Sunday, April 25, 2010

The Grimsdale Method, part 2

(Go back to part 1)

Go to the video at the bottom of this page.

After my success using Jacob Butler's convex bevel method with my DMT stones, I ordered a set of three 8" x 3" x 1/2" Norton India stones from ($47.91 for all 3), along with a quart of Norton honing oil. I chose the 3" width because I have some plane irons that are over 2" wide, even though that meant I had to get thinner stones. I held off getting a matching hard Arkansas stone due to the cost ($79.99), since I had a tiny one I had gotten at a knife show 30 years ago. Ordered Saturday night, they arrived Thursday evening, so I gave them a quick try.

WOW! I don't know what kind of crappy oilstone I had tried in the past. These were far better. I didn't even bother with the coarse stone at first, the medium and fine cut so fast.

I tried them on an iron from a small wooden coffin smoother and a 3/4" chisel. The Arkansas stone gave them an extra fine edge, although its small size made it hard to use. Based on that, I decided it was worth investing in the full-size hard Arkansas stone from It arrived just as quickly as the others had. These stones are also available from Tools For Working Wood; their shipping is also fast.

My completed set of sharpening supplies: oil, 3 India Stones, hard Arkansas stone, and a scrap of leather for a strop.

The sharpening setup, clockwise from top left: the coarse, medium, fine, and Arkansas stones and oil, a protractor set to 30 degrees for checking progress, a bevel gauge set to the same angle to stand up as a visual reference while working, a board held down securely to protect the bench from the messy oil and swarf, the leather strop, a disk magnet wrapped in foil to clean off the stones, and an engineer's square to check for square grinding.

The magnet was Jacob's idea for cleaning iron filings off the stones without wiping off all the oil. It works pretty well, although it's difficult to clean them off the magnet itself if you don't cover it. The foils works, but wears through easily. Sharpening is messy, so I wore an apron and kept a stack of paper towels handy.

A bit of terminology here. I've seen the flat side of a chisel or plane iron opposite the bevel called different things: the flat, the back, the face. Not sure if we're coming or going here! I'll use the term face.

The sequence I followed was to work bevel, then face, vigorously on each progressively finer stone, then strop at the end, starting with whichever stone was dictated by the initial condition of the blade. The edge can be maintained thereafter with just the fine India and hard Arkansas stones.

The results using these were superb. See the video at the bottom of this page showing them in use on a flea market Stanley #4 and another old Buck Brothers chisel. The photos below repeat the process with a Stanley #3 and an old chisel stamped "DUNLAP" and "Germany".

I flattened the plane a bit on the sandpaper-covered granite reference plate. I've started the iron bevel on the coarse stone, so it's already cleaned up a bit.

Working the plane iron bevel on the coarse stone. This didn't take much work, since it was in reasonable shape. Note the bevel gauge serving as visual reference to the side.

A few steps later: working the face on the fine stone. Working the bevel raises a burr; working the face turns the burr into a wire edge which will come off in the oil or on the strop. You can also see where I've used the magnet to clean off the coarse stone.

Stropping after wiping off the oil, alternating sides for several strokes each. This removes any remaining bits of wire edge.

I put the plane back together, adjusted it for smoothing, and tested it on the face of a scrap of cherry.

The resultant cloud of fine smooth shavings. Now that's pure joy!

The chisel edge. This is going to take some work.

The chisel had been ground at about 33 degrees and was dubbed over and slightly nicked. Not quite bad enough to go to the powered grinder, but close. I spent about 10 minutes working it on the sandpaper and reference plate, just going for metal removal to clear the dubbing and nicks, working to just under 30 degrees.

The edge after going through the four stones and strop. It's hard to photograph a sharp edge!

The chisel taking a nice fine pine end-grain shaving.

Some of the editing in the video below is a little harsh because I was trying to stay within YouTube's 10-minute limit. Audio is mono only (I need to figure out how to duplicate the mono on both stereo channels).

The end result is that I'm extremely happy with this method. It's fast and effective for various sharpening media; I have no doubt it would work just as well with waterstones. It's completely portable with fast setup. The India and Arkansas stones should last me 30 years, which is one reason I chose them over waterstones. While waterstones may cut faster, they also wear faster. These stones get the job done just fine with only a few minutes of effort. So no fussing around, back to working wood quickly.

I think I finally have my recipe for hand sharpening. Thanks, Jacob!

(Continue to part 3)

Sunday, April 11, 2010

The Grimsdale Method

Over in the Woodwork UK and UK Workshop hand tool forums, there's a fellow who goes by the moniker Mr. Grimsdale. His real name is Jacob Butler, a joiner and furniture-maker in Derbyshire. His website is

Jacob promulgates a freehand sharpening method that is a bit controversial (if I may be permitted an understatement). He refers to it as the convex bevel.

To some, this is heresy; one should never round-over an edge! But this is a controlled rounding over from the top approaching the target edge angle, not a dubbing over. He argues that it's simpler and faster than trying to maintain a consistent flat bevel or use a jig. I'll let his description speak for itself here.

Sharpening is one of those things like dovetails where everybody seems to divide into armed camps and glare at each other menacingly. Put five woodworkers in a room together and they'll argue ten ways about the proper technique. So Jacob gets a lot of heat for this method. If you browse the forums, you'll see multiple references pro and con (and you'll feel the heat).

For those who like to put microbevels on their edges, this is like an infinite series of microbevels, where the lead microbevel is at the desired 30 degree angle. In mathematical terms, where two or more flat microbevels approximate a curve as step functions, this is the actual curve as a continuous function.

In addition to the basic method, he also came up with a simple jig for applying heavy pressure to the edge. Wait, a jig for jigless sharpening? Well, that's another heat source, so let's just move on.

I'm always happy to try something out if it looks like it'll improve my hand tool skills. Maybe I'll stick with it, maybe not. Part of the reason sharpening is such a touchy subject is that it's a critical skill that easily becomes an obsession unto itself. We really need something that's effective. So I gave it a try.

My initial attempt was on my sandpaper-on-glass setup, based on Mike Dunbar's Sensible Sharpening method: 3 grits of PSA sandpaper (80, 120, and 320), followed by 3 grits of automotive wet-dry sandpaper (600, 1000, and 1500). The results were excellent with an old Buck Brothers chisel and a plane iron.

The resultant chisel edge.

Cherry endgrain shavings. I was able to mark a line and shoot down to it freehand with this chisel, just as good as a shooting board.

Next I tried my DMT dual sharpening stones on a mixed set of beautiful old Stormont and Marples paring chisels I had gotten from Patrick Leach. Some of the chisels were very sharp, others fairly dull, and a couple seriously dubbed over.

I had stopped using the DMT stones because I had been using them with a jig and wanted to get away from dependence on it, and the sandpaper was faster for really heavy refurbishing (yes, I'm making the expensive rounds of sharpening systems). But the results were equally impressive using the DMT black, blue, red, and green sequence. For a couple of the chisels, I had to go back to the 80-grit sandpaper first; for some others, I just had to do DMT red and green. All of them were able to pare end-grain.

The last experiment was to use Jacob's jig on a chipped iron from an old Stanley #7 jointer. The jig allows you to apply a lot of down-force to the end of the iron. It supplies the leverage for a plane iron that the handle supplies on a chisel.

The plane is a bit rough but usable. No real rust, but the tote is broken off at the tip and the iron is a bit chipped, as is the cap iron.

Close-up of the iron showing the chipped edge that needs to be removed.

Mounted in the jig, bevel down. I put about 3 minutes of labor into the jig. First time using my North Bros. Yankee No. 41 push drill with the little shell bits, patent dates on it "JAN 25 98-OCT 29 01".

Working it vigorously up and down the length of the 80-grit paper until I had cleared the chipped end. This took about 5 minutes and raised a nice burr. The jig also helps protect your fingers; the metal gets hot!

The dip move that forms the convex bevel is pretty easy to master, and hardly requires conscious effort (which probably explains why so many people have trouble maintaining a flat bevel freehand, part of Jacob's basic premise).

The convex bevel after the 80-grit sandpaper. I added just the slightest camber, easy to vary the pressure with the jig.

After flipping the iron over in the jig, working the flat side-to-side for a minute or so until the burr is gone.

At this point the heavy work was done, so I removed the jig and switched to the DMT stones. I could have left the jig on to use with them, but I'm going for freehand here.

Flattening the chip-breaker edge.

The DMT stone holder is a variation of the one I saw Deneb Puchalski use at the Lie-Nielsen 25th-anniversary open-house. I've removed the jig-setting stops that I had originally built, and added a piece of leather as a strop in their place, per the recommendation at Tools For Working Wood/Museum of Woodworking Tools.

Full-speed convex-beveling up and down the length of the DMT black.

Up and down the edge of the stone to polish the flat.

Pulling a few quick strokes on the strop, alternating each side, after completing the DMT green.

The final edge after about 5 minutes total to go through the DMT sequence.

Now for the moment of truth: the proof is in the shavings. I have a scrap of quartersawn white oak from my current project that I've been using as a practice piece.

The jointer takes nice long smooth shavings, good enough for my work.

Close-up of the shavings.

It took less than 15 minutes total to get from chipped iron to smooth shavings.

My conclusion: this is a simple, fast, effective technique. Good enough that it's encouraged me to give old-fashioned India stones another try (since the old fellers didn't have these high-tech diamonds; would Roy allow DMT's in his classroom?). I've ordered a set of three Nortons, along with a quart of their honing oil. We'll see if I can achieve the same results with roughly the same level of effort using less expensive abrasives. Sandpaper sounds like a cheap system, but I find myself using it up faster than expected.

(Continue to part 2)