This review consists of :
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This review consists of : |
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Ad copy from Tools From Japan :
These special waterstones are purpose designed for shaping and sharpening High Speed Steel and also to cut faster in harder, tougher steels than any other stone available. To accomplish this they are composed of abrasive and nothing more. There is no binder as is present in most all other waterstones, which means that these stones do break down a little more quickly than hard ceramic stones. In exchange for this apparent flaw, they cut significantly faster than any other commercially available waterstone on the market. Depending on the steel being sharpened, between 30-200% faster, which alleviates the dishing concern to such an extent that in most situations, it will not be noticeable. Simply put, they do their work before they have a chance to get out of flat. Made by compressing abrasive under high pressure and heat as a type of sintering, these unique stones might rightly be called a true 'ceramic' stone, and are unlike any other stone commonly known. While they are designed for very hard, tenacious and tough steels, they also cut more simple and softer steels at a rate that is difficult to describe. If you are used to waterstones that 'cut quickly', the Select II is on an entirely new plane of fast. These stones do require some soaking, especially the lower grit stones, but perform best 'just damp' and after some slurry is generated which occurs very quickly. They are also virtually immune to clogging due to the abrasive breaking free of the stone so easily. Any possible clogging is removed as soon as it occurs. Occasionally the term 'amazing' might be used for waterstones, but is only really appropriate with these. They truly are amazing.
This is a pretty open stone, note the images on the right showing at 50X magnification the difference between :
both at 1000 grit.
It comes dry as it normal for waterstones and takes approximately 15 minutes to get a full soak and stop bubbling.
As a first trial experiment, some very inexpensive kitchen knives were sharpened by the SPS-II :
and the King :
This is about a 2:1 difference, however these are different knives so not too much confidence can be given in that ratio. However a few things are obvious even from the initial comparison :
The immediate concern is the faster cutting ability simply due to a rougher finish. A quick check of this was on an :
The image on the right shows the finish without the usual techniques to refine the edge :
A more extensive comparison vs the King was done to zero a grind on a SRM 710 :
Note the images on the right showing the before and after of the regrind. This took :
to produce a true zero 4 dps bevel.
The difference in cutting speed can be seen on the rag used to wipe the blades clean. Note :
It may be possible to make the SPS-II a little harder / tighter bond, however it has a very nice balance of cutting ability and release of abrasive. The King wears so fast that even one comparison / regrind such as on the SRM 710 will take 1/32" off of the stone.
This is also making sure to wear the ends of the stone as well as the middle however the stone is so soft that unless the blade is very wide and straight it cuts hollows in the stone immediately. This is with knives, with small chisels and similar it almost gouges immediately.
As another similar comparison both knives were used to zero another knife, the Fallkniven PXL :
The result to produce a 6.5 dps bevel :
After about 10k passes the stone still had no visible hollow but was flattened on granite :
The passes were very short (about 4" ) as the piece of granite was very short and thus on a full size lapping plate it would be lapped with 50-100 passes. These are also very light, just the weight of the stone.
Comments can be emailed to Please Use the Forum or by posting to the following thread :
and/or the YouTube Playlist for Abrasives/Sharpening.
Most of the pictures in the above are in the PhotoBucket
album.
| Last updated : | |
| Originally written: | 09/09/2013 |