I also have a supply of scalpel blades (used to work in an OR), and they are razor sharp when new, but quickly lose their edge on plastic, and wood. I’ve sharpened them on a whetstone but they’re never they same as new.
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See if you can find a black Arkansas whetstone. That was the best thing to use back when disposable blades weren’t so inexpensive. Brownells.com at least used to sell them.
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I thought the same thing about oil sharpening going in. It turns out there is an ongoing debate in the culinary world on the merits of oil stones versus water stones. In my case, water sharpening makes the most sense because the necessary materials are sitting in my sanding box, it is less messy, and screwing up a hobby knife blade does not matter.
Water sharpening also worked for some of my kitchen knives. If I were going to sharpen one of my big, expensive, diving knives, oil honing would probably be the way to go.
This is definitely not for everyone. Matt is right. New blades of decent quality are plenty sharp and cheap. I am finding sharpening useful for keeping a modest edge on a blade, effectively indefinitely, and honing more expensive, specialty blades.
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Some sharpening stones want oil,
others use water,
bone dry causes friction,
oil or water holds on to the fine
particles loosened from the
stone and creates a grinding paste.
With oil/water makes for easier work
but sharpening can be done without
though with a lower quality result.
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Time for the heretic in me to reveal a secret:
I own CHEAP cooking knives, bought cheap at a large
grocery store or a DIY store which sells cheap tools
and gadgets. Stainless steel (not carbon steel, just
plain old bog standard stainless), I do require the blade
to have a V-shape, continuous taper from the back to
the edge. This gives me a smaller angle at the cut
compared to single thickness blades which only have
a 60 degree point ground into them.
I sharpen those cheap knives until they can slice 2.5 mm
(1/10th inch) thick slices from tomatoes in one single cut.
I sharpen them on the bottom edges of porcelain, just grab
a teacup, saucer or dinner plate from the sink, turn it over
and start grinding. My kitchen cabinets are full of “stones”,
I could use (cooking) oil but water is always handy by the sink.
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I don’t engage in any activity with a lower quality result in mind.
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my question would be- in which direction to go to put a sharp edge, away from you or towards you and of course in a slicing motion i assume.
Joe
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You really need to watch a video or three on knife sharpening before attempting this.
In the end, the biggest benefit was to my kitchen knives.
Still have not found or made a chisel I like. Still experimenting with that one.
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Some stones are designed or intended for oil, others for water. Diamond stones are fine with either or none. A lot depends on what one is cutting, and the desired result. If cutting flesh that will then be sutured or otherwise healed, the smoother the cut, the more rapid the healing. For denser material, a very sharp, smooth blade may make the cut difficult, whereas something more “saw-llke” will cut more efficiently.
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how do i know which stone i have? one i have has a v in it on both sides to sharpen fishing hooks, the other is a stone that came with a bowie like hunting knife. the sheath had a snap enclosure to hold it. both look the same material, i use them dry to sharpen the exacto blades but never seem to get an edge sharp enough even though it looks sharp.
Joe
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Unless the grit coarseness is marked on the stone, it can be hard to detrmine, though the finer grained the surface looks, the finer the grit. With very fine stones, the surface texture can be invisible to the naked eye. The one with the grooves for fish hooks is probably a medium-fine grit, as fish hooks need a fine point.
For sharpening hobby blades, I use a fine hard ceramic plate called a “streak plate” by geologists, gemologists, and rock hounds. Alternatively, I have a very fine diamond stone, 2000 grit IIRC. For scalpel blades, I use a “Surgical Black Arkansas stone”—search on that name and you will find them. Ceramic stones are usually used dry, as are diamond stones, though either can be used with water or oil. Because I’m not doing surgery, I use oil on the black Arkansas stone. The purpose of the lubricant is to lift and carry away the fine metal particles produced by sharpening. Note also that some stones are compatible with oil, others with water, and some with both. When sold these are labeled as such.
Finally, sharpened blades can be stropped. This is done with a strip of oil or wax and very fine abrasive impregnated leather. This is what you sometimes see barbers using when they shave a client with a straight razor.
Blade sharpening is both a science and an art, and takes practice to be done well.
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thank you martin. i think mine are of medium fine grit. should i use water or oil with these or dry.
i will look for the diamond stone too
Joe
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A good but somewhat crude measure: How does the grit compare to a diamond nail file? If you can file your nails with it, “medium fine” is probably close. In this case, I’d try water—you don’t need oil contaminating your model surface.
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