bevels?

[bladerunner105]

hi, i was wondering if you really need to make a bevel on a knife before sharpening it. for example could i just put my blade blank not sharpened or beveled on the lanskey
and start on it? will it profile a bevel? also i would like to know the advantages of a full flat grind vs something like a scandi grind. thanks

 

[chiral.grolim]

"Sharpening" is the process of grinding a bevel on a knife.

If starting with a bevel-less blank, you may need to remove a LOT of metal via grinding to achieve a sharpened edge. Depending on the thickness of the edge before grinding, your Lansky may not have a sufficiently low grit to take off material quickly enough to satisfy your needs. You are wasting your time.


The difference between a full-flat grind and a "scandi" or saber-grind is blade thickness and bevel angle. For two blades of the same width, spine thickness, and edge-thickness, the angle behind the edge-bevel will be greater on the saber-grind, resulting in a thicker blade everywhere but the spine and edge. One could make a saber-grind blade than is thinner/lighter than an FFG blade by using thinner stock-material or using a hollow (concave) grind rather than flat or convex. Most utility razor-blades have a flat saber grind.

A thicker blade has greater lateral stiffness and strength as well as weight, worse cutting efficiency - it is preferred where such strength is required, e.g. if the blade stock is very thin or the blade will be subjected to significant forces/stress.
A thinner blade is lighter, more flexible, more efficient cutter - it is preferred where strength and impact-resistance are not as important for using the knife, e.g. most knife tasks.

 

[TravisH]

I don't believe the Lansky system will be very effecient. Too much material to be removed.

If you don't have a grinder, here's Aaron's excellent vid on building and using an inexpensive bevel jig ...
[video=youtube;r9iNDRwwBQQ]https://www.youtube.com/watch?v=r9iNDRwwBQQ[/video]

 

[GatorFlash1]

hi, i was wondering if you really need to make a bevel on a knife before sharpening it. for example could i just put my blade blank not sharpened or beveled on the lanskey
and start on it? will it profile a bevel? also i would like to know the advantages of a full flat grind vs something like a scandi grind. thanks

Here is an explanation YouTube video about knives and cutting edges from the Spyderco Wizard himself. There are four videos in the series and I would recommend viewing them all. The sharpening logic applies to all types of sharpeners.

https://www.youtube.com/watch?v=5LBDnJv5B58

I rarely sharpen the back bevel because I am careful to only sharpen the primary micro bevel enough to get it sharp. There is no reason to sharpen away more steel from the edge than is necessary.