If the edges of your carving chisels are in rela-tively good condition, all you may need to sharpen them is a set of oilstones or waterstones and a leather strop. But if an edge is nicked or ragged or if you want to change the bevel angles, start by grinding the bevels evenly on the side of a bench-grinding wheel (A). Don’t use the face of the stone because it will produce a hollow grind.
Instead, hold the tool against the side of the wheel to produce a flat grind. If the end of the chisel is uneven, grind it square first.
[VARIATION]You can use a 1-in. belt sander to grind the bevels. Be careful not to overheat the edge, and check your progress frequently to keep the two bevels at the same angle.
Once the bevels are established, hone them on waterstones or oilstones. If you are going straight to the stones without using a bench grinder, square the end by drawing it across the face of the stone, then hone the bevels flat on the stone (B). Take care not to rock the tool as you hone, which would round over the bevel (C). Try to use the full surface of the stone to minimize wear, especially when sharpening narrow chisels.
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B
C
VA R I AT I O N
Repeat on the other bevel, and switch to progres-sively finer stones until you have polished the edge with a 4000- or 8000-grit stone (D) and all the marks from previous stones have been erased. The last step is to round over the sharp heel of the bevel. Work the area until the sharp transition is softened, but in the process be care-ful not to round the edge you have just sharpened.
You’ll get the best edge by finishing up with a leather strop charged with honing compound (E).
Pull the tool down the strop using moderate pres-sure, and test your edge on a scrap of wood.
An alternative is to use the Tormek Sharpening System, which includes both a leather strop and a grinding wheel (F, G). A major advantage of the Tormek is that it will not overheat the steel. Use the side of the slow-speed grindstone to shape the bevel. Take the time to get as smooth a finish as possible on the grinding wheel or it will be dif-ficult to get a nonrippled surface from the strop-ping wheel. Hone on waterstones if necessary.
Charge the leather strop with honing compound and a few drops of oil, and work both bevels of the chisel from heel to edge until it’s razor sharp.
D
F
G E
V-Tool
V-tools are the most difficult of all carving tools to sharpen. There are two cutting edges, not just one, and they must be kept straight, square, and uniformly thick as they are honed. In addition, the corner where the two cutting edges meet can be tricky to sharpen without wearing away too much metal and collapsing the edge.
Mistakes happen quickly on a power grinder, so it’s a good idea to switch to oilstones or water-stones after doing just the rough shaping with a bench grinder or belt sander. Edges should not be hollow-ground. So if you use a bench grinder, do the work on the side of the wheel instead of the face. A 1-in. belt sander with a 100- or 150-grit belt is more forgiving than a bench grinder, and it will produce a flat bevel.
First, square the end by pushing the tool straight into the sanding belt or abrasive wheel (A) with gentle pressure. Looking at the squared end will tell you how much, and where, metal should be removed to produce uniform bevels. If the blunted end of the tool is not the same thickness from edge to edge—that is, if the flat tapers in width—
grind away material from the thick area by hold-ing the flat against the platen on the belt sander or against the side of the stone if you’re using a bench grinder. What you are trying to produce is a flat on the end of the tool that is the same width (B). Once this has been established, you can grind both bevels, using either a bench grinder (C) or a belt sander (D). Stop grinding before the flat disappears.
Next, grind the basic angle of the keel, the area where the sides, or wings, of the tool meet in the middle (E). Make sure you can see what you
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C
E D B
are doing. Using the side of the bench grinder gives you a good view from the back of the tool.
Be careful not to grind too much material away.
Grind the same angle on the keel as you did on the bevels.
Work the inside of the V-tool, making sure the inside surfaces are flat and smooth. If the surface is pitted or uneven, a coarse India triangular slip-stone or a diamond file will remove material quickly. Then hone the surfaces smooth with a fine India slip (F). Be careful to hone each side evenly. Keep an eye on your progress by check-ing the flat on the end often. The line should be straight and the flat part uniformly thick.
Polishing the inside faces of the tool with finer abrasives will produce an even better edge.
Arkansas slipstones can be useful, but they may need to be shaped to fit the inside profile of the V precisely. Another way is to plane a strip of wood to fit the inside profile exactly (G, H) and charge it with honing compound (I). Prop the tool on your bench or a block of wood, and work the wood slip over the inside surfaces. This approach will give you excellent results.
After finishing the inside, go back to the bevels.
Hone the bevel starting with 220 grit or your coarsest waterstone (J). Keep working on the coarsest grit until the flat line of light on the end of the tool almost disappears. Be careful not to round the bevels while honing. The hardest part is to get the bevel even all the way across. It’s easy to hone more aggressively near the middle of the V, which will cause the edge to break
F
G
H
J I
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through (K). If that happens, square up the end again (L) on a stone and go back to work.
When you have the edges even and the flat reduced to a hairline, step up to the next grit and hone to remove the flat completely. Finish honing on your finest stones.
The sharp heel between the bevel and the tool created during sharpening can mar the work-piece. Slightly round the heel on a stone, then make sure to polish this area as well. The final step is to hone the keel by rolling the tool as you travel the length of the stone (M, N, O). Uneven spots can be honed with a back-and-forth motion.
When you’re finished, the outside of the V should match the small radius on the inside. Strop the bevels and the keel with honing compound on a leather or wood strop for a mirror polish (P).
Once the tool has been prepared properly, you shouldn’t have to do much to the inside surfaces when resharpening other than to remove the wire edge created during honing.
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N
P O
M K