JesusFreak
Shohin
Does anyone have any advice on what tool I should use to sharpen my bonsai tools? I’ve seen wet stone and diamond sharpeners. Try not to spend an arm and a leg.
Sharpening my tools
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leatherback
The Treedeemer
I use both, but find the diamond-on-steel sharpening "pens" best for quick on the spot maintenance. With a regular wetston I have a very hard time to sharpen anything but scissors and knifes. Maybe I will get a sandstone stick. hm
BonsaiDTLA
Shohin
I need a sharpener for my grafting knife, would love to hear what others suggest!
Mike Corazzi
Masterpiece
Fine diamond stone. Just do the flats on the scissors. 
Well, do the edges too but it's a bit more delicate.
Well, do the edges too but it's a bit more delicate.
RJG2
Omono
Not that I need to, but I've been curious of how people sharpen their concave cutters.
Do you bother? Something like this?
Do you bother? Something like this?
Gabler
Masterpiece
Sharpening regular knives is tricky enough to do correctly. Sharpening irregularly-shaped blades is even harder. Make them opposed blades, and it gets especially difficult. By far, the hardest part is keeping the edge angle aligned. Keeping a steady hand and also steady pressure takes practice. Here's a few tricks I find helpful:
Use a strop. Seriously. Never underestimate the power of a simple strip of leather. If you use it often enough, you may never need to touch a stone.
If you have to use a stone, move the stone, not the blade. Put the blade in a vice to keep it completely immobile, and use two hands to hold the stone steady for a consistent edge angle. Be sure to use good sharpening stones that offer a secure grip for fine control. Diamond-covered sticks look like they'd be effective for tight spaces, but the degree of control is so poor, you may find yourself ruining the blade.
Prop open tools with opposing blades to prevent the stone from blunting the opposing blade while the clamped blade gets sharpened.
Remove material from the inside of the inside blade and the outside of the outside blade. Afterward, use a strop on both the inside and outside of both blades. This will help maintain the alignment of the tool so the blades meet in the middle and cut cleanly.
Stop and take a break if your arm gets tired. Tired muscles have poor fine motor control.
Use a strop. Seriously. Never underestimate the power of a simple strip of leather. If you use it often enough, you may never need to touch a stone.
If you have to use a stone, move the stone, not the blade. Put the blade in a vice to keep it completely immobile, and use two hands to hold the stone steady for a consistent edge angle. Be sure to use good sharpening stones that offer a secure grip for fine control. Diamond-covered sticks look like they'd be effective for tight spaces, but the degree of control is so poor, you may find yourself ruining the blade.
Prop open tools with opposing blades to prevent the stone from blunting the opposing blade while the clamped blade gets sharpened.
Remove material from the inside of the inside blade and the outside of the outside blade. Afterward, use a strop on both the inside and outside of both blades. This will help maintain the alignment of the tool so the blades meet in the middle and cut cleanly.
Stop and take a break if your arm gets tired. Tired muscles have poor fine motor control.
Gabler
Masterpiece
Fine diamond stone. Just do the flats on the scissors.
Well, do the edges too but it's a bit more delicate.
That's all well and good for cheaper tools, but finely-aligned scissors lose that alignment if you start removing material from the flats. Remove steel from the outside angled side of the edge, and only use a strop on the inside to remove the bur and maintain that perfect alignment.
Gabler
Masterpiece
One other thing: It's usually impossible to get a good edge on stainless steel. The one exception I've found is the patented stuff that Victorinox uses. As cheap as it is, it's also surprisingly good at holding an edge.
Gabler
Masterpiece
Grafting knives are exceptionally easy to sharpen, since they only have a bevel on one side of the blade. Buy a pair of water stones, one medium and one extra fine. Use them only on the beveled side. Use a strop on both sides of the blade to take off the bur and improve the longevity of the edge.
Gabler
Masterpiece
Oh. And one other trick I forgot to mention. Get a second strop and work an extra fine polishing compound into the flesh side of the leather. It'll combine the benefits of a strop and an extra-super-duper-fine polishing stone.
Brian Van Fleet
Pretty Fly for a Bonsai Guy
I wrote an article on it a couple years ago; we have a club member who practices this on a very high level, and he taught me the process, but the skill itself must take years to master.
nebaribonsai.wordpress.com
Sharpening knives and scissors
A friend who has been sharpening tools for a very long time; to near obsession (which is a very good quality), offered to give me a lesson and some pointers on the art of sharpening knives and scis…
nebaribonsai.wordpress.com
I've been sharpening bonsai tools for years, how you sharpen them depends on the wear. For example, scissors wear on the inside as the opposing edge shears across it. This is because scissors have to torque for the cutting edges to meet. This is also why you can't use right hand scissors with your left hand. At the hinge the blades are flat and parallel, eventually the blades wear more than the hinges, that the cutting no longer make contact. Grinding the flat with hinge intact dpeeds up this process, and creanmates absolutely destroy scissors. The only options at late wear stage is to grind the bevel back to a flat area, or seperate the reigns and flatten the blades.
Scissors blades ors sometimes straight or curved, which may cause issues if you grind the inside flat area with intact hinge. Also, good quality scissors will be hollow ground behind the cutting edge to reduce friction. And some scissors are laminated with a hard steel on the cutting face. All factors to considered.
So lots to consider regarding sharpening
Concave cutters and knob cutters need a round stone to sharpen properly. I use a suitably sized socket wrench wrapped in carbarundemn paper. You can stick the socket in a battery powered drill set on slow to make it easier.
Try not to sharpen the outside bevel on concave, knob and branch cutters as the angle between the inner and outer bevel is very important to the finished cut.
Will post up some pics later
Scissors blades ors sometimes straight or curved, which may cause issues if you grind the inside flat area with intact hinge. Also, good quality scissors will be hollow ground behind the cutting edge to reduce friction. And some scissors are laminated with a hard steel on the cutting face. All factors to considered.
So lots to consider regarding sharpening
Concave cutters and knob cutters need a round stone to sharpen properly. I use a suitably sized socket wrench wrapped in carbarundemn paper. You can stick the socket in a battery powered drill set on slow to make it easier.
Try not to sharpen the outside bevel on concave, knob and branch cutters as the angle between the inner and outer bevel is very important to the finished cut.
Will post up some pics later
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Wires_Guy_wires
Imperial Masterpiece
One of the most underestimated tools in the sharpening business.
I use one for my straight razor (which I barely ever use, but I own one because it's cool) and I've been able to keep it sharp for a decade without ever touching a stone.
erich_raudebaugh
Shohin
I have one of those but they are pricey I think. I use Japanese wet stones with various shapes, for pre-polishing, I also have dozens of grinding stones for my Foredom, so sharpening any shape is pretty fast actually. Just takes a few minutes when you get the hang of it, well maybe 15 minutes or so. I also carve wood so I have dozens of chisels and gouges, I used to be a woodworker for a living so you learn to sharpen tools quickly. A leather strop loaded with medium-high polishing compound from a stick will get a mirror edge on tools but it isn't necessary for concave cutters. 8000 grit water stones will produce a mirror polish too, as will stainless polishing compound on a buffing wheel. Touching the edge up with a ceramic or fine diamond round tool will keep it sharp, even silicon carbide sandpaper will work if you're careful to maintain a single angle and have a variety of grits to work up to 800+ before stropping if desired. Silicon carbide or alumina wet/dry sandpaper on a sheet of glass will work if you don't have diamond or water stones. 3M makes very fine sanding films that are backed with a thin flexible plastic and ideal for this. It's easy to make a strop with a scrap of leather, suede side up glued to a strip of wood with contact adhesive, then sand it a bit to roughen it up and flatten it, with a random orbital sander or even a board with sandpaper (150 grit).
Mike Corazzi
Masterpiece
That may be true. Cheapies work for me as I have a minimal collection. I stone and strop my knives and get a scary sharp edge.
Tools? Nope.
JonW
Shohin
What do you guys do for concave cutters? I know a few people gave suggestions, but anything simple and affordable? I've seen people use fine grit sandpaper on a sponge to conform to the shape of the blade, which I think works in a pinch but the pressure wouldn't be consistent and would still offset the blades over time I think.
To sharpen concave and knob cutters you need something round and hard. It should be just a tidge smaller than the arc of the cutters.
Cut a 10 mm wide strip of carborundum paper just long enough to overlap. Tap one end down with something.
The tool should have a narrow bevel which you sharpen. It should be flat so that you can register the sharpening die.
You put the round sharpening tool you just made level on the flat (see Top photo) and rotate it by twisting your wrist, if the paper bunches up you're twisting the wrong direction. Do half a dozen or so twists, reverse the paper and go the other direction. Make sure that the round thing you have is just slightly smaller than the arc of the cutter , otherwise you will wear down the shoulders and not sharpen the centre part. If your cutters do not have a flat bevel than you cannot sharpen this way as there is nothing to register the correct angle.
Cut a 10 mm wide strip of carborundum paper just long enough to overlap. Tap one end down with something.
The tool should have a narrow bevel which you sharpen. It should be flat so that you can register the sharpening die.
You put the round sharpening tool you just made level on the flat (see Top photo) and rotate it by twisting your wrist, if the paper bunches up you're twisting the wrong direction. Do half a dozen or so twists, reverse the paper and go the other direction. Make sure that the round thing you have is just slightly smaller than the arc of the cutter , otherwise you will wear down the shoulders and not sharpen the centre part. If your cutters do not have a flat bevel than you cannot sharpen this way as there is nothing to register the correct angle.
JonW
Shohin
A sanding drum might also work if you can find a fine enough grit. Thus far, I've tended to gently sharpen the edge that does not touch the other blade with something round, then just try to remove any burs on the other side (that does make contact with the opposing blade). I like the idea of using a strop more often and avoiding sharpening - I wonder if I can figure out a way to do the same. Maybe making a stropping drum bit rather than a sanding drum bit!
