Checking for a burr/wire edge

[Todd Simpson]

…..

So it sounds like what you are saying is that you can go edge trailing w/ a micro bevel on a razor, you just have to do a certain number of strokes (say 20-30 vs. just 1-2) to increase the contact area of the apex so a normal microbevel will form?

Either edge trailing or edge leading, the contact area is extremely small and therefore the pressure is extremely high when you first start to micro-bevel. Once the micro-bevel is established, the contact area increases and the pressure can be low enough to abrade normally rather than simply deforming the apex.

[Zamfir]

…..

So it sounds like what you are saying is that you can go edge trailing w/ a micro bevel on a razor, you just have to do a certain number of strokes (say 20-30 vs. just 1-2) to increase the contact area of the apex so a normal microbevel will form?

Either edge trailing or edge leading, the contact area is extremely small and therefore the pressure is extremely high when you first start to micro-bevel. Once the micro-bevel is established, the contact area increases and the pressure can be low enough to abrade normally rather than simply deforming the apex.[/quote]

By God, that actually makes sense to me today. It will result in a slightly larger “micro bevel” but it will be right. and when I say slightly it is all in context of how small it already is ya know?

Would all of this still hold true if you were making a micro bevel with a 400 grit stone to give it some teeth? And then a little refining of the micro bevel with some ceramics after?

[Geocyclist]

Hey Josh,

I am finally getting my head around this one. After your first post I didn’t quite follow but now I understand you are talking about a very, very, small burr.

Would a strop work?
Would it risk rounding the edge?
If the burr is so small it comes off on jeans then this could contaminate the strop for those of us who care enough to wipe the blade down between changing different strops.

I like the felt block. Looks like dragging/cutting the edge straight into anything would accomplish this. Leather, many sheets of paper, a rag, phone book, soft wood.

I would like to see the difference under high magnification as well as see the burr that is removed.

[Josh]

Hey Josh,

I am finally getting my head around this one. After your first post I didn’t quite follow but now I understand you are talking about a very, very, small burr.

Would a strop work?
Would it risk rounding the edge?
If the burr is so small it comes off on jeans then this could contaminate the strop for those of us who care enough to wipe the blade down between changing different strops.

I like the felt block. Looks like dragging/cutting the edge straight into anything would accomplish this. Leather, many sheets of paper, a rag, phone book, soft wood.

I would like to see the difference under high magnification as well as see the burr that is removed.

Yep! Yeah I’m not saying that the burr comes off on my jeans I’m saying that it just flips it. It could probably be better described as a wire edge than a burr.

As clay referenced , This is what an edge looks like when you cut into wood to try to remove the burr – not so good! It just folds the wire edge 180 degrees.

[wickededge]

Hey Josh,

I am finally getting my head around this one. After your first post I didn’t quite follow but now I understand you are talking about a very, very, small burr.

Would a strop work?
Would it risk rounding the edge?
If the burr is so small it comes off on jeans then this could contaminate the strop for those of us who care enough to wipe the blade down between changing different strops.

I like the felt block. Looks like dragging/cutting the edge straight into anything would accomplish this. Leather, many sheets of paper, a rag, phone book, soft wood.

I would like to see the difference under high magnification as well as see the burr that is removed.

Yep! Yeah I’m not saying that the burr comes off on my jeans I’m saying that it just flips it. It could probably be better described as a wire edge than a burr.

As clay referenced , This is what an edge looks like when you cut into wood to try to remove the burr – not so good! It just folds the wire edge 180 degrees.

[/quote]

That burr looks like it’s so fine it could be easily flipped back to the other side and would break off pretty quickly. I’m guessing that flipping it back and forth would make the metal brittle they way that Cliff Stamp describes. Judging by the scale in the image, it looks as though the burr is several microns tall and just a fraction of a micron thick. I’d love to see what’s underneath were the burr to be popped off.

-Clay

[Todd Simpson]

That burr is about 0.4 microns thick. At that thickness, it will break if you stand it up again (on your jeans, a linen strop, or newspaper).
Also, folding a burr of that size will torque the apex and bend it (below the burr) to that side as well. After the burr is removed, the apex is asymmetrical as a result.

A foil-burr that flips back and forth without breaking will be less than 0.1 microns thick, in my experience. A foil less than 0.1 microns thick won’t torque the apex, so there is no harm once they are removed.

[Zamfir]

Awesome stuff here!

So, I sharpen a blade and have the experience of it shaving better on one side rather than the other. Now I can check by stropping on a linen or pant leg multiple times on one side..check it again, repeat on the other side, check it again.. if the sides that save better changes depending on which side I am stropping on my pant leg I know I have a very thin burr or (wire edge).

I am seeing from the above couple posts it is not a good idea to try the wood or felt block..

Now what do I do to fix it using the wicked edge? The paddles would still be set up to the angle of my micro bevel and I thought I had a nice sharp perfect edge..did the above tests and confirmed I have this problem.

What next?

[CliffCurry]

[/quote]

That burr looks like it’s so fine it could be easily flipped back to the other side and would break off pretty quickly. I’m guessing that flipping it back and forth would make the metal brittle they way that Cliff Stamp describes. Judging by the scale in the image, it looks as though the burr is several microns tall and just a fraction of a micron thick. I’d love to see what’s underneath were the burr to be popped off.[/quote]

Refining and removing this micro-wire edge seems to be the question. Thanks to Todd for all his research! Also as he has mentioned, this is a razor, the angles of normal knives are more obtuse and I think this could also effect the behavior and formation of the wire or foil micro flap?

After the burr is folded over to the left side in the photo, I wonder what a whisper light edge leading stroke down that left side with a micro fine ceramic stone would do? Remove the burr and possibly straighten a bit of deformation? :huh:

[tcmeyer]

All the while, I’m thinking ‘holy crap. this is a straight razor!’. If the edge is near foil thickness, how can you possibly apply a micro-bevel? Wouldn’t it be ripped one way of the other?

[Ziggy]

On the felt blocks, last batch was quite softer then the set before.
That said … I was not happy.
But, it gave me an interesting progression.

In the rough stages, soft wood.
At around A35 to leather with boron, the older harder felt.
Then last very light passes on leather and various compounds, the softer felt blocks.

It makes a difference.
The softer felt, you can feel how smooth the slide is, as well as any hangups. Any bit of burr seems to catch on that softer felt with a very light touch. I guess kinds like catching a burr with a q-tip.
If the light last pass is not perfect, a light 1 or 2 across the leather seems to take care of it, so till it glides … rinse and repeat.

Now, to find the harder felt again as I’m just about out ….

[Author]

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