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Stephen Sebed
04-02-2003, 11:26 PM
I need to find a good stone to use to sharpen knives, chisels, scissors, and everything else that needs to be kept sharp. I have never seen any wett stones in a store until the other day when I noticed a stone which was made of silicon carbide (I think). where do you find sharpening stones? I would like something that stays pretty flat and I don't care if I have to use a dressing. Also any tips on using the stone successfully would help also.

Thanks,
Stephen

Tom Scott
04-03-2003, 9:35 AM
Enough material has been written about sharpening to fill a library , and many debates have taken place about the merits of different sharpening systems. For a good general purpose stone, I don't think you could go wrong with a diamond stone. They last a long time, stay flat, and you can get them with dual grits (ex. course on one side, fine or extra fine on the other).
Of course, there are lots of other options...oil stones, water stones, ceramic stones. You could probably get a better edge with these, but they may require more skill, money, and upkeep.

Oh yeah, there is also the "scary sharp" method, in which you only use varying grits of sandpaper.

Tim
04-03-2003, 11:03 AM
Hi Stephen,

Various stones should be available in any woodworking equipment outlet. Also available online at places like woodcraft.com, rockler.com, leevalley.com and many others. The current issue of Popular Woodworking has a good article on sharpening and the author specifically uses Norton waterstones (but discusses others as well). If you can pick up that issue, it would probably help to answer a lot of your initial questions.

Stephen Sebed
04-03-2003, 5:22 PM
Will the silicon carbide stone that I mentioned work well? If so, do I need to use any oil or water with it?

Thanks again

Marc Hills
04-07-2003, 12:14 PM
Hi Stephen:

I think you are looking at what I’m making do with, which is a very inexpensive double-sided “coarse/fine” synthetic oilstone. Yes, you do need to lubricate it with oil. If you haven't noticed any alternatives in stores, then you’re probably like me and have limited access to a Woodworker's Warehouse or similar hobbyist store. This cheapie combination stone can actually take you reasonably far, especially in comparison to not sharpening at all, which I sense a lot of beginners do.

I use baby oil (basically mineral oil) or sometimes even WD40 on the fine side of the stone to sharpen my chisels and plane irons. I don't bother much with the coarse side unless I'm working on a seriously dull edge or removing a nick.

I then use polishing compound and finish off with car finish scratch/swirl remover (both available at any automotive parts store) on some scrap leather to strop the edge. I use the side of the leather with a nap.

You can get a reasonably sharp edge this way (sharp enough to shave hairs off my forearm) and it gets your feet wet inexpensively while you agonize (as do I) over what "real" sharpening system to go with (Japanese waterstone, Norton waterstone, Arkansas oilstone, diamond hones, scary-sharp, etc., etc.)

I’m VERY aware of the beginner pitfalls for sharpening, so if you think it would help, I can talk you through exactly how I sharpen chisels and plane irons. The two most important concepts for me were learning about removing the burr and establishing a micro bevel.

Hope this helps.

Stephen Sebed
04-07-2003, 4:03 PM
would you please explain how to remove the bur and more importantly how to establish a microbevel?

Thanks

Marc Hills
04-07-2003, 11:24 PM
Feel free to step in and correct me here anybody.

Stephen:

Add some oil to your oilstone and take the tool, say a chisel. Set the bevel side of the chisel against the stone and slowly raise the handle until the bevel is in full contact with the stone. I'm right handed so I lightly grasp the handle with my right hand with my index finder extending down along the shank. With my left hand I rest three fingers on the tool near where it contacts the stone and let my pinky lightly drag against the stone surface. I use my left pinky to "feel" the angle and maintain it throughout the sharpening process. This sounds more complicated than it is, the idea is to position the tool so as you move it in a roughly oval motion, the bevel surface maintains a constant angle and stays in full contact with the stone.

As you do this, you are removing a minute amount of metal, and this metal has to go someplace. Where it goes is along the edge of the tool in the form of the burr.

After several seconds of sharpening the bevel side, you will raise a burr along the opposite side the tool's edge -- you can actually feel it by lightly running your finger along the edge from the flat side of the chisel. Flip the tool over and set it down so the back side (non-bevel side) is flat against the stone and again work the tool back and forth, up and down in a oval motion. This removes the burr. I'm not sure if this really happens, but I feel like if I do this too long, I'll raise another, smaller burr, this time on the bevel side. Sometimes, I alternate back and forth between the bevel and non-bevel side, working down to progressively keener edge without any burr.

Next, you want to establish a microbevel.

You know what the bevel is: depending on the thickness of the tool and the angle of the primary bevel, you have maybe 3/8" of surface that constitutes the "depth" of the primary bevel.

What you want is a second, much smaller, shallower bevel, again on the same side as the primary bevel, that is at a slightly steeper angle. If your chisel is beveled at say 30 degrees, then the micro bevel is something like 35 degrees. No I don't measure and I don't use a honing guide. I just "guesstimate."

Once I'm satisfied with the primary bevel and I'm confident I've removed the burr, I again place the tool against the stone, bevel side down. I slowly raise the handle of the chisel until the bevel surface is in full contact with the stone -- just like before -- but then I raise the handle just a bit beyond that, another 5 degrees or so. I don't get hung up about precision. For all I know, I'm adding just a couple of extra degrees, or maybe I'm adding ten. The point is you want to hone a new bevel somewhat steeper than the primary bevel. This second bevel will not have much depth to it, I'm guessing 1/128th of an inch, hence the name micro-bevel.

You will get a tiny burr sharpening your micro-bevel, so you have to repeat the process of working the flat side of the tool. Just a few strokes will do it this time around.

The microbevel is desirable for two reasons that I'm aware of. One, you are concentrating on a very narrow area and you can bring it to a keen edge very rapidly. Try to sharpen the edge along the entire depth of the primary bevel and you have to remove a lot more metal. You are working the tool longer and that introduces more opportunity to unintentionally vary the angle at which you hold the tool, ruining the sharpening process.

Two, when the edge of a micro-beveled tool gets dull, you can touch it up very quickly, again because you only have to remove a very little bit of metal to restore the edge along the shallow micro-bevel, as opposed to the much deeper primary bevel.

Then I move on to stropping with the polishing compound and car finish scratch/swirl remover that I mentioned in my previous post.

This all sounds so much more complicated than it really is. I confess I don't "look" for the burr or even the microbevel. The trick is to be conscious of them and take that into account as you sharpen your tools.

I hope this helps.

Marc

John Wadsworth
04-08-2003, 10:36 AM
Stephen,

If you'd like an amplification of Marc's excellent description, with pictures, there's one on the Museum of Woodworking Tools website--featuring the teacher I started with, Maurice Fraser:


http://www.antiquetools.com/sharp/index.html


Look around at the rest of the site, while you're at it--it's a great place.