Folding Skinner #1



Cutting contest started out very informally. It was just a bunch of knife makers who wanted to compare the quality of their knives to that of their fellow knife makers.As the contest evolved and became more formal size limitations were imposed on the knives.Sizes were standardized at 15 inches maximum over all length, 10 inches maximum blade length and 2 inches maximum blade width. At that time the goal was to build the best Camp Utility Knife. I learned more about what makes a knife work properly in ten years of competing in cuttung contest than I learned in the previous foryt years of knife making. A cutting tool that is designed to perform one function is very specialized. Extreme examples of this ate the razor and the ax. A camp utility knife is designed to perform many functions well. A knife that is designed to chop heavy sapplings for a shelter may not be the best knife to shave tinder for a fire or pick a splinter from your finger. This means compromise. Everyone has their own ideas about stuff like edge geometry, what type of grind is best, blade profile,handle shape and many other features. In this article I will discribe the knife design I arrived at after building 15 prototyps in 5 years of on going test and observation. For me that was what it took to design such a high performance knife. I'm sure not everyone will agree with me on every point. To these folks I say contact me let's hear what you have to say. I'm always ready to learn more.


THE BLADE is hand forged from 5160 high carbon steel. It's a steel that holds up well under the stress of hard chopping. It takes a scary sharp edge and will hold it a long time and is easy to resharpen with the right tools if heat theated properly. The back of the blade is straight and in line with the handle, to give maximum power for penetration when stabbing. The edge is curved from the choil to the tip. this makes a more pointed tip than a blade with a straight edge and a sudden upward curve at the tip. A blade with a curved edge slices better. When chopping a curved edge penetrates better. When the edge first contacts the object to be cut the power is concentrated in a smaller area and there is a degree of sliceing. The belly is deepest at the sweet spot. (see bottom knife in photo. above) The blade has a flat grind for deeper peniteation and less overall weight.The spine of the blade is thickest at the sweet spot which is 4 inches from the point of the 10 inch blade.The blade tapers from this spot both directions (see top knife in photo. above) toward the point and towatd the back of the tang. The blade is flat ground from the spine to .025 inches at the cutting edge. Then a compound radius is put on the edge to form a cutting edge that will chop well with minimal damage and slice well also.  


THE FULL TANG is skeletonized to serve two purposes. One purpose is to remove weight from the back of the knife. This moves the sweet spot forward, toward the point and also lightens the knife for carrying. The other purpose is to accommodate a tuning fork.


THE TUNING FORK has two purposes. One is to absorb shock when chopping. This causes less stress to the joints amd muscles of a person doing vigorus or prolonged chopping.  The second purpose of the tuning fork is as an indicator. If the object to be chopped is struck by the sweet spot on the blade no vibration of the tuning fork will be felt and deepest penetration will be achieved. If the blade contacts the object to be chopped forward  of or behind the sweet spot the tuning fork will vibrate. This vibration can be felt by the hand of the person doing the chopping, thus allowing this person to correct the next blow.


THE HANDLE consist of teak wood scales mounted on a skeletonized full tang. Teak is used because it's a tough ,oily wood that stands up to abuse well. It doesn;t crack or warp as readily as most natural handle materials. After the scales are epoxied and pinned to the tang they are shapped with a rotary rasp mounted to a high speed hand held dye grinder. The tool grooves formed by  the rorary rasp are left in the handle.This makes for a textured handle that resist slipping in the hand. The shape of the handle of a knife is very important to how well a knife performs. On this knife the groove for the index finger serves two purposes.the first purpose is so that the knife is less likely to slip forward in the hand. The other purpose of the finger grove is it helps form a palm swell. This gives a stronger grip when performing task that require twisting and and sawing motions.The butt of the handle is turn down in a birds head configuration. This forms a stop for the little fingerand that helps keep the knife from slipping forward when chopping. Another thing that helps keep the knife from slipping forward is the drop in the handle. Since this is an all purpose knife the drop in the handle isn't to great, allowing for more comfort while performing task other than chopping.


THE THONG HOLES in this knife both serve diffrent purposes. The one in the butt of the handle is more for the protection of other people who might be near when you are using the knife. Such as in a cutting compition. The second hole is in the top of the recasso. This puts it forward of the handle. It's for a stronger grip on the knife. The way this works is the thumb is inserted through the loop that is formed when a thong is passed through the hole in the recasso and the two ends are tied together. The thong is passed over the back of the handand then around the palm. If this is done correctly the thong ends up under the pawl between the hand and the knife handle,comming out from under the hand at the front of the handle. (see photo. above)If the loop is the right size the thong will be snug around the hand not letting the hand slip toward the back of the handle while the hand remands closed on the handle. If the grip on the knife handle is released the thong will no longer be snug and the hand can slip free.To me this is much safer than having a large razor sharp knife attached to you by a loop around the wrist.

HEAT TREATING - After the knife is forged it's heated again untill ite cherry read then it's let cool untill it has turned completely dark. This is done three times. This aligns the grain and makes the grain fine as possable. Next the knife is heated in an electrec oven to 1450 degrees and the heat is slowly reduced over a period of  hours to anneal the steel. After the knife has cooled to room temp. it is ground on a 1x72 belt gringer and hand worked to the finished shape. Next the tuning fork is milled into the tang. The knife is then submerged in molted salt that has been heated to 1550 degrees. Aftrer being submerged for 90 seconds it's removed and immediately submerger molten low temp salt that has been heated to 385 degrees. After 10 min. in the low temp. salt it's removed and and submerged in room temp. water to desolve the salt. It's them washed with a high presure hose to remove any remaining salt. It's then checked for any warpage that may have occured during the heating in the salt. If any warpage is present it is removed at this time. The knife is hand sanded to a 400 grit finish . The tuning fork is covered with a heat resistant paste and the tang is annealed with an acetyline torch. The spine of the blade is then heated to a bright blue this soften this part of the bladed to the hardness of a leaf spring. The knife is then heated in an electric oven at 385 degrees for 3 hours. This is a tempreing prosess that slightly softens and toughens the cutting edge. It also relieves any stress created in the steel by heating different  parts to different tempretures.

GRINDING AND SHAPPING - After the knife is annealed the center of the blade is ground flat on both sides to .250 inches. Then the flat sides of the knife are tappered starting 5 inches back from the point to.100 inches thick at the back of the tang. Next it's tapered starting 3 inches back from the point to .130 inches at the point. The corners formed by the tapering are now rounded. A hardened steel pattern is then used to drill the four holes and to scribe the profile on the knife. Next the profile is cut. Then the blade is flat ground forming a taper from the existing thickness of the spine to 025 inches at the cutting edge. The final shapping of the flat grind and the sholders at the tang is done by hand. Next the rounded edge geometry of the cutting edge is done with a slack belt on a belt grinder.The edge is formed by two compound radiuses joining at the edge at a 30 degree angle. Before hardening in high temp. salt the whole knife is hand finished to 400 grit.

WEIGHT and BALANCE - Because of the flat grind of the blade, the taper from the center of the blade to the back of the tang and the skeletonizing of the tang this knife weighs less than one pound.This lack of weight means a lot if you're carrying this knife all day along with a lot of other gear. Although this is not a heavy knife to carry, it chops as well as a heavier knife or or a small ax with less effort. This weight forward ballance is accomplished because the thickest (and heaviest) part of the spine is aproximately in the center of the length of the blade.The widest part of the blade is also in the approximate center of the blade. Putting the sweet spot closer to the tip of the blade is an atvantage in two ways. First it delivers more power at the sweet spot for deeper penitration on more resistant materials. It also delilivers more velocity for less resistance on a slashing cut.


SHEATH - I like to carry a sheath knife on my strong side. It always seemed awkward to me to have to lift so high when drawing a knife with a long blade. This is compounded when the knife binds in the sheath on the way out. To get around this problem I designed the EZOut Sheath. All you have to do to get the knife out of the sheath is unsnap the leather strap at the top of the sheath, tilt the handle of the knife forward and lift the knife about four inches. This is accomplished by having the top two thirds of the sheath open the front. This works well because of the way the knife is secured in the sheath. When the knife is installed in the sheath, a half circle cut out at the bottom of the recasso of the knife fits around a leather lug of the same shape and size inside the sheath at the top and back. The horizontal strap at the top of the sheath holds the knife to the rear locking the half circle cut out in the lug. The strap is secured with a snap. 

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Enter supporting content here      Jery Lairson Sr. 605 McAtee Lane  Ringold, Oklahoma  74754   Phone (580) 876-3426