Grinding Final Sharpened Edge

Peter Atwood

Peter Atwood

Joined
Oct 26, 2000
Messages
2,468
I haven't seen too much on this topic. In fact it is often just sort of dismissed, but I'm wondering how other makers do it.

How exactly do you put the final cutting edge on the knife?

Do you grind it with the belt grinder?

What grit?

Edge up or down?

Using a jig for precise control of the angle?

On the platen, wheel or slack belt?

Do you use a charged hard felt wheel for the absolute final sharpening?

A stone or rods?

Are these procedures different for Talonite or different steels?

Thanks guys! Any light you all could shed would be interesting.
 
Peter-

I think the first thing is to get a thin edge to begin with.

Once the knife is completely done other than the edge, I use the belt sander. I set my Burr King up with the 3 wheel attachment and use the slack portion of the belt. I use the part just behind the 2" wheel, so my point is I use a spot that has a lot of tension but is still slack. I have more control this way.

With the knife edge facing me, I draw the knife across the slow moving belt like I'm drawing it across a sharpening stone.

I start with a coarse belt and hit it once or twice per side. Then a worn 120 for a pass or two, then a worn 400 belt (this will form the fine "wire edge" burr. Finally I do the same with a super super worn 600 grit belt charged with buffing compound.

This makes a very clean edge that from my testing will cut quite some time. Of course edge geometry is a hugely varying subject...so ask ten makers and get 8 different answers.

I would like to try some different stones and such, but this method is quick, easy, and seems to work very well. If someone can show me a better way, harder or not, I'll definitely try it.

Good luck Peter,
Nick
 
I use the vertical flat platen of my Burr-King VS grinder running at about 10% power,start with a worn 120 grit belt until I get the wire edge,switch to a 320 grit worn,make a couple of passes per side,go to a hard felt wheel on my buffer loaded w/green rouge,hold blade at a 45 degree with wire edge up,make a light pass on each side to knock off the wire edge.It will shave,and it lasts.I sharpen edge down.
 
Excellent! We already have two differing methods. I'm hoping to see a lot more on this from others......

MJH, you hold the blade edge up on the hard felt wheel? Isn't that asking to be grabbed and stabbed? Or am I reading that wrong? At Tom Anderson's shop we used the felt wheel but held the edge downwards.

Both of you mention using slow speeds on the grinder. I have been using full speed ahead because I don't have a variable speed yet. MY results have been decent but what exactly is the benefit of a slower speed. Seems like it would not be the way to go.

If you already have a thin edge which I always seem to, then is it really necessary to use a coarser grit belt to start? I've been going straight to 400.
 
Worn out 180 grit on a 14" contact wheel and strop on a hard cardboard wheel coated with green stainless steel cut and colour compound. All is done edge down.
 
peter i use the slack belt beteew the 2"and 5" on my hard core. i start with a stiff 120 grit after a couple of passes i go to a 400 grit repeat. this is edge up. then i go to a loose muslin wheel loaded with fabulustre compound, this is done edge down the muslin wheel takes the wire or burr off the edge. i tell you working out a way to put the final edge on took a lot longer than i thought it would when i started making knives.
 
Peter,I said hold at a 45degree angle with the wire edge up,what I mean is,the side of the blade with the wire edge is foremost,or first to get buffed,edge DOWN.I would never put a knife to a buffer edge up.Guess I should have been more specific.
 
This thread produced some interesting answers and most of them seemed to be different. But I'm not convinced that we heard from everyone and there's probably more out there. So C'mon Ya'll!:D Let's hear from more makers......
 
I flat and convex grind, just about all my knives. For a flat grind, after HT, I run the edge against the platen using a worn 400 or 600 belt. I then finish up on a paper wheel with green rouge and buff.
For convex grinds after HT, I slack belt with the edge up using 400 or 600 used belts. I then go to the buffer using a med cotton with green rouge. I always strap my edges using a leather belt and white rouge.
KEN (WWJD)
 
Nick, when you say "thin edge", exactly how thin do you mean? I shoot for an edge about 1/32" thick, is this about what you guys mean? Sometimes I think this might be a little too thick to start from.

Anyway, I start with a fairly sharp 400 on the slack belt, move to a worn shiny 400 to get the wire edge, and take that off on a felt wheel with green chrome. I work in a stiffer section of the slack belt too.

This produces the "scary sharp" edge Bruce Evans and others were talking about a while back, but as a result of that thread I'm beginning to rethink whether that's always best. I think it is best for show and tell, maybe not for a working knife.
 
What I'm finding interesting is that apparently none of you are using any kind of jigs or guides to sharpen your blades. Therefore all the anal retentive talk that we hear in the other forum sections about edge geometry doesn't mean much when it comes to custom knives. That is, there is no way you could precisely control those angles in a hand sharpened blade.

I've heard a lot of fussing over the exemplary sharpening methods of Tom Mayo. I wish he would chime in here too.....Hint hint.;)
 
peter finer grit belts work better at slower speeds. also it keeps the heat from building up which can burn the tip or mess with the heat treat of the steel. i do a lot of sharping of production culinary knives and a slighty used 220 grit buffed on a loose cotton wheel with fabuluste leaves a very aggressive edge. chef's love it.
 
Peter,
I hollow grind on a 10" wheel and take the edge down to .020-.022.
I sharpen on the same 10" wheel, edge up, starting with a 320 grit then 600 grit. Next, I knock the wire edge off with a hard buffing wheel and white compound edge down.
I don't use a fixture to grind so I figure I don't need one to sharpen it with:)
 
220 grit slack belt to a wire edge. Straight to hard cloth buff with compound. One pass each side. Shaves every time. All edge down.
 
I do some sharpening for local food service places. My favorite is a pub where I get paid in Newcastle Brown Ale!
Depending on how dull I may start with 120 grit belt. I go ahead of the wheel for a slack belt 'apple seed' type edge. Then I move through grits to 400 usually before moving to the buffer. I've found that the stainless polishing compound works better on most restaurant knives. If you want to work on comersial knives be carefull, some of them are so soft that you can ruin them by breathing hard!
I bought a paper wheel sharpening system. The first time I used it I thought I had found the best thing since pockets on shirts. The second use was less satisfactory and the third was useless. It seems to require more maintaince than I'm willing to give it.
IMHO, Lynn
 
My technique is basically the same as Nick Wheeler's. I also use a Burr King 960 with the knifemaker attachment, and grind, edge up, just below the 2" wheel. I start with a 60 micron belt (approximately 220 grit), and follow that with 60, 45, and 30 trizact belts. Finally, I strop on a piece of belt leather glued to a flat board, and charged with buffing compound.

My ground edge is about .025" before I put the final edge on, and using this method does indeed give me a micro convex/cannel/appleseed edge right up to where the hollow grind begins; a distance of perhaps .050".
 
Not my idea, but Dan Westlind gave me a lesson on sharpening. He uses the sharpening wheel kit, available from K&G for $16.75. He put the wheels on an old motor and within a minute had a dull blade razor sharp. Nice thing about it is it is always set up.:D dlee
 
Hmmm. I guess i have a different approach too, because I dont really consider getting that final bevel a separate step on the grinder. I finish grind after HT, ending up working longways over the contact wheel (so the grain is longways) then go to the abrasive paper on a leather covered block. By this time the edge is plenty thin to go directly to a medium coarse grey synthetic stone to establish the secondary bevel. One I get a burr ALL along the edge working both sides, I got to a red rouge impregnated leather strop and work the burr off. patience is required for this. After that a light touch up on an arkansas stone will do it until the edge gets quite worn. I cant imagine going to the belt grinder to put that last little bevel on the edge. As they say in shooting, "You cant make up for missing by missing real fast." My usuall test for keeness is whisking little bits off that nasty yellow import re-cycled cardboard. It crushes before it cuts unless you have a keen edge. My blades may be a little softer than what you folks are describing needing buffin, etc. Plus they are carbon to steel, nothing fancy. I like my blades just barely soft enough to work well with a butchers steel. Anything harder in a big blade is, in my humble opinion, likely to be lacking in toughness.
 
I'm just amazed at the variety of answers we're getting here. It would seem that there are quite a number of ways to achieve a similar end. Makes me feel a little better about the way I've been doing things and also tells me that there really doesn't seem to be a firm "right or wrong" way to sharpen a blade. Let's hear some more!:)
 
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