Unicorn buffing

[David Silverson]

I've been buffing all my plane blades and chisels for some time now and am very impressed. My one concern is removing the wire edge that can be felt after buffing also on the buffing wheel. I wondered if in fact it introduced a micro back bevel to the blade. I've switched to removing it on a fine stone just in case.

[Winston Chang]

It's possible that what's on the back is not a burr, but some buffing compound. When I started using a buffer, I thought I had the same thing, but when I looked at it very closely, I found that it was actually buffing compound that had accumulated on the back of the blade. This is what the back of the blade looks like after buffing only the bevel side. The white/yellow stuff is buffing compound.

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A very light and quick (like less than 1 second) pass of the back of the blade on the corner of the buffing wheel cleans it up just fine for me, without introducing any appreciable back bevel.

Now, if the last stone you use before buffing leaves a relatively large burr, it is possible that the buffer won't remove it very cleanly. That's not a big problem for most chisels, but it can be for plane blades. For plane blades, I try to cleanly remove (or at least greatly reduce) the burr by working both sides of the blade on a finer stone (6000 grit) before going to the buffer.

[David Silverson]

I always remove the burr raised by the stones on the stones. I'm pretty sure it is a burr raised by the buffing. I don't think it will reduce the effect of the buffing by removing the final burr back on the stones, do you?

[Winston Chang]

I don't think that taking it to the stone again would be problematic, although that could also raise a burr, so you'd want to be careful with it. You can try it and see how it works for you.

From my experience and from the experiences that I've heard of, the buffing wheel definitely does not create a burr, as long as you use a soft-ish cotton buffing wheel. I have many microscope photos of the fronts and backs of blades and have never seen the buffing wheel create a burr. (That said, if the burr is large to start with, I have seen instances where the burr was not removed cleanly.) So if you are indeed getting a burr, I think that we must be doing something different from each other.

I have heard that a hard buffing wheel (like felt) can create burr, so if you're using a hard wheel, you may want to try using a softer one.

[David Silverson]

No I'm using a soft wheel. I'm away for a bit but will check again on my return.

[Derek Cohen]

David

I generally stroke the back of the blade on a "strop" made of green compound on hardwood. I have used the edge of the soft wheel. Psychologically, the strop feels safer, but I am sure that Winston is correct.

Incidentally, I caught a short video by Rob Cosman, who was advertising selling a blade set up for a high cutting angle. This had a 20 degree back bevel. He talked about how he sharpened this blade: Rob stated that the back bevel remain untouched and that only the primary/secondary bevel be honed. Then the wire on the blade be removed by stropping on the palm. This made me think of the removal of a wire on a unicorn profile.

Regards from Perth

Derek

[Jim Matthews]

It's possible that what's on the back is not a burr, but some buffing compound.

Beat me to it.

I tough the back of the blade to the (untreated) side of the cotton wheel.

[William Fretwell]

The obsession with obtaining the sharpest edge possible afflicts us all. The mark of a true hand tool woodworker! We all end up with a similar set up of stones and hones. When we get really good at it we can then blame the steel!

[Jim Matthews]

We all end up with a similar set up of stones and hones. When we get really good at it we can then blame the steel!

The surprise in this approach is how well even middling quality chisels behave with the very tip of the bevel blunted. The results are surprisingly good, and cheap to acquire.

Being fast doesn't hurt my feelings, either.

[Derek Cohen]

The surprise in this approach is how well even middling quality chisels behave with the very tip of the bevel blunted. The results are surprisingly good, and cheap to acquire.

Being fast doesn't hurt my feelings, either.

Jim, exactly so ..... when David first posted this method, the purpose was to improve the edge longevity of chisels with lower quality steel.

Regards from Perth

Derek

[Eric Rathhaus]

For me the speed with which I can bring a sharp edge back to a plane iron is the most significant benefit, although my speed freehand sharpening might be called tortoise like.