waterstone grit contamination?

[Stanley Covington]

Using a single tub can be a problem, in my experience, when trying to produce a super-sharp and super-beautiful edge. For this reason, I don't use a tub at all. However, for practical sharpening, I don' think you should have to worry too much.

Contamination from dirty water can be avoided by using clean water from a bottle to wet stones instead of scooping it from a tub of muddy water. I responded to another thread on Nagura recently and gave the basic formula for sharpening water.

The water spritzer you mentioned is good enough to wet dried stones, but not adequate for washing stones. You need enough running water to flush the grit off. A few handfuls of clean water may suffice. A hose or tap would be better. I don't like spray bottles anyway. My sharpening station is very crowded, and a spray bottle gets mist everywhere including dry blades and tools resting nearby. A plastic wash bottle (the kind with the bent tube) works best, IMO.

A very common culprit for grit contamination is transfer of mud from one stone to the next by the blade. It is easy to leave a bit of mud on a blade's corner. This can get embedded into the next stone in the progression, and mixed with the mud causing ongoing problems. Clean the blade thoroughly before moving onto the next stone. Do a final wipe on a clean, white paper towel that will easily show mud.

If you suspect contamination has occurred, wash the stone in clean water, work the face with a nagura, and wash it again to remove mud and any embedded grit. Sometimes I use a brush to scrub my stones. Be sure to touch up the bevels at the stone's edges, and to clean the dried mud off the sides.

Dust and airborne grit can quickly contaminate your stones, and is often very hard. This is especially a problem on dusty jobsites, near roads (even paved, apparently clean roads are inherently dusty, and passing cars kick up dust), or in desert areas like Southern California or Nevada. Keep your stones covered when not in use. I wrap mine in newspaper. Try to keep dust down when sharpening. Splashing water on the ground or concrete floor around your workplace helps.

Stan