Natural Japanese waterstones update
I was going to revive a previous thread on Natural Japanese Waterstones, but it didn’t let me, so I’m starting this new thread. If you haven’t read that previous thread you might like to wade your way through it as it contains a lot of useful background discussion, along with the usual quota of banta and fooling around to be expected on this forum.
I wanted to revive this thread for two reasons; 1st reason is that the following question came up in another thread on Japanese knives.
Quote:
Originally Posted by
Bushmiller
The natural waterstone versus the man-made waterstone. In fact I raised the question as to whether anybody does really part with thousands of dollars for them. Clearly there are varying qualities in both natural and man-made stones. Are the natural stones so very good (or just for some purposes) ?
Second reason is that it is now five years since this topic was originally tugged about here and there may be new contributors and further experience and thoughts from the original contributors to add to our collective wisdom about Tennen Toishi (Natural Sharpening Stone).
As we have both woodworking tool and kitchen knife sharpeners coming at this topic with different perspectives, I might kick the thread off by attempting to outline in what way the needs of these two types of uses differ, in the hope of avoiding confusion between the two uses.
As succinctly as I can put it, with the risk of much over simplification:
- Woodworkers (usually) need straight sharp edges that stay sharp. Woodworking blades are pushed (or hit) into the wood and need to be sharpened to optimise for that.
- Kitchen knife users (mostly) need toothy sharp edges that stay sharp. J-kitchen knives are at their optimum when used with a slicing action, although some knives, or parts of knives, are adapted for chopping.
For woodworking
On the same quality of steel and in the hands of an experienced user, the sharpest longest lasting edges come off the finest and hardest stones. The two additional qualities that are claimed for natural stones for this purpose are the variation in grit size and the hardness of the finishing stone. The advantage of variation in grit size was well covered in the discussion in the previous thread. The hardness of the finishing stone has been shown in lab tests to 'consolidate' the metal in the edge to produce a longer lasting sharp edge.
Opinions vary on whether the cost, extra time and effort to achieve this is worth it with woodworking tools.
For knives
Given the same quality of steel, the sharpest longest lasting toothy edges come off softer, not quite so high grit, stones (as those preferred by woodworkers and razor users). Variation in grit size in a natural stone contributes to the toothy edge. 'Tooth' refers to micro-serrations that can only be seen under high magnification. The misty finish off such stones also helps reduce 'stiction' during use in the kitchen.
Again, there are various opinions on whether the cost, extra time and effort to achieve this is worth it on a kitchen knife.
Aesthetics
In addition to any claims about improving the performance of a blade with natural waterstones, there is general agreement that the naturals bring out the variation between the soft iron and hard steel in a blade, and also the laminations in Damascus cladding. This is purely an aesthetic consideration which may, or may not, be appreciated by the user.
Cost
On the cost of natural waterstones; like gold, there is a limited supply of them and their price reflects that. Likewise, larger or rarer stones also command much higher prices. Their price doesn't correspond closely with their utility. But, like gold and some wines that are purchased as a commodity investment, some of those expensive stones will never be put into daily use. Yes, there are toishi collectors!
Buying natural waterstones in the past has been a tricky undertaking, frequently ending in disappointment. Has this changed?
Anyone have any insights (new or revised) that they would like to share on their naturals?
Neil