Tip #15
Honing (continued)
Click here for a printer friendly version of Tip

Water Stones

There are two types of water stones: aluminum oxide and “rare earth compound”. They come in four different grits ranging from coarse to ultra-fine that are classi-fied like sandpaper: 800, coarse; 1000, medium; 1200, fine; and 6000, ultra-fine.

The softer water stones are usually used by moving the cutting edge into the stone. To avoid gouging a soft water stone, the cutting edges of tools narrower than 1/2", and/or curved tools must be moved away from the stone as if you were trying to smooth it.

Aluminum Oxide-The 800, 1000, and 1200 grit water stones are aluminum oxide. These reddish-brown stones are relatively soft and likely to wear and dish even when used properly. When worn they are easily flattened. They are porous and must be soaked in water overnight when new. They are fast cutting, easy to use general purpose intermediate stones that, when taken care of, will last a lifetime.

Rare Earth Compound-The 6000-grit water stone is made of a "rare earth compound". Exactly which earth compound is considered a trade secret by the makers of this white, very high quality polishing stone. It is porous and must be soaked in water overnight when new. It is slow cutting, but relatively easy to use and will leave a mirror-like surface on the bevel of the tool and the sharpest cutting edge possible. It will, when taken care of, fast a lifetime and be able to be passed on to future generations.

The Water-As the name implies, water stones are used with (and in) water. In fact they are best kept and stored submerged in wa-ter. The water keeps the stone clean and cutting well. Out of water these stones will only glaze over and almost immediately stop cutting. The water used with these stones is nothing more than distilled water with a drop or two of chlorine bleach added to prevent the growth of bacteria.

Maintenance-The water stone will dish after use even with the best of care. Either after using these stones, or before each use, they should be flattened. Just how soft these stones are will be very evident the first time you flatten one.

Figure 24-2. To flatten a water stone, use a generous amount of water and rub the stone over wet/dry silicone carbide sandpaper.

To flatten a water stone, lay a sheet of 220-grit wet/dry, silicon carbide sandpaper or a dry-waller's sanding screen, on a flat, waterproof surface. A piece of laminate covered sink cut-out works well.

Apply a generous amount of water to the abrasive sheet. Place the stone on the sheet and hold it with one hand while rubbing the stone over the abrasive sheet with the other (Figure 24-2). Work the stone until all the gouges are gone. You will find that this process takes only a few minutes.

Figure24-3. After the water stone is flat, bevel end the edges as shown.

The last step in this flattening process is to bevel the edges to prevent them from chipping (Figure 24-3).

Continue to Rubber Bonded Abrasives
Back to Oil Stones