Posted by: woodbeecarver   in Knives

In an old Western border town jail two inmates are trying to loosen a bar in the window for a planned escape.  Skinny weights a mere 170 pounds and Tiny weight 230 pounds.  Finally, they loosened the middle bar enough that they wiggle it out and Skinny squeezes himself through the remaining bars.  Tiny tries to squeeze through but is too fat and gets stuck half way out and half way in. Thus, the old saying, “Thin is in but Fat is where it is at,” came into play.

Bevels on a carving knife blade can affect the slicing ability in that a thin bevel cuts a little easier than a fat bevel even though both cutting edges are sharp.  The difference is the thickness of the bevel on the side of the blade. The cutting edge is made up of little teeth that separate wood fibers as the cutting edge is sliced through the wood. The bevel’s purpose is to spread out the fibers on either side of the cut with the thinner the bevel the deeper the cut.  A fat bevel will only go so deep until its fatness will slow depth of the cut.  A thin bevel will seem to be sharper than a fat bevel but it is the thickness of the bevel as it goes up the side of the blade that affects the efficiency of the sharpness of the cutting edge.  The blade slices through the wood in a one – two punch ~ cutting edge separated the wood fibers and the thickness of the bevel spreads the fibers to allow the blade pass through the wood.  By the same token, the thickness of the bevel strengthens the cutting edge.  This means that carving in basswood, a thin bevel will work very well while a thicker bevel will be better for a harder wood like walnut, cherry or butternut as far a protection for the strength of the cutting edge.  Although either type blade will work in most wood.

The illustration below compares three different bevel thickness as a point of reference for further discussion.

Illustration “A” shows a bevel that would be for general purpose cutting of a pocket knife blade where the cutting edge needs the greatest protection.  The 30- degrees represents the angle of approach this kind of bevel would allow the blade to begin its cutting action.  Illustration “B” shows a bevel that goes about half way up the side of the blade with a 20-degree angle of approach of the blade to begin its cutting action. Illustration “C” shows a bevel that goes from cutting edge up  the side of the blade to the back edge with a 13 degree approach the blade to begin its cutting action.  Most of Helvie Knives are shaped with a bevel like “B” which allows the cutting edge to enter the wood fairly quick and its roll out is fairly quick.  Carving blades that have a flat grind with bevel going from cutting edge up side of blade to the back edge like “C” causes the blade to enter the wood at a lower anger and makes a longer run in its roll out phase.  Blade “C “also is preferred because it seems to feel a little “sharper” and “quicker” to slice because of its “thin” bevel, especially for detail carving.  Blade “B” with its quicker “roll out” effect works very well for rough out shaping.    Some “B” blades may be made of thinner steel and even with the fat bevel its initial thinness gives it a feel of a “C” type blade.  It all boils down to the personal choice of each carver and some carver may adjust a “B” blade into a “C” blade by thinning the side of the blade to lower the fatness of the bevel.

Tuning up a Helvie blade with a “B” blade bevel can be maintained by stropping often by laying the blade flat on the leather strop and stropping several times on both sides of the blade following the curvature of the cutting edge.  After a long time of carving use and stropping often the cutting edge may become rounded over.  This will become evident to the carver needing to strop the blade more often to keep it functioning normally.  At this point, it may be necessary the “tune up” the cutting edge by using the Super Fine Diamond hone by laying the blade flat on the hone. Then raise the back edge up very slightly so that the cutting edge is touching the hone and then following the curvature of the cutting edge sharpen the cutting  edge back and forth several times on one side, then repeat several times on the other and when a very fine burr edge appears the length of the cutting edge it is time to strop the blade to remove the burr edge and polish the newly formed cutting teeth of the cutting edge.  Make test cuts across the end grain of a basswood stick to test sharpness and then strop a few more times for good measure.

Bee Sharp and Never Dull ~ Sharpening like Carving is the more you do the better you do.  In the doing find what works best and never be afraid to experiment the path of trial and error where learning takes place.

This entry was posted on Wednesday, January 19th, 2022 at 9:41 am and is filed under Knives. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

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