Pointers for my Tips?

[Matt]

Hey All,

I’m continuing to progress with experience and knowledge with every knife I sharpen.  I have found some great results so far, but one area that I’ve been having problems with are blade tips.  Particularly tips that are curved at the end like a boning knife.  I’d like to hear if there’s any advice for helping me create sharp curved tips?  That’s basically an area for me that remains somewhat dull.  I feel the area has improved by my sharpening with the wicked edge, but it does not equate to the straighter parts of the blade.

Thanks and appreciate the feedback and advice.

[airscapes]

I only do the few kitchen knives my wife uses, but recently I have stopped trying to do the entire knife in one vice position. I do most of the straight part into the curve all the way to the end then reposition so the  end I have not done is in the center of the vice as level as possible then fish that up blending the 2 areas.  This is of course on a touch up, harder to do if you are starting with reprofiling.   When doing the complete knife in one mounting position finding the sweet spot is key but many times you will need to remove more metal on the dip due to the change in angle so to speak as the end curves down and that part of the knife get lower

 

[Brewbear]

I usually sharpen the straight part of the blade and reposition the knife in the vise to sharpen a curved tip end if the curvature is very significant. Sharpening a blade in sections works well for big kitchen knives (or machetes) but you have to remember to blend the sections.

[Marc H]

Now that you’ve gained experience sharpening a few knives with your W.E. it becomes easier to recognize areas on the knife edge that are more challenging to sharpen.  The extremes of a knife, the tips and the heels, are often the edge portions where it’s more difficult to match the flat sharpening stones to these blade contours.

Dividing the clamped knife’s length to sharpen it in several smaller portions, then blending the sharpened portions at the end, often helps.  (I sharpen every knife like this with the blade broken down to smaller portions then blended).  Concentrating on just the curved tip portion alone, is helpful, also.  Try keeping your sharpening strokes directions more perpendicular to the knife edge.  Even if your stone’s motion becomes almost horizontal relative to the sharpener’s base or the table top.  Rotating the sharpening stones around the guide rods in order to maintain as full a flat contact patch between the stone’s face and the bevel portion you’re working on is helpful.  Depending on the curved shape of the knife edge, only a portion or portions of the stone’s flat face may be able to make contact with the bevel.  Not the full width of the stone. This is easy to maintain when your sharpening the flat portion of the knife edge.  When sharpening the tip be sure to follow through with your stone strokes so you move the stones straight away as they’re lifted off the tip.  Avoid curving or wrapping the stones over or around the knife tips.  This can round off a sharpened knife edge at the tip.

That said, the knife edge of any knife sharpened for the first time with your W.E., (a fixed angle) sharpener, will undergo some minor amount of blade profiling.  This may slightly reshape the knife edge by removing a small amount of steel at the blade ends as the knife is conformed to your W.E. sharpener.  This may occur, ever so slightly, even with knives clamped in their best “sweet spot” sharpening position.  With each subsequent touch-up if the knife is positioned then clamped the same way the stones will match right up everywhere along the knife edge.  No additional reprofiling or extraneous steel removal will occur.

Sharpening experience will help you to recognize these issues from the get go.  You’ll intuitively know upon initial inspection which edge profiles will be challenging.  It’s better to spend a little more time with your sharpie at the onset to find your “sweet spot” before you start sharpening then after you’ve gotten started.  Try rotating your knife to position it slighly handle down and tip up.  Also, try sliding the knife in the jaws so the tip is closer to the vise, or maybe with the tip slid further forward.  It may require a combination of these actions.  It doesn’t matter what clamping position you find you need to use as long as you can sharpen the knife well and record and recreate the clamping position again later.  Even with your best efforts, you may not match the bevel perfectly.  At least you’ll find the best “sweet spot” position with the least amount of steel removed this first time sharpening the knife and this initial profiling.

If you find your scratch pattern is coming up just short.  That is, it’s reaching just slightly below the knife edge, leaving the apex untouched.  Keep at it with your stone work.  You’ll reach the apex in short order with a little more effort.  Then the edge will be reprofiled and it’ll match right up for your future touch-ups,  with this same clamping position.

If all else fails, repositioning and reclamping the knife, during the sharpening session, in order to sharpen it in two phases, as suggested by “airscapes” and “Brewbear” is certainly a viable option and will work well when if the portions are blended together.  Some extreme knife shapes or profiles leave you no choice except to sharpen the knife in sections.

Whatever you learn you need to do notations in your sharpening log will help you for touch-ups.

Marc
(MarcH's Rack-Its)

[tcmeyer]

I infer from Matt’s post that he is looking for tips on how to avoid rounding off the tip as he moves the stone beyond the end of the blade.  This is as opposed to producing a sharp edge along the last half inch of the blade.  For me, the key here has always been to “follow through.”  As you move through the area of the blade tip, do not allow the stone to rotate as it leaves the tip – keep the face of the stone parallel to the edge.  You can also improve things by starting your stroke at the tip.  This is a point where you instinctively hold the stone parallel to the edge.

As a matter of good technique, you must learn to let the stone align itself to the blade’s edge, while not allowing the stone to turn uncontrollably.  Feel the alignment of the stone to the blade and then maintain it.

2 users thanked author for this post.

Wicked Now., Brewbear

[Marc H]

Matt wrote:

…one area that I’ve been having problems with are blade tips. Particularly tips that are curved I’d like to hear if there’s any advice for helping me create sharp curved tips? That’s basically an area for me that remains somewhat dull.

 

Marc
(MarcH's Rack-Its)

[Matt]

Good Day and thanks for everyone’s response on my question.  I had a feeling that due to the curvature of the boning knife’s tip, it would require additional reprofiling or that I had to reposition the knife within the vise.  Thank you for the tips on blending the different sections.  I imagine when Marc H says to keep the stone perpendicular to the knives edge, that angle would drastically change while moving along the curvature of the tip?

 

 

 

[Marc H]

Matt wrote:

I imagine when Marc H says to keep the stone perpendicular to the knives edge, that angle would drastically change while moving along the curvature of the tip?

I’m moving the sharpening stones along the knife in a manner to put down a scratch pattern that is for the most part perpendicular to the knife edge.  On the flat or mostly horizontal portion of the blade, the perpendicular motion for the stones on the guide rods are almost straight up and down.  As I move across the edge approaching the downward curved tip to move the stones perpendicular relative to the knife edge the rods will be angled away from me.  At the tip end of the blade for the almost round curved knife tip, for a perpendicular scratch pattern, the stone motion and the guide rods are almost horizontal.   There are times when my scratch pattern is still crossing perpendicular to the knife edge but the stone on the guide rod is crossing the edge at a different angle.  As I’m doing this stone work I’m continuously walking the stone along the edge bevel to prevent too much stone work in any one place. This blends the sharpening effort and the scratch patterns evenly along the knife edge.

While I’m keeping my strokes mostly perpendicular to the knife edge portion that I’m working on, this doesn’t effect or change the bevel’s set angle.  Whether your sharpening strokes are edge leading, edge trailing, scrubbing up and down, going side to side or even round and around, as long as the sharpening stones are held consistently in flat contact against the knive’s bevels, the set angles will remains the same.  By sharpening a knife’s length in smaller portions I have more control to keep the stones flat on the bevels and my set angles uniform.

This method is what I’ve found works well for me.  Other’s have different ways to attack it.  Irrespective of the type of sharpening strokes you are using, (i.e., edge trailing, edge leading, or sweeping strokes), to try to keep that stroke continuous and uniform down and across the entire knife’s length, when you reach the downward curving tip your sharpening strokes will be going almost sideways across the tip bevel.  By the time they reach the tip some users may run out of stone length to finish the sharpening stroke. They find themselves reversing or backing up the stone’s direction as they look for more stone to negotiate the tip.  This situation can occur just the same whether starting the sharpening stroke at the tip or with the heel.

This is the same common issue W.E. users have when sharpening a relatively short bladed knife,  like an EDC.  The knife edge is short enough that it may be sharpened heel to tip in one continuous sharpening stroke.  With the stroke approaching the tip end, they find themselves trying to figure out how to make that stroke work right, while it’s still in motion.  As the knive’s shapes change at the tip, this continuous sharpening stroke doesn’t cross the tip bevel in the same way that sharpened the flatter portions well.

Think of it this way…like you’re running up stairs.  You have a good rhythm going.  All of a sudden you reach the third step from the top where the steps oddly change height, angle and pad depth.  You’re caught flat footed trying to figure out your footing in the middle of your running motion.  You sort of stumble trying to keep the rhythm you had going.  It doesn’t matter even if you know the step change is coming.  It still disrupts your momentum as you adapt to the change.  The same sort of thing happens as the knife tip curves down at the end of your moving sharpening stroke.  You’re left trying to figure it out, how to go across it, in mid-motion.  It’s hard to sharpen the entire edge with a rhythmic continuous stroke when you meet the downward tip.  The curve effects your strokes and your results.  This is why I do it as a separate portion then blend them together.

Another common issue to consider at the same time is that which “tcmeyer” wrote about above.  It’s a common occurrence to wrap the stones over and around the knife edge as you reach the end of your sharpening stroke.  By following through as Tom suggested, you’re lifting the stones up and off the knife tip as you use a continuously moving sharpening stroke.

Some new W.E. users may stop the stone dead, smack in the middle of the tip, before the stone has passed clear off it.  Other users tend to push the stones inward towards the blade’s center-line once the stones pass off the tip.  That is the same direction of their applied stone pressure against the knife bevels.  They can roll the stones over the sharpened tip bevel as the stones are rotated inward around the guide rods.  By concentrating on keeping your stones in consistent flat contact with the bevels while using an off and away stroke direction in a continuously moving follow-through, rolling over the tip bevels can be avoided.

Marc
(MarcH's Rack-Its)

2 users thanked author for this post.

Wicked Now., Steve

[Anonymous]

I’m a 130 owner having similar question as OP about options for getting tips sharp.  I’ve seen this before, not new to sharpening but new to W.E. and wondering best options to get that last 1/2″ or so of the tip sharp on a deep belly curve.  I have a current 3.5″ folder I’m working on, the whole rest of the edge even belly curve is beautifully sharpened with a nice bevel about 14 dps. But the last 1/2″ of the tip, there’s a very tiny bit of the old edge where my new bevel didn’t get all the way down to the old edge, so it didn’t create a new apex.  It’s not bad, you can barely see it, the old edge almost looks like a micro-bevel that last 1/2″, and looks like it wouldn’t take much to fix. But it’s keeping the very tip from being as sharp as the rest of the edge.

What are the possible techniques to resolve this issue on W.E.?

1. Reposition the knife in clamp to focus on the edge.  Ok I see that option above, inline, will consider that.  Are there also downsides of this approach I should think about?  One that comes to mind–won’t I have to do this every time I sharpen the knife in the future, so I’d need to record 2 sets of sharpening position data?  Or is this a one-time operation?
2. Do some concentrated up-down strokes right on the problem area.  For example, go back to a lower grit, and do maybe 10 up-down strokes per side at a time, until I can hit the new apex that last 1/2″, then draw a burr, and finally, blend it back in with full-blade strokes.  Is doing this a bad idea, is it likely to bungle up the edge?
3. Others?

[Anonymous]

Needed to rotate the knife handle downward in the clamp, so that the tip is higher than the straight portion (for this knife with a deep belly curve–more optimized sweet spot).

1 user thanked author for this post.

Marc H

[Author]

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