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Edge Pro Apex Sharpening System 
Reprint from "Sharpener Review Magazine"

Table of Contents
 - Introduction
 - Impressions 
 - Initial Honing 
 - Touchups 
 - Abrasive specifics 
 - Removing the burr
 - Test for Sharpness
 - Drawbacks
 - Summary

The Edge Pro sharpening systems were developed by Ben Dale through an extensive professional sharpening experience. The basic system, the Apex model, comes with two stones, medium and fine, (180 and 220 grit), lapping compound, water bottle, cleaning cloth, instruction manual, and carrying case. Stone upgrades are available in coarse (100), extra fine (320) and ultra fine (600). There are also polishing tapes, very fine abrasive sheets which attach to blanks. Two ceramic sharpening rods are also offered in 600 and 800 grit models for touch ups. Ez-lap diamond plates are available in the correct size to enable mounting to the blanks, and various grit of sandpaper can be used as polish tapes. Pictures can be seen on the (taken from the Edge Pro website) . 

The sharpener allows for smooth variation of angle from 10 to 35 degrees per side. Several degree increments are marked out clearly (10,15,18,21,24), but you are not fixed at using these set angles. The aluminum oxide waterstones are one inch wide and six inches long. They are mounted securely on the guide rod with use of clamps between plastic molded grips which also serve as protection from the stone slipping off the knife and damaging the edge. As the blanks are not permanently fixed to the guide rod they can easily be used for field freehand honing if desired. The hones can also be reversed to slow down hollowing. 

The instruction manual which comes with the system is well written and is even informative if you are not using the Apex system. In addition to specific info on how to use the Edge Pro, there is also additional commentary on blade angles, long and short term edge maintained, and hone lapping. Also presented is the end goal in terms of both method as well as what is happening to the actual edge of the knife. Sections are included for both basic and advanced users. A videotape is also available which shows the sharpener in action. 

UPDATE : when I bought the Apex several years ago I purchased all the hones, an 800 grit ceramic rod and the polishing tapes, of which at that time were being offered in 2000 and 4000 grit. Recently the grit selection of the polishing tapes was changed to a single 3000 grit version. 

The system is well constructed and comes together solid with no difficulties under a minute, no loose parts, rattle or wobble. It completely removes the subjective judgment of obtaining a consistent vertical edge angle between the blade and the hone. Unlike systems like the Lansky which use a clamp, the Edge Pro has the blade simply rest on a platform. The lack of a clamp permits the blade to be rotated as the hone is drawn, the goal being to keep the hone perpendicular to the edge. This is an easy task as judging a ninety degree or "square" angle isn't difficult and it allows a constant angle to be ground from choil to tip and permits the sharpening of blades with significant curvature. If the blade isn't moved on the rest, the Apex will simply put a more acute bevel on the blade towards the tip. This isn't actually a bad choice as it leaves the tip very acute which can be a positive attribute for fine cutting. 

Initial Honing 
Using the Apex over a variety of blades, it becomes obvious that the coarse hone is essential. Most production knives come with poorly ground edges, the angles on can vary along the edge and from side to side and frequently there are hollows in the grind. The first sharpening job therefore can require the significant removal of metal even if the blade is not dull simply because the edge has to be evened out. This is best done with the fastest cutting abrasive which means the most coarse. Assuming the current edge angle on the blade is going to be maintained, the coarse hone on the Apex will produce an edge edge out of even a sloppy and hollowed bevel in just a few minutes. The guide arm allows a lot of pressure to be used with little effort. One the edge is uniform, the sharpening process continues to the desired grit of finish. Matching the initial angle on the blade with the correct setting on the Apex simply requires the use of a marker on the edge and some trial and error on the angle settings. When the angle on the Edge Pro matches, the abrasive scratches will completely remove the marker outline from the edge. 

If the angle on the blade is going to be changed significantly, which in general is a good idea as most production knives have far too steep an angle, the coarse hone again does a solid job. However the time will now be significantly longer. How much time depends on the length of the blade, the nature of the steel and how much of an angle change is required. For example fifteen minutes of honing would make a major angle change on a small folder, even if it had a hard and wear resistant steel blade. Life can be made easier here if blade aesthetics can be abandoned. Use of a very large bench stone and some lapping compound will allow much faster reshaping of an edge, extreme care in angle consistency isn't required here as this isn't actually sharpening, just shaping. The goal is to hog off enough metal to get a rough shape. The Edge Pro will then very quickly refine the shape. Very coarse sandpaper can also be used instead of the bench stones. 

The ceramic rods can be used for general maintenance, used the same as you would a smooth steel. The rods are abrasive so they will clean up the edge on a microscopic level, removing bent and broken steel, refreshing the edge leaving it much stronger than if just a smooth steel had been used. However the ceramic rods will leave the edge with their grit finish and thus can change the nature of the cutting performance by altering the size of the micro-teeth on the edge. A smooth steel leaves the edge tooth profile almost unchanged, with just a light polish from the slight smearing out effect. The sharpness produced by the smooth steel however is temporary as the edge will relax over time back to the deformed state. The sharpness of the ceramic rod is more stable. Since the smooth steel does not remove any metal, it doesn't decrease the lifespan of the knife, however fine ceramic rods remove material to a depth of about a few microns, it would take hundreds of such sharpenings to remove one millimeter of blade steel which is a little more than one thirty second of an inch. 

If these touch ups are done freehand, unless you have considerable skill and can match the bevel produced by the Edge Pro, a secondary bevel will be created. At first this will not be visible, but in time a narrow grind will appear at the very edge. Each touch up will start to take slightly longer than the last as the additional bevel widens and eventually the Edge Pro will have to be used to reset the edge, removing this additional bevel. This process can in fact be avoided completely and the Edge Pro used to do the touch ups. If this is the case, the system should probably be left setup, and the stones soaking to insure that it is ready to be used. In general though, this is overkill unless the demands for sharpness are very high. The ceramic rod does a very nice job at freehand touch ups, and a simple mount can be easily made to set it at a known angle. Cheap v-rod setups are also available at flea markets which make the task even easier [ref] . 

Abrasive specifics 
The aluminum oxide waterstones will load up if used dry, especially the fine ones. They need to be fully saturated, as more water is applied it will remain on the surface of the stone. While the coarse ones soak up water very quickly, the rate of water absorption decreases as the stones get finer and thus the really fine ones work best if left soaked, and can easily be stored in a a simple plastic container. A small squirt bottle should be used to flush the stones periodically when in use. 

As the abrasive breaks down with use, over time the stones will lose their flatness and develop a hollow, they then need to be ground back to even. The more coarse hones will hollow out the fastest. To restore them you simply grind them back to flat on a piece of plate glass using sandpaper or a lapping compound for as the abrasive medium. If the hollow is really deep you can cut it back initially on a concrete block. The lapping is finished when the stone shows grind lines across the entire surface. As a quick check, run a marker down the middle and then see if the line is completely ground off with a few passes. After the lapping the hones will absorb water very fast and cut more efficently, the finish will also be slightly more coarse but this will stabilize very quickly. 

In regards to grit specifics, the coarse hone leaves an edge well suited to aggressive slicing of ropes and other hard to cut materials, and the ultra fine hone produces a very fine polish for general push cutting. The tapes will produce an optimal mirror finish and they can be also be cleaned after use to extend their lifetime. 

Removing the burr (or wire edge) 
One of the biggest problems with sharpening is the removal of the burr, a weakened strip of metal which and tends to flop from one side of the edge to the other during the honing, Wayne Goddard addressed this issue in his article in sharpening in Knives 2002, complete with pictures under high magnification of an actual edge burr. A burr can be seen by eye in the worst cases, but in all instances can be easily detected with a simple shaving test, or thumb pad rake across the edge, taking care of course as always with a sharp edge. If a burr is present the edge will feel much more aggressive on one side than the other. The removal of this burr is the final step in sharpening and is achieved on the Apex by adjusting the angle up a few degrees and giving the blade one pass on the hone, alternating sides. Usually only one stroke is required, no more than a couple should be used. The easiest way to develop skill in removing burrs is to practice on the worst case possible which is soft steels, especially cheap stainless kitchen knives as these easily develop very large burrs. When these can be removed without difficulty, quality steels will sharpen with ease. 

Test for Sharpness 
In the simplest perspective, a sharp blade will cut well. Cutting ability in general depends on a lot of other factors, but for any particular blade the greater the sharpness the higher the cutting ability. A coarse finish should be checked on a hard material like poly rope. The knife should cut aggressively with no slippage and progress evenly though the cord, sinking in an even manner under a light load. If the blade is left with a high polish it should be able to push cut straight through newsprint, again with a smooth cut, no snags or tears. If a more quantitative approach is required, the push cutting ability can be measured by the how much force is required to cut light thread, and the slicing aggression tested by how much edge length is require to cut some hemp using a specific amount of force. These simple tests only require the use of a regular bathroom scale and a simple spring scale. 

Aside from the raw cutting ability, the overall quality of the edge is also judged by how well it stays sharp. An edge which is cleanly formed and has no burr present should be able to retain the full razor edge through a decent amount of work. How much so depends on the nature of the steel in addition to the quality of the sharpening, so it can be of benefit to have as a reference a blade that is professionally sharpened. The best way to benchmark the performance of the Apex is to have a test blade so sharpened by the maker, Ben Dale. A free test sharpening is offered by Mr Dale (see the Edge Pro website for details). This both allows the examination of the abilities of the system before purchase, as well as providing a solid reference for what can be optimally achieved once the sharpener is in hand. 

Drawbacks - extreme curvatures and serrations 
The only drawback of the Apex is that it cannot handle extreme curvatures such as found on a Hawkbill. Essentially the curvature cannot be of such an extent that the blade changes shape significant over the width of the hone, about an inch. For the blade that are so radically shaped, optimal sharpeners are rod based systems of which the Spyderco Sharpmaker is the current flagship model. Serrations also cannot be honed except to give the back a light lapping. This will maintain the edge for awhile, cut eventually they will have to be fully sharpened, this is again one of the strengths of rod sharpeners such as the Sharpmaker. 

The Edge Pro Apex offers a wide array of abrasive grits and sharpening angles, making it much more flexible in that regard than most clamp and v-rod systems. The cutting speed is also high with the very abrasive nature of the coarse hone and the ability to apply heavy pressure. However it cannot do touch ups or handle serrations as well as a quality v-rod system such as the Spyderco Sharpmaker. Customer service is first class, Mr. Dale was always responsive to sharpening queries through email. 

Edge Pro "Apex" Portable Knife Sharpener
Price- $129.95    Add to cart