will teach you whether that's correct or not. Since it costs all of $3 maybe you should give it a chance.

Sharp and toothy are not mutually exclusive. I have several knives in S90V and S110V which are sharpened only to 300 grit, but will push cut receipt paper and shave hair. This is not to say I'm an exceptionally skilled sharpener, but to illustrate the point -- Toothy is a type of sharpness, not a lack of it.
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The drill stop collar is worth a million bucks. I've used it for yrs...perhaps Ben is pushing his own stones and forgets that some of us will use a WIDE variety of stones with the Edge Pro. I have one diamond stone that is about 3" wide and 6" long and 1/4" thick or so, and I use it to whenever I need to hog off a bunch of steel in a hurry...redefining the edge angle... Many of the stones I use are NOT Edge Pro products, but I'm very happy with them. Any stone...a wide range of thicknesses...and the edge collar makes it easy to change the stone.
The collar works like a champ...believe me, sir.

Toothy is a type of sharpness, not a lack of it. Agreed. I often stop after using my 320 grit stone, and my edges will push-cut Yellow Pages (0.002" thick) all day long. A higher grit will aid in "push-cutting" whereas the lower grit is much more useful in a draw-slicing motion...more of a hack-saw blade edge in miniature.
 
Sonnydaze: ok yeah I'm going to order one when I buy the scissor attatchment.

Yes I know that toothy is a type of sharpness but it's not as sharp as polished, right?

Do you guys know of any good stones that leave a better finish than the 6000 tape? I want a super fine finish just in case someone wants it. I'm not sure if you're able to tell Me I keep forgetting that rule. But if you can I'd love to know.

Thanks guys,

Bo
 
Bo-dacious said:
Yes I know that toothy is a type of sharpness but it's not as sharp as polished, right?
Click to expand...

Well, what is sharp? Perhaps that's too abstract of a discussion point. Let me give you some examples.

A coarse sharp edge should be able to slice cut and (limitedly) push cut paper. The cut will be loud (sound) as compared to a highly polished edge. But it should do it. It should not hang or tear. If it does, it usually means you have some burr remaining. A polished edge will tend to push cut paper better, easier, and much quieter.

In fact, polished edges excel at all kinds of push cuts: Whittling wood, and that kind of thing.

For slicing tasks, less polished edges tend to do better. This is because the "teeth" in the edge hook into the media being cut. This is particularly obvious when you are cutting something that is slick or slippery. Zip ties, fish, and blister packs (plastic packaging) are all examples where coarse edges usually work better.

The key thing to recognize here is that even a VERY coarse edge can be super sharp. Sharp enough to do a little hair shaving (though not very well). Sharp enough to zip through cardboard like a demon.

Polished is just one end of the sharpness spectrum. It's the easiest to demonstrate because more of the "sharpness tricks" are done with polished edges: Shaving hair, cutting paper in circles, etc.

If your coarse edges can't slice cut paper or easily cut cardboard or other media, they probably just aren't apexed all the way, or they have burr remaining. Coarse can be very sharp when done correctly and completely.

Brian.
 
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