Spyderco Sharpmaker 204MF Blade Sharpening System

The Spyderco Sharpmaker 204MF consists of a plastic base unit which is slotted to take the sharpening stones. A pair of medium grit and fine grit stones are supplied togther with a pair of brass safety rods. The three sharpening angles permitted are 30, 40 and 12 degrees. The stones may also be positioned side by side in the underside of the base with the flat surfaces uppermost, for use as a conventional whet-stone. The slots in the base also allow the stones to inserted in a point-to-point or flat-surface-to-flat-surface configuration. Initial sharpening is done using point-to-point which is more aggressive, followed by flat-surface-to-flat-surface. The major benefit of this system is its simplicity. Provided the knife is held vertically during sharpening, the correct angle will be achieved.

Point-To-Point Stone Configuration Flat-Surface-To-Flat-Surface Stone Configuration

Medium Grit Sharpmaker Stones
The medium-grit, grey colour, alumina-ceramic sharpmaker stones are manufactured in USA, in a process which combines a bonding agent with alumina particles. Alumina particeles are essentially synthetic saphires measuring 15 - 20 microns. The Spyderco sharpening stones are shaped and kiln-fired at 1649 degrees centigrade.

Mohs Scale of mineral hardness: This characterises the scratch resistance of various materials by comparing the ability of a harder material to scratch a softer material. For example, talc measures 1, pure gold measures 3, hardened steel measures 7 , diamond measures 10. Alumina Ceramic sharpening stones manufactured by Spyderco, measure 9 on this scale.

Maintaining a 40 degree working edge is a step by step process:

• Start with the stones inserted in the 40 degree base slots
• Insert stones in a point-to-point configuration, that is with two angles or points positioned opposite.
• Ensure the two brass safety rods are in place, and with the unit on a flat, level surface, use one hand to hold the base steady
• Hold the knife by the handle, in the other hand with the cutting edge vertical, the blade tip pointing away
• Starting from the top of the stone, run the blade down the stone, from the heel to the tip of the blade
• Apply a medium pressure, making sure the entire edge makes contact with the stone from the heel to the tip of the blade, with the tip of the blade ending up at the black plastic base
• Repeat the procedure for the opposite side of the edge on the opposite stone

After 5 to 10 strokes on each side ot the edge, re-position the stones in the 40 degree slot, with flat-surface-to-flat-surface configuration. Repeat the above procedure for 5 to 10 strokes on each side of the edge or until sharpened sufficiently. To produce a finer edge, repeat the above procedure using the white, Spyderco Fine Grit Sharpmaker Stones.

This method has the advantage of lubricant-free sharpening, although after prolonged use, stones will need cleaning to remove microscopic steel particles adhering to the stone. The sharpening effectiveness is gradually reduced as the stones become loaded with steel. They are easily cleaned by washing in fresh water and scrubbing with powdered abrasive and a scouring pad to remove steel residue from the open cell structure.

Spyderco Diamond Sharpmaker Rods

Spyderco diamond rods are made of hollow steel with a triangular cross section. The coating of industrial diamonds is applied to the steel with nickel-plating. The exposed tips of the diamonds forms a highly abrasive surface. It is more effective to use a gentle stroke as the cutting depth is limited by the size of the diamond tip. The diamond surface can be damaged if too much pressure is applied in the sharpening process. Therefore it is better to sharpen with several strokes at medium pressure and this also prolongs the life of the diamond rods.

The Sharpmaker kit also includes an instruction booklet and DVD. These include detailed instructions for sharpening scissors, chisels, serrated edges and more.