Profiling the edge - - - -

R

rlinger

Joined
Mar 29, 2002
Messages
4,591
I am frustrated at the amount of time it takes me too profile and sharpen the edge upon completing a knife. Yesterday it took me from 3:30 to midnight with only about an hour break in between. I try to grind the bevel to an edge of about 20 mil +/- 5 mil before heat treat, finish the knife, then put the edge on it. I do my edge by hand because I don't trust my judgement using a belt grinder to get it consistant about its entire length and at the angle I want (I'm one of those guys that can not even sharpen a knife on a wet stone). I have to use guides to get it right.

Unless I am warned by those knowing better, I am going to profile my edge to a couple mil thick at its apex before heat treat. That will be more hazordous when buffing but I've had it with killing myself profiling these hard-ass edges.

EDIT: Maybe I better make that about 5 mil instead of only a couple mil.

Roger
 
Roger,
Like I told MikeO when he started...Practice, practice, practice. He sharpens better than me on the grinder now. 2 minutes at best. :)
 
Roger,
It's insane to do the initial edge by hand(well, for me anway). Unless, of course, your into that kind of self abuse.:D
What I did was to grab up some cheap ass kitchen knives at a thrift store, flatten the edges on the grinder and practice, practice, practice getting that initial edge bevel on. With a little practice it gets easier and you learn to make swift, smooth passes at a consistant angle that won't damage the temper. That beats the pants off doing it by hand. Unless, of course, your into that kind of...

Maybe you can make a jig that will aid in keeping a consistant angle as you make passes on the grinder? I don't know...

I just taught myself the method above and it works for me. Good luck!


All the best,
Mike U.
 
I was afraid some one was going to say something like that. Okay. If I'm going to make knives I better properly learn all steps of it. UGH.

Roger
 
Oops! Sorry guys. I was typing when Kit posted and posted when Roger did too.:)
 
Well now that's an idea. I bought one of those Wok things that came with a bunch of the best looking cheapest ass knives you could dream of. I can butcher those all I like to practice with.

I almost didn't post this thread. I'm glad I did.

Thanks.

Roger
 
Rlinger,
Any chance we could see a pic or two of the knife or knives you're having difficulty with? I'm curious.

It takes me a quite awhile to sharpen by hand if I'm putting its first edge on. Hours. Sometimes on and off again over a few days in some cases. But I rarely sharpen strictly by hand anymore. I use it only for special cases or mix methods occasionally. Usually, I do all the grinding and edge profiling these days down to its burr right on the grinder. Then I just strop by hand. Its the perfect combination for me and is as good as anything I can do entirely by hand (on those that allow the option). But that in considering me, my tools and my knives. Some thoughts to consider perhaps.

I forced myself to get good on the grinder cause I knew with practice I could match my hand skill and be more efficient. It worked. :cool:

Jason
 
Jason,

Pictures of the knife I used in my example above will be posted on this forum tomorrow eveniing (EST). I had to work today and couldn't take pic's. I have to wait for sun light now. Sometime tomorrow. However, all my knives so far have been sharpened from start as I described above. It has been the only process I have truely dreaded. I am going to practice what Kit advises and will start on those cheap things that look like knives that came with that blasted Wok thing - just as Misque advises.

Its a D2 Persian skinner with lots of curves and some mammoth bone in the handle.

Roger
 
Hey Buddy,

I'm gonna open my big amature mouth again.

1. I can't sharpen on stones
2. Even with jigs I don't like my edges
3. I have to hold the blade level
4. I have to have the belt (or wheel) running away from me

Given all that here's what I do (actually this is based on how I used to do it with paper wheels).

I set the platen at the angle I want - tilted way back. It's about 20 degrees off level. Then I run the grinder backwards and slow with a 220 belt.

Now you get into a Zen frame of mind - say hoooom, hoooom a few times (That might be just a california requirement). Focus on the ricasso and get it level. Now make contact with the belt and draw it across, pulling the handle back as you get to the belly.

I alternate sides until I raise an EVEN burr on both sides. Then I moved to a 45 Micron re-burr, then 16 micron - re-burr.

Finally I remove the last burr with the paper wheel with white rouge.


I think the point is practice. However, for me I just couldn't do it any other way - no matter how much practice. I can't hold at the same angle twice, but I can hold it level over and over - go figure.

Steve
 
We don't do much of that Zen stuff here in the Mountain state but I get strong vibes from what you write. Tilt the platen to the angle you want and hold the spine perpendicular to the surface of the earth. Sounds easier to me now. I will try to Zen my way right into that.

Thanks Itrade. Turned out to be a good thread for me.

Roger
 
Originally posted by itrade

Now you get into a Zen frame of mind - say hoooom, hoooom a few times (That might be just a california requirement).
Click to expand...

...buncha bean sprout suckin', cut bait eatin', Califor...just sharpen the darn thing! LOL! Just pokin' some fun, don't take it serious!

If there is any way that you can slow your grinder down, it helps. I would be lost without variable speed but step pulleys should work as well. When sharpening on a grinder, it takes very little pressure - especially if running at a fast speed. Keep the edge cool and don't burn it or overheat it.
 
I'm certainly no expert so take this with a grain of salt. I have a Coote also. I like a slightly convex edge. With the grinder running on my slowest pulley with a 220 jflex belt, I hold the knife edge down about 2" above the top of the flat platen. The spine on a 1 1/2" wide blade is about 3/8 to 1/2" away from the belt. This is a pretty acute angle, but the belt will flex such that your final edge is not too acute. Starting at the ricasso, I barely make contact and pull it toward the tip at a medium speed. When the tip gets about to the middle of the belt, I pull the blade away from the belt. On my first ones, I went completely off the edge of the belt, rounding the tip. Do 1 pass on each side untill the burr is raised. Then I use a 400 grit belt. I like a polished edge, so then I either strop by hand on leather with green polishing compound, or run an old belt inside out on the grinder with green compound on it. I think stropping by hand works better for me. Like everybody els said, practice on some cheap knives first, not an Emerson Commander. :rolleyes: Oh oh oh. Something I learned that may be of value to someone. If you're sharpening a recurve blade, you can split a belt down to 1/2 or 3/4" and it makes it easier to make that curve. Also good for shaping curvy handles.

I have also sharpened the same way on the platen when I wanted a flat bevel, but it's less forgiving.

After getting used to the grinder, I would have one just for sharpening, even if I didn't make a few knives. Wanna buy a Sharpmaker?

Have fun,
Steve
 
First things first,When I started making knives I was told that I had to learn how to sharpen them also.I also started out setting the edge by hand,then I seen a guy sharpen one on a belt grinder.He did it in the slack belt section between the wheel and upper tracking pulley.So I went home and tried it.It worked great and the convex edge holds up awesomely.This was befire I has heard of a Moran edge also.
Now you can take the edge down close like you said before heat treat but only with stainless blades,if you try this with carbon you are asking for warped or wavy edges.
What i do now is grind and heat treat then finish grind and as I finish up the finish grind I will convex in the edge to what ever height up the blade I need for the edge I want on that particular blade style.Then when I do my hand rubbed finish I smooth it all together,yes I have a very sharp edge at this point and usually only need to lightly hit it with the buffer or strap.Plus you don't see the little line that gets jumped on your finished out blade.
It work for me,and is just the way I do mine.
The best advice has been given already...Practice,then practice some more.
Bruce
 
Roger - your work is too nice to see you get hung up un this point. so hear goes... I used to just about have a stroke before putting an edge on as I nearly ruined every knife I did (attempted) to sharpen.

My answer basically reinforces the already ecxellent comments by th othet forumites... some stuff I do, too....

He did it in the slack belt section between the wheel and upper tracking pulley.So I went home and tried it.It worked great and the convex edge holds up awesomely.T
Click to expand...


Now you get into a Zen frame of mind
Click to expand...

... on the last quote, I find that focus is as important as anything.

R.J. Martin showed me a method that reflects the simplicity of putting on a good edge: I start with about an .020 edge. Use a 1", 220 J-flex (3M707) in the slack belt portion. I use an attachment on a Bader, but a 1" x 30" grinder with the platten removed will do the same. Edge down, use about a 12 degree angle and when you press (not too hard) into the belt you will see it deflect some. A couple smooth passes on each side at a time.Concentrate on keeping the angle and a smooth seasy pass where you just whisk the tip through at the end. You are done here when you raise a visible burr. I then go to the buffer and with a couple light, edge down passes, knock off the burr.
Result - a shaving sharp edge every time

R.J.'s knives are still the sharpest thing around - he has years of exp. on me and there are other factors here - edge geometry, steel & heat treat, etc. Thing is, though, you can get almost to his level fairly quick -one belt & two operations. This give a "working edge" . If you want to refine it further on the grinder with say, Trizacs down to A16 or the Nortons, you can do a shiney "show" edge - maybe not as sharp but almost.


Have fun, Bob
 
I'll throw in a couple more options...

On a Burr King type grinder, slack belt sharpen in the area just before the belt makes contact with the top of the wheel.

On a Square Wheel type grinder, use the platen and sharpen in the area just before the belt makes contact with the top wheel. I've seen some flip the square wheel platen over and use the slack belt area.

I'm one of the guys that mostly sharpens on a 10" or 14" contact wheel.

J weight belts work best for me.

I use a hard buff with white compound to remove the burr.

I'm the worst hand sharpener that ever lived :)
 
The way a cheap person like me gets pratice is to sharpen the knives for the local pub. Just a couple of beers is what I charge!
I sharpen slack belt. It gives a convex edge that should last longer. I move down to a 30 micron belt then take to the buffer for a couple of passes. Shaving sharp in under 2 minutes.
Beerly, Lynn
 
Sometimes I use only stones and paper to establish the precise edge geometry I want--after heat treat. It is time consuming, but I have WAY more control and am more pleased with the results. Other times I use the belt. The results are certainly good, and it is very quick and easy to get shaving sharp and beyond.

If you go with belts, listen to Bob (R.J.) and use 1" wide belts. My main problem with belts is using 2" wide because they tend to stay high and tight in the middle, but droop at both edges. This results in non-uniform sharpening angles, dinged ricassos, etc. You'll also be getting two belts for the price of one!

John
 
Don't get so hung up on things. You don't have to do it completely one way or the other. I set the edge bevel with my 4X36 and then finish sharpening by hand. With a dead belt (scraped down to just the nylon) with some green buffing compound, I can make it shave, but its still not a great edge. A little work with the stones improves things alot.
Evening up edges is alot easier by hand than completely setting them.

Also, put a strip of masking tape down the blade of your knife to within 3/16" to 1/4" of the edge. That will keep you from scratching it up.
 
I'll just tell you how I do it. On a finished knife, I sharpen on a flat platen, with the belt running in the conventional way, with the edge down. I can judge the angle from the spine better that way.
I start with a 120 grit belt till I raise a burr, making an equal number of passes on each side. I then switch to a 320 grit for a few passes. I jump to a medium felt wheel with green SS compound on it. I put the edge to the wheel at a 45 degree angle, edge down, of course, and the burr side first. I make two passes on each side. That's all. Takes me a very few minutes.
On occasion, I will use the tight slack belt area between the platen and lower wheel(Burr King) to sharpen.
Incidentally, you kind of lost me with the profilling part of the description. Profilling to me, means the grinding of the design from a bigger piece of steel. I hope I am not misunderstanding you here.:confused:
 
You must log in or register to reply here.
Back
Top