How do I get started with the InversionEdge™ Sharpening System?
Please see our detailed instructions and video HERE.
What motion is needed?
While the exact motion of the stone isn't important, it is best to avoid pressing down while dragging the stone back toward the edge. This doesn't hurt the knife, but can shave your stone away faster than necessary. Press while pushing the stone away from you, and release while dragging back, even if the motion is mostly lengthwise.
What knives does the InversionEdge sharpening system work on?
All Japanese and Western blade knives, both single-sided chisel edges and regular two-sided edges. The system is not designed for serated knives, however the stones can be used to sharpen serated/bread knives.
For knives such as the birds beak, just tilt the stone sideways enough so one edge of the stone only contacts the blade. The angles are the same.
How long does it take to sharpen?
It all depends on the condition of your blade. The easiest is to work for two minutes then test the edge. If it feels sharp, stop, otherwise you’re just removing more precious blade material for no benefit. We recommend cutting some food, particularly tomato, as a good real-world test. Do not use finger feel unless experienced! If edge isn’t sharp, continue the process and test every few minutes. If the fine stone really isn’t working, switch to the coarse stone to create new secondary bevels, repeating sharpening process until edge feels sharp, then switch back to the fine stone to finish off the tiny primary bevel.
Do I need both the fine and coarse stone?
It really depends on the quality and sharpness of your knife blades. The coarse stone is perfect for repairing and reshaping worn knives of any type, and the fine stone is ideal for maintaining any blade already in perfect condition. Essentially, once your knives are back to good condition, the fine stone keeps them that way.
I'm struggling to get sharp edges on my paring knives and narrow blade knives.
Narrow blades are usually thicker at the cutting edge (otherwise too weak), and have far wider angle bevels than broad blades. It doesn't look like it to the untrained eye, but for those reasons they actually take more work per inch than most other knives! It's likely not enough metal has been removed to create a new edge, and the old worn edge is still present.
Wouldn't the angles change depending on the height of the knife blade?
The variance is so minimal that it doesn't don't matter in the context of this system. The variations from the curve of the blade, wear of the stone, motion, etc, might amount to 2 degrees. That won't be detected by the knife user, or the food, and the final result is still far more accurate than any human manually using stones, so not worth worrying about.
How does the InversionEdge™ system adapt to the curved edge of a knife blade?
All that's required is a slight adjustment and variation in angle of the stone, to follow the curve of the blade. It will feel very natural. The 1 or 2 degree of variation makes no difference to the performance of the edge.
How is the InversionEdge™ system better than a honing steel?
A honing steel does more harm than good, unless angle control is near perfect. Humans can't achieve that, which usually results in rounding the edge to the point that a lot of metal needs to be removed, to restore bevels.
A fine water stone with perfect angle control is far better for maintenance with minimal metal removal and no round edges.
If you have previously used a honing steel, it may take longer than expected to achieve a sharp edge using the InversionEdge™ System, due to how rounded and damaged the blade is. A fair amount of metal may need to be removed to restore bevels and achieve a sharp edge. Use the Coarse stone to remove the metal, and once you've achieved a 'coarse sharp' edge, switch to the Fine stone to finish off your blade.
Does the InversionEdge™ sharpening system work with other types of whetstones?
The system is designed to fit Naniwa combination stones, which are 2cm thick. The clips are tight though can be manipulated a little if need be, so will fit many stones.
What are the angles of the InversionEdge™ sharpening system, and what if I want other angles?
The ‘lower’ end of the tray (visibly less angled) has a platform at 23°, and this generates 16° and 26° edges with the Love Handle on low and high orientations, respectively. The ‘higher’ end of the tray has a platform at 28° (visibly more angled) generates 21° and 31° edges. The Naniwa stone is mounted in the Love Handle with the 3000 grit on the low side, and 8000 grit on the high side (because you want to rough out the big secondary bevel with the coarse stone, and finish the final primary cutting bevel with the wider of the two angles). If you want other angles, you can raise the stone to greater angles by placing spacers of any kind (such as cutting boards or similar) between the tray and Love Handle.
Will the sharpening stones wear out over time?
Naniwa stones are the hardest Japanese water stones available and extremely durable. It will take a lot of use to wear these stones down, though like all stones, if they become too dipped anywhere, they can be easily flattened again. The love handle can be widened or narrowed (with a bit of force) to fit.
The handle is scratching my tray!
This system is designed to be a working tool, however if you want to protect your tray to avoid scratching, you can place some paper/fabric/tape underneath the handle.
I'm struggling to get my whole knife blade above the tray edge.
Long and very curved blades will sometimes need the handle off the side of a bench to fit (it will hit the benchtop). Japanese pro sharpeners on water stones rarely attempt to sharpen the whole length of a blade in one swipe, but work on smaller sections. If the blade is too long to make a whole sweep, work in sections - the Japanese are the real masters! Both methods work, but for larger, curved knives, you may be beneficial to work in smaller sections.
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