Sharp tools are essential for effectivewoodcarving. Even though manymanufacturers of woodcarving tools

supply their products ready sharpened, Iwould recommend that you spend time,right from the very start, learning how tomaintain the cutting edge to get the bestresults from your tools.

If your tools are not razor sharp, it willmake learning to carve difficult and frus-trating, so I can’t stress how important it isfor you to master this.

To begin, let us consider how carvingtools are manufactured. The steel bladesof carving tools undergo a heat treatingprocess called tempering. This processmakes them very hard and durable.However, if the tools are heated exces-sively during the sharpening process, theymay lose their tempered quality andbecome brittle.

Many woodworkers have benchgrinders in their workshops which arevery effective at removing metal quickly.The one drawback, however, is that if

used incorrectly, they can also burn yourtools very quickly.

Re-grinding your tools should be a lastresort, as the majority of maintenance onwell-kept tools can be done by honing thecutting edge with bench stones andstrops.

There are many different sharpeningsystems available on the market andmany will produce razor sharp results.However, regardless of which system youchoose, you will need an understandingof the basic sharpening principles.

Sharpening AnglesThere are two main angles to consider

when sharpening your carving tools. Thefirst is the blade angle, which is used todescribe the angle of the cutting edge inrelation to the centre line of the tool(Photo.1).

For the majority of carving tools, theblade angle is kept at 90° to the centreline of the tool. The cutting edge needs tobe completely flat and the outer tips of thecutting edge should be intact, not round-ed over.

The second angle to consider is thecutting edge angle or ground edge angle(Photo.1a). The cutting edge angle of yourcarving tools will vary anywhere between20° to 30°.

This angle should vary in relation tothe density of the timber that you are carv-ing. A 20° angle will give you a far keeneredge but it will be more susceptible todamage. For smaller finishing tools, or ifyou carve mostly softwoods, a 20° anglewould be ideal.

If you were to use a mallet to removelarge quantities of hardwood, such asJarrah, then a greater angle closer to 30°would be required to maintain a function-al cutting edge. As a general rule, the

harder the timber, the greater the angleshould be. For a multipurpose tool aim for25°.

Incorrect sharpening techniques canlead to defects such as chips along thecutting edge, rounded tips to the cuttingedge and the blade angle is no longer at90° to the centre line of the tool. Wherethe cutting edge has become roundedrather than a clean straight angle, this iscaused by poor honing techniques.

Traditional Sharpening TechniquesWith a badly damaged tool, the only

way forward is to regrind the blade angleand then the cutting edge angle.

When using a dry wheeled grinder, itis essential to keep the steel cool at alltimes. This can be done by applying min-imal pressure with the blade onto thegrind stone. It is also important to dip thetool in water after each pass on the

Photo.3: Presenting the blade to thegrinder wheel

Photo.4: Multiple flats caused by rotatingthe gouge unevenly while grinding

Photo.5: A correctly ground cutting edgeangle on a gouge

NUMBERSPt.2 — Sharpeningby Mike Davies

Woodcarving By

Photos.1 & 1a: Blade angle (90°) left andcutting edge angle (20-30°) right

Photo.2: A blade after being ground at90° to the centre line of tool

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machine. When using a grindstone,always wear eye protection, keep yourfingers away from moving componentsand make sure all loose fitting clothing istucked away from the machine.

Good lighting is also important so thatyou can see your progress as you shapethe cutting edge.

Ensure the grinding wheels on yourmachine are clean, flat across the faceand running true. With the grinderswitched off and unplugged, adjust thetoolrest so that it is close to the wheel androtate the wheel by hand to make sure itruns at a consistent distance from the toolrest. If not, the wheel will need dressing.

The first task is to grind the bladeangle. The goal is to obtain a perfectly

straight line at 90° to the centre line oftool. Note in Photo.2 how all the chips inthe cutting edge have been ground awayand the tips of the tool are clean andintact. You will also see how a flat hasbeen created along the cutting edge. Thisis often referred to as a flat-line or line-of-light.

The next task is to create the cuttingedge angle. Some carvers make a series oftemplates to help grind to a precise angle,but the simplest approach is to draw sev-eral angles on a piece of paper and usethem as a guide.

Use your forefinger and thumb topinch the blade of the carving tool, so thatyour forefinger forms a stop against thetoolrest of the grinder (Photo.3). The trickhere is to maintain the same grip on thetool from the start of the grind to the fin-ish. In this manner your finger will help toachieve a consistent angle.

Remember not to change your grip onthe tool when dipping the blade in water.

This technique applies to both flat cut-ting edge chisels and curved shapedgouges. If you are grinding a curvedgouge, then rotate the tool as you pass theblade across the grind stone. Try to avoidgrinding numerous flat spots around theedge (Photo.4). You need to create a con-sistent ground edge angle around the cir-cumference of the gouge (Photo.5).

Continue grinding a consistent angleuntil you reach the stage where the flatline is almost completely removed. Thegoal is to have a consistent flat line that is

less than 0.1mm in thickness along thecutting edge. Avoid grinding through theflat line as this will create a tool with awavy cutting edge.

HoningHaving set the cutting edge angle, the

next step is to hone the blade.There are numerous sharpening stones

available — silicone carbide, naturalArkansas stones and diamond sharpeningsystems to name but a few. Whicheverone you choose, the same techniques willbe required.

I recommend having two stones forhoning. The first can be used for curvedgouges and the second for flat cuttingedge chisels.

There are two schools of thought forthe honing angle. Many like to slightlyincrease the honed angle from the groundedge angle. The benefit is that you can beconfident about putting the cutting edgein contact with the stone, as opposed tothe back edge of the ground angle (alsocalled the heel). The downside is that youcan quickly create a convex shape to theground bevel and to remove this willrequire a fresh re-grind.

I generally prefer to make the honedangle as close to the ground angle as pos-sible (Photo.6).

Honing Flat ChiselsPosition the sharpening stone on your

workbench with its length running away

Photo.6: The author prefers to make thehoned angle as close as possible to theground angle

Photos.8-10: Left to right — the sliding and rotating movementrequired to provide an even hone along the circumference ofthe cutting edge of a gouge

Photo.7: Honing a flat chisel

Photo.9

Photo.10

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from you. Add a little oil or water to thesurface according to the manufacturer’sinstructions.

Place the chisel onto the stone’s sur-face at the required angle and slide it backand forth in a continuous motion(Photo.7). It is essential that the sameangle is maintained throughout thisprocess. Continue until you are able tofeel a small ridge of steel that will form onthe opposite side of the cutting edge. Thisis called a burr and needs to be removedusing a slip stone.

Honing Curved Cutting EdgesWhen honing a gouge, fluter or veiner,

place the stone horizontally in front of

you and add oil or water as appropriate. Place the gouge at the required angle

on the stones surface and slide it from sideto side along the stone’s length. As youslide, rotate the handle of the gouge sothat the curvature of the blade receives aneven grind (Photos.8-10). Be careful notto hone away the corners or tips of thecutting edge, which need to be kept at asharp 90° angle to the shank of the tool.The shank refers to the entire length of thesteel blade between the handle and thecutting edge.

If the corners become rounded, then itis probably due to the gouge being rotat-ed too far. It may be helpful to practise thesliding motion initially on a flat piece ofsoftwood.

When using the stone, continue theprocess until you can feel the burr on theinside of the gouge’s curve, opposite theground edge angle. This should then beremoved with a slip stone.

Using a Slip StoneSlipstones are used to remove burrs

and provide a finer cutting edge. The slip-stones should be a finer grade than thebench stone and when working withcurved cutting edges, they must fit insidethe tool profiles.

Hold the slip stone between your fin-gertips and thumb and rub the length ofthe slipstone on the inside contour of thecarving tool. The objective is to removethe burr.

Some carvers like to form an insidebevel, though I prefer to avoid this.Therefore I keep the entire flat face of theslipstone rubbing against the length of the

shank (Photo.11).After removing the burr, you can then

use the slip stone to create a finer cuttingedge. To do this, simply use the flat side ofthe slipstone to rub ‘up and down’ thecutting edge (Photo.12). Be sure to main-tain a consistent angle, ie. the honed edgeangle. You do not want to round over thesharp cutting edge.

Stropping the BladeThe final process involves a leather

strop, similar to one that a barber woulduse to refine the edge of a razor.

The leather should be impregnatedwith a fine abrasive compound, such asjewellers rouge. Run the outside andinside faces of the cutting edge down theleather strop to produce a polished cut-ting edge which should produce razorsharp results (Photo.13).

Testing the Sharpness of Your ToolsTest the sharpness of your tools by

using them on a piece of scrap carvingwood. Try sliding the blade through thetimber, both with the grain and across it. Ifyou have a razor sharp cutting edge itshould glide effortlessly through the tim-ber, like a hot knife through butter.

Take a close look at the finished cut. Ifyou have tiny ‘white’ drag marks in thetimber, there is a defect in the blade,which needs to be removed by furtherwork with slipstones or even honing.

The goal is a polished cut straight from

Photo.11: To avoid an inside bevel, hold the shank flush againstthe length of the slip stone when removing the burr

Photo.13: Running the outside and insidefaces of the cutting edge down a leatherstrop

Photo.14: Two test cuts — the one on the left is a perfect pol-ished cut while the one on the right has fine drag marks causedby the sharpened edge not cutting cleanly

Photo.15: With a wet stone system, use an angle setting gauge for preciseresults

Photo.12: Refining the honed edge witha slip stone

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the blade. In Photo.14 there are two cuts.The one on the left is a polished cut andthe one on the right has fine drag markscaused by imperfections in the cuttingedge. The tool that created the drag markswill require further work until the cuttingedge can produce a clean and polishedsurface.

A video presentation on the traditionalmethod of sharpening carving tools canbe viewed on my WoodcarvingFoundation Skills DVD, available throughThe Australian Woodworker Mail OrderBookshop (details at the end of the arti-cle).

Wet Stone Sharpening SystemsA wet stone sharpening system is an

ideal method for grinding and honingtools to a razor finish. The system carrieswater to the blade as it is being ground,making it impossible to overheat yourtools.

You can produce accurate angles

effortlessly, regardless of the shape oftool, using an angle setting gauge(Photo.15).

Most wet stone grinders are availablewith a host of jigs (Photos.16 & 17), but itis important to consider the whole systemwhen making your purchase. The gradeand quality of the stone and jigs, and theavailability of accessories will affect theperformance and versatility of the sharp-ening system.

Most wet stone sharpening machinesare fitted with a honing wheel, allowingyou to use the same jigs when switchingfrom grinding to honing. This allows youto ensure the honed edge angle is identi-cal to the ground edge angle.

A good quality wet stone grinding sys-tem should enable the novice to producea mirror finish and a razor sharp cuttingedge, quickly and consistently.

Further Information You can view sharpening tutorial

videos for flat chisels, gouges and V-tools,using a wet stone sharpening system, atwww.recordpower.com.au. Go toWoodworking Machines, Sharpening &Grinding, Sharpening Systems and thenclick on the video’s tab of the WG250.

This series of Woodcarving byNumbers articles is based around thetools found in the the Record Power 12Piece Carving Tool Set. This is availablewith the bonus Woodcarving FoundationSkills DVD and booklet for RRP $132.00from The Australian Woodworker MailOrder Bookshop, pp.82-90, Ph: 02 47592844 or from Record Power stockists.

Next Issue: Flat Carving

Use the QRcode to accessinformation onthe Carving Set

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Photo.16: Sharpening with a gouge jig Photo.17: Sharpening with a straight edge jig

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