Reluctant burr

[Randy Long]

I'm new here. Been experimenting with a CBN wheel for carving tools. The wheel is turning away from me as I sharpen but I seem to get burrs that are long and won't break off. Could this have something to do with the direction of the grind? This does not happen when the wheel is turning towards me. When the wheel is turning away from me, the burr just seem to hang on and drag out even when I go to finer grit wheels. Could be the blade is soft steel? Or the wheel is just pulling the burr outwards and not breaking it. The burrs can get thick and heavy and difficult to remove. Thanks!

[Randy Long]

In simpler terms, are the burrs different when the wheel is running towards you, as opposed to running away from you?

[RichColvin]

Randy,

The late Dr. Vadim Kraichuk wrote an excellent book about deburring knives and made a shortened version of it free for distribution.  Whilst it is about knives, I believe many of the principles will apply to what you are finding.

To get to the book, this link will get you there: https://www.sharpeninghandbook.info/Documents/Knife_Deburring_book.pdf.

You can get the full-length version from Amazon.

Kind regards,
Rich

[Randy Long]

Thank you Rich! Now I know I wasn't imagining things. I seem to get different burrs depending on the grind. Now to produce that elusive wire edge...

[John Hancock Sr]

I wasn't imagining things

The burr is created by the plastic deformation of the steel. The amount of deformation (size of the burr) depends on a number of factors. The plasticity of the metal, (cheaper knives are more ductile), the sharpness of the grit, a freshly trued stone wheel will produce a smaller burr, and sharpening away from the edge will produce a larger burr since the metal is being dragged towards the edge. How hard you press the tool into the wheel will also impact the burr.

You burr is a combination of softer steel, pressure on the tool, and the direction of the sharpening. If the tools have been sharpened on a regular bench grinder they they may have list their temper due to heat. Otherwise make sure you sharpen with the wheel running towards the tool, make sue the final passes are on a sharp wheel, and use very light pressure on the final passes.