sharpening stone-carving tools

[hpatenaude]

If anyone has some advice for sharpening stone carving tools (by hand using coarse and fine grit oilstones), please let me know. Most information online is for sharpening wood chisels and/or seems to rely heavily on grinders and other things, I'm simply interested in simple hand honing and am wondering if I should be making a circular motion or pulling in or out, so forth.

[Sysiphus]

hello. i am a chef (as well as a stone sculptor) and i sharpen all my own knives. with knives it's most effective to run the blade the length of the stone in the direction you would cut, usually at a 20 degree angle. i would assume that this would be the same for chisels. the only time i do circles for my knives is if i'm trying to grind a specific spot down due to a knick or burr in the edge. for my chisels i use a dremmel with a grinder attachment. hope this helps.

[Mordachai]

Hey

Check out Bladeforums.com
There is a multitude of people over there and all they think about is knives and using them and maintaining them.

You will see that there are many ways to sharpen your tools.

|M|

[Bill Harsey]

I'm pretty late to this conversation but might be able to offer some usable stuff here.
Yes Bladeforums has a lot of information but I usually need advil after reading there for any length of time.

The short version of my history is that I've been making and designing knives for 25 years now using performance oriented tool steels.
Being able to sharpen these edged tools by hand is important so the user can do it in the field.

The purpose of my response here is to both start an answer on how to sharpen the stone tools and encourage anyone to sharpen their edged tools because with some practise, it isn't that hard to do.

The first thing I remind myself of when sharpening is that this is a steel removal process, this means don't be afraid to push hard while sharpening.

For stone tools made of steel and NOT carbide, I would use a combination stone made by Norton, one side "Fine India" which is aluminum oxide and the other a medium grit called Crystolon that is man made silicon carbide. The longer the stone, the more work we get done per stroke. I think my bench stones are about 11 inches long. Of course we can make the shorter stones work too.
These man made stones are very durable and I would sharpen tools on them as if i was trying to take a shaving off the surface of the stone by pushing the tool down hard like it was making a cut.
Do not take the tool off the stone on the return pull, then push hard again. Look and see what is happening on the tool, adjust your angle if needed then keep going.

Mount the stone on a bench top that allows you to push down hard on the tool. Too high of a bench top and your elbows will hurt trying to put pressure on the tool as you abrade it on the stone.
The cheapest/fast benchtop mount for a stone is a decorative rubber dinner setting mat that you find at the Marts. Just put the mat down and put the stone on top and it won't slip. Get the thinnest one possible so the stone doesn't "wiggle" too much.
This also works good on the tailgates of pickup trucks for field work.

Use the full length of the stone to abrade on and shift places often, don't "dig a rut". Wear your stone surface evenly especially with a narrow tool.

Draw yourself a picture of the dull tool edge in cross section and visualize what you have to remove to make it sharp again. If there is interest, I will do this and scan it in for upload here.

It helps to wear some magnifiers while you work so you can see exactly what part of the edge your working on.
The reason some kind of oil is used on the stone is to keep the abraded particles of steel removed from the tool from sticking to the surface of the stone. When the stones surface gets "full" of metal, it no longer cuts.
I use kerosene or WD-40 spray oil from the can. You bad kids need to put out the cigars when your spraying the WD-40.

Sharpening is a matter of steel removal and this takes some applied force, don't be afraid to use some muscle, the job will get done faster.

For out in the field I carry and use DMT diamond sharpeners. I just returned from a week in Oregon's Steens Mountain Wilderness and all I carried was the DMT diamond Dia-Fold sharpeners for touch up. The reason I bring up the diamond stones is that I use them all the time in the shop here to touch up cutting tools like lathe bits, milling cutters and drill bits. Diamond doesn't care how hard steel or carbide is, it sharpens carbide cutters too.

If you folks have further questions about sharpening, let's keep this going because sharpening is very important to the artist. This short text is just a start, not the end.

[Bill Harsey]

OK, here are a few highlights of edges I've designed and produced using some of the hand skills I've started to mention:

I've made prototype edged instruments for eye surgery, designed to be self guided and work out of the surgeons range of vision on the backside of the patients eye.
I've produced microtomes for a plastic and reconstructive surgeon. These depth guided edged tools are for doing single layer skin removal for the grafting related to wound and burn healing.
The scalpel that did all the re-opening work for a double tendon reconection in my right hand was produced by me the night before surgery, (that hand had just finished 7 days work for critical deadline with the tendons not connected) I also stayed awake to make sure the doc used my knife like he said he would.

There are many more layers to what I do but you can find out about that some other day.

If anyone wants, I'll lay out every technique I've got for sharpening tools.

Edited to add: The greatest wrong is to waste anyones time and if you have a question I can answer, please ask. If you have something I can learn from, that's good news too.
Getting the work done is always my first goal.