Sharpening for a school shop

[Dave Cav]

OK, hot on the heels of my last discussion about 300-400 grit stones, I have another sharpening question for the collective. As some of you may know, I'm a high school shop teacher. For the last few years I have been sharpening my chisels and irons on a belt sander and then honing on a felt wheel. It's quick, but leaves a lot to be desired in terms of edge quality. I also can't turn the students loose because they would grind everything blue and down to a nub pretty quickly. I'll show you our lathe chisels some time...

What I'm looking for are stone(s) that are not expensive, durable, not fussy and will give a "good enough" edge, and something I can show the students how to use as well. We'll probably use an Eclipse style honing guide. These are 16 year old kids, remember. I'm starting to think Spyderco, but I'm open to suggestion, and to tell the truth, a pair of Spyderco stones is a little more than what I want to spend, especially considering I'll probably buy several sets. My budget is pretty limited.

Thanks again.

[Chris Griggs]

I'd be inclined to get something like a coarse/fine India stone and a hard ark. That's about as bombproof as your going to get and they won't really wear out. I used to be high school teacher but I'm not as tough as an oil stone, so the students wore me out in only 3 years.

Maybe this set http://www.toolsforworkingwood.com/s...Wide_Oilstones (I think thats less expensive than a pair of Spydercos?)

[David Weaver]

You can still use the belt sander to grind and then you can use any of the following:
* any ceramic 1000-2000 grit stone and a bare leather strop
* medium and fine india (this might be the best choice, the two together are cheaper than most individual decent stones, and available in 8x3)
* a hard arkansas

I think maybe the medium and fine india are the best choices. You won't have to keep them watered, they'll be coarse enough to hone the edge that's ground on a belt, etc.

[David Weaver]

twice today now that I was a couple of minutes late!

[Chris Griggs]

twice today now that I was a couple of minutes late!

Sorry Dave! Looks like you've rubbed off on me a bit too much....

[Jim Koepke]

For regular use, the Arkansas and India stone combo might be your best bet.

You might consider demonstrating the use of abrasive paper sharpening as in the "scary sharp" method and also show and explain water stones. This would inform the students who will continue in the craft that there is more than one way to hone a blade. Could be a quick 15 minute to a half hour seminar.

jtk

[Greg Wease]

At our school we use diamond plates for coarse and medium grits and a 7000 water stone (sorry I don't know the source) for final honing. Diamond plates are the only medium that survives the hundreds of students sharpening each semester. We flatten the 7000 grit stones daily. I also introduce scary sharp as a short-term option that becomes too expensive in the long run due to the cost of abrasives. We recommend that beginning students stick to new chisels (Narex has worked well for us) but we also have a few Tormeks to enable hollow grinds on older, damaged blades. We have some Eclipse type guides but most students are comfortable with freehand sharpening on hollow-ground edges.

[Jim Foster]

The King waterstones are not too expensive, and they are easy to clean and re-flatten. 800, 1200 and 6000, or maybe skip the 800. Another reason, waterstones cut fast, it may keep the kids more interested since they can see progress quickly.

[Dave Cav]

Thanks again for all the great input. Remember, these are VERY inexperienced 15-16 year old high school kids I'm working with. Due to storage, mess and added complications (soaking, sequence, flattening), water stones are out. Diamond plates are a good idea, but the cost for decent ones would probably be a deal breaker. I think the combination Norton India stones are a great idea, and the "fine" side would get things sharp enough for what we need to do in addition to teaching the basics of sharpening. After all, I grew up using a generic (and badly dished) synthetic oilstone my dad had, and we did ok back then; a combination India stone would be an improvement over that.

[Don Jarvie]

The sharpening segment at North Bennett street uses a norton fine India and oil. You learn to flatten the back, the hollow grind then hone the bevel. You only use the one stone.

Its a pretty easy system to learn and there were plenty of students in my class that had no clue. We learned how to sharpen for 2 days, all day so it sunk in.

[Adam Neat]

Dave you might do well to fire off an e-mail to Norton and DMT and explain your situiation. They might be able to provide some advice and perhaps a "student" discount on some products. They may also be interested in some feedback in what would probably be a pretty good testing ground for sharpening stones

[Kevin Groenke]

Hey Dave,

I'm in a college shop with ~400 regular users, we try to keep chisels sharp but it can be a full time job. I tried diamond stones, waterstones, Tormek grinder, and scary-sharp over the years - all with limited success. Got a Worksharp a couple of years ago and haven't looked back, we rarely take any stones out these days. The Worksharp is simple enough to use and to teach novices to use and you have to try pretty hard to screw anything up with the machine or an edge. Put a hollow grind on the chisels/irons once in a while and renewing the edge is quick and easy - the self stick abrasives last a surprisingly long time.

-kevin

[Bryan Cramer]

Glad to see your are atempting to show the kids what a truly sharp chisel is like. All the highschool shops I know haves chisels so dull they are like flat head screw drivers!

[Steve Branam]

These are the stones I use. Note that the Arkansas is significantly more expensive than the India stones! You'll cry when someone drops one on the floor.

I would also recommend making strops by gluing leather to plywood rectangles with rubber cement, then getting either green chromium oxide compound or something like Flexcut Gold compound (there are various other compounds people like). The strop will take a "good enough" edge and refine it to something much better very easily.

[Dave Cav]

Thanks again for the follow up comments. If I was running a college program I would probably consider the Worksharp; the people using them really seem to like them. However, I think it would probably get torn up pretty quickly in a high school shop. What I'm really going to try to accomplish is to teach my somewhat more advanced students some basic hand sharpening techniques. We don't do a lot of hand work and all of our chisels are beater plastic handled butt chisels. We only have one project that requires the use of a chisel, and that's the first project all the students do, which is done with all hand tools. The chisel is used to chop out a notch after sawing both sides of the notch down to a line using a back saw and a miter box. After that I usually put most of the chisels away because they generally get pounded into random boards and bench tops. We also do very little hand plane work. Occasionally I'll get the hand planes out for a demonstration or to help someone clean up a project, but invariably if I leave one unattended, when I come back someone has taken it all apart and left the pieces scattered about. We have about 150 students in our six classes, mostly lower income students with no background in any kind of what we used to call the manual arts, and it's very difficult to keep their attention long enough to go over the finer points of hand tool use.