Article: Ashley Harwood Demonstration For CMW January 18, 2014.
February 09, 2014 16:57, submitted by Tina Collison (author: Chuck Johnson)
CMW Demonstration on January 18, 2014 by Ashley Harwood
Ashley Harwood is a full-time professional woodturner and jewelry maker located in Charleston, South Carolina. Her production lines focus on bowls of different shapes and sizes, ornaments, and jewelry. She sells her work primarily at the Charleston (SC) Farmers Market (in Marion Square on Saturdays) between April and Christmas. She brings a lathe with her to the Farmer’s Market to show folks how the items are made. Additionally, she teaches turning classes and gives club demonstrations; twenty of us were the beneficiaries of the former during the preceding two days and we all were able to enjoy the latter today.
Ashley earned her Bachelor of Fine Arts degree in sculpture and installation from Carnegie Mellon University in Pittsburgh and had her first exposure to woodturning with a class at the John C Campbell Folk School, which she took with her dad in 2009. She established her business in Charleston, Turning Native LLC, that same year. Later that year, she began her apprenticeship with Stuart Batty, concentrating on developing both her turning talent and her teaching skills. In only a short time, Ashley began teaching and demonstrating at woodturning clubs throughout the country and abroad, and she has only grown from there.
Today's demo concentrated on bowl turning in the morning and thin finial turning for ornaments in the afternoon. A DVD of Ashley's demonstration will be available soon in the library. Additional sidebars throughout the day included:
- Bowl Design Elements
- Cutting Bowl Blanks from a tree section
Ashley's bowl turning presentation began with an important sidebar on sharpening. Not too surprisingly, she uses and teaches the Push Cut method that she learned from Stuart Batty, where sharpening and turning technique are strongly interdependent. The simple description of sharpening is: Choose a bowl gouge with an elliptical flute and grind it in a “40/40” profile.
The “40/40” grind results in straight wings that are swept back at 40° from the centerline of the gouge and a consistent 40° bevel on both the nose and the wings of the gouge. The nose of the gouge is then exactly at the centerline. This is a free-hand grind. No jigs are involved; a jig-grind on an elliptical-fluted gouge gives a duller bevel angle on the nose and a sharper one on the wings, resulting in a tool that is more difficult to control.
To set up the grinder for a right-hander, Ashley recommends having the coarse wheel on the right and the fine wheel on the left. She prefers a slow-speed grinder with 8” wheels; the slower speed reduces heat and the larger wheel makes a less severe hollow grind. The axle of the grinder should be at about elbow height; don't want to be bending over to see detail while grinding. She prefers a CBN (cubic boron nitride) wheel over aluminum oxide. While expensive, it last well nigh onto forever and generates less heat and no stone dust (which is dangerous to breathe). TIP: Mount a rare earth magnet below the grinder platform to catch the steel shavings for easy clean-up.
Set the platform of the grinder at 40° to the contact point of the left-side wheel; probably need a jig or gauge to do this. Apply strips of tape or scratch lines on the platform at 40° from the top edge of the platform on either side.
A gouge that has not previously been ground to the 40/40 profile will need some initial conditioning. Place the gouge with the flute down flat on the platform and pointed directly into the wheel. Gently grind away the existing cutting edge until a noticeable flat appears from one wing through the nose and onto the other wing.
Begin by standing way around the left side of the grinder with your left elbow near the hub of the left wheel, right foot forward for balance. Align the gouge on the platform at the 40° tape strip nearer you. Rotate the gouge until the flute wall at the left wing is parallel (co-planer) to the platform. Use your left hand to hold the gouge firmly on the platform; your right hand should hold the tool above the handle. Move the gouge into contact with the wheel and, while keeping the tool flat on the platform, gently rock the handle up and down slightly until the flat is removed and sparks spill over edge. Repeat the process for the right wing using the tape strip on the right side of the platform. To sharpen the nose, start with the gouge positioned not quite as high as it was to sharpen the left wing, then twist and swing the tool over the position for sharpening the right wing. Twist and swing back and forth between the two extremes. Be gentle; go easy. Finally, relieve the edge on the heel of the gouge to let the tool get around a concave curve in the interior of the bowl.
(Note that the above instructions apply to the initial grind of the 40/40 profile and also to each subsequent touch-up sharpening. The only difference is that the initial process must remove those “large” flats.)
With the sharpening preliminaries out of the way, Ashley mounted a wet Water oak blank between centers on the lathe. She prefers harder woods because they give a nice finish, especially with negative rake scrapers, and turns mostly varieties of oak for her bowls; wet turning avoids dust. With a 5/8” 40/40 bowl gouge in hand, flute up, left hand on top, right foot back, tool handle down and against her hip, she trued up the face of the blank at the tailstock end. Speed? Fast, but safe. Just want to take off the high spots now.
[Editor's note: In the demo Ashley used CMW's straight serrated jaws, but prefers dovetail jaws. This narrative describes the latter.]
Ashley uses dovetail expansion jaws and cuts a recess in what will be the top face of the bowl, now positioned at the tailstock end. Keeping in mind the jaw size, set the gouge on the tool rest with the flute rolled over to the right, wrap the left-hand fingers over the top of the tool, and push down on the tool rest. In general, downward force on the tool rest is the only job of the left hand. When cutting on the face of the blank, however, it is necessary to place the left thumb on the tool rest behind the tool to keep it from skating. The thumb is not used as fulcrum for rotating the tool into the wood. Push the tool into the wood with the right hand well back on the handle. Make the cut toward the live center, then flip the flute over and make a cut out to meet it to widen the recess. Repeat until a rough recess is deep enough to accommodate the dovetail jaws. To cut the dovetail profile use a bedan with the nose ground to a 15° angle. Position the bedan over the tailstock with the tool handle high and push in.
Reverse and remount the blank in the dovetail chuck and bring up the tailstock for support. True up the edge of the blank: tool rest parallel and feet parallel to the lathe bed; gouge level with bevel parallel to the lathe bed; flute fully rolled over to the left with left thumb in the flute and fingers wrapped over the top of the tool putting downward force on the tool rest. The left hand is not touching the tool rest and does not guide the tool in the cut. Push in with the right hand on the handle; the gouge will follow the line of the bevel. Ashley's technique is to let the bevel glide against the wood, not ride hard on it. Finally, trim about 2” off the corner at the tailstock side; remember this is the bottom of the bowl.
Take a deep breath and re-sharpen the gouge. Expect to re-sharpen frequently.
Begin the outside profile of the bowl by rounding off the bottom. Remove the tailstock; set the tool rest at approximately 45° (it should fit nicely where you have removed the bottom corner of the bowl), plant the left foot back and right foot forward to allow for completion of the cut; tool handle should be just slightly down and swung way over to the far side of the lathe; roll the flute over about 45° (working range of the flute in this cut is between closed and half-way open) and push the gouge down onto the tool rest with the left fingers and thumb. Begin the cut near the foot area. Push in with the right hand and swing the handle. Let the bevel glide along the wood. Don't push the bevel into the wood. This will create bounce when cutting over the alternating hard end grain and compressible side grain; this may be minor at the smaller diameter of the bottom, but will get worse as the cut moves up and outward. It's important to balance the push on the tool handle with its swing to maintain the proper arc. Don't pull the tool with the left hand; its purpose is downward pressure only. Try to complete the cut from the foot to the rim in one fluid motion; proper foot placement greatly helps this. Ashley likes to curve over the top of the bowl (headstock end) just slightly.
When the outside profile roughly completed, cut a dovetail tenon in the foot section. The shoulder of the tenon should be slightly undercut so the outside edge of the shoulder contacts the face of the jaws as far out as possible. The 40/40 grind is ideal for this purpose. With the flute rolled all the way over, the combined 80° angle allows for a 5° taper on the tenon and a 5° undercut on the shoulder.
Reverse and remount the blank (in compression this time) on its new tenon and bring up the tailstock for support while tightening. Face off the top with a planing cut similar to the previous stage. Begin removing the bulk of the interior: tool handle level and out over the lathe bed; flute rolled over to the right; left hand pressing the gouge down onto the tool rest; right hand pushing on the end of the handle. Place the left thumb on the tool rest to control skating, but lift it away once the cut has started. Hollow out to about half the eventual inside depth, leaving a series of vee shaped ridges on the inside of the bowl.
Ashley makes the top of the rim slightly rounded over using a spindle gouge. Clean up the surface with a straight negative-rake scraper. Her scrapers are ground at 20° on the top and 40° on the bottom, allowing them to be conveniently re-sharpened on the 40° grinder platform. Sharpen to raise a burr on the scraper; re-sharpen when the burr is gone . . . and it won't last very long.
Returning to the bowl gouge – did you re-sharpen?? – slightly undercut the rim of the bowl on the inside. Ashley likes the illusion of thickness and weight that the wide rim provides, but the undercut and eventual thinner wall makes the bowl light in fact, both fooling and pleasing people. The wall should be slightly thicker than its final dimension; a final pass on the outside will take it down. A good size salad bowl should end up at about 3/8”.
Complete the inside hollowing. Those vee ridges make good starting point that prevents skating. Blend the top half of the wall into the bottom half so it has a smooth curvature. Sharpen the tool (yep!!) for the final cut. Start in the previous cut with the back of the bevel (no cutting) and start swinging the tool handle out over the lathe bed (gently!) until the cut begins.
The bottom of the bowl presents a challenge for any conventional bowl gouge because the bevel forces the tool to collide with the rim. The solution is to use a bottom bowl gouge. Ashley's choice is 3/4” gouge with a U-shaped flute, ground with a 50° to 60° bevel. The heavy shank and a long handle (24”) will permit the tool to hang a good distance over the tool rest while maintaining control. As before, the left hand pushes down on the tool rest (only) and the right hand plays push-and-swing. Keep the tool handle level and end the cut at the exact center to avoid a button. Using a curved negative-rake scraper held level, clean up the inside surface. It's a heavy tool; use a very light cut.
Overall, the 40/40 gouge cuts about 2/3 of the bowl depth and the bottom gouge the remaining 1/3.
The final mounting is with a jam chuck. Ashley prefers jam chucking over Cole jaws, the latter giving a less accurate mount. She also uses vacuum chucking, but accuracy is also a question and it's harder to cut all the way to the rim. For the jam chuck: mount a new blank between centers, face it off, true up the edge, and cut an expansion dovetail recess as at the beginning of the bowl work. Reverse and remount in the dovetail jaws and make a 45° cut on the end that ranges from smaller to larger than the bowl's inside diameter; leave a wide shoulder perpendicular to the lathe bed. Hold the bowl on this taper and mark the approximate location of contact. Gently re-cut the taper to a flat angle so the bowl fits snugly on the taper while firmly contacting the shoulder of the jam chuck. This will take lots of trial-and-error. Use a straight scraper for the final fit-up of the taper. If you over-cut the taper, cut the shoulder farther back and continue the fit-up.
With the nearly completed bowl on the jam chuck, Ashley uses the 40/40 gouge to shape the bowl foot from the dovetail tenon with a slight ogee. Blend it into the outside profile. Sharpen the gouge again and make the final outside cut – if possible, in one pass – from the foot and stopping just below the rim to avoid tearing. Must take off at least 1/8” to keep the tool in the cut. Stop just before reaching the rim to avoid tearing it out. Can't use the tailstock for support at this point; it interferes with the swing of the gouge handle. Finally, use a freshly-sharpened negative-rake scraper to finish the surface, including the final blend at the rim.
To complete the interior of the foot, start with shallow vee cuts to avoid punching through the bottom. Use the left thumb on the tool rest only to prevent skating. Finally, make a push-cut from just inside the edge of the foot to the center for a concave profile.
An excellent trick (OK, technique) for safely removing the bowl from the jam chuck is to cut into the jam chuck with a thin parting tool just above (say, 1/16” to 1/8”) the bowl rim. Cut deeply enough so that – after stopping the lathe – you can use the parting tool to gently pry the bowl loose. The padding created by that extra 1/16” of jam chuck material prevents damaging the rim.
Morning wrap-up notes:
Ashley usually rough turns bowls from wet wood to a wall thickness of 10% of the bowl diameter, then coats with wax and allows to dry before final turning.
During finish turning, she sands the exterior by hand and power sands the interior.
Jam chucks can easily be turned into the next bowl or re-shaped to hold another bowl.
Sidebar on finishes: Ashley exclusively uses a walnut oil finish from Mike Meredith at Doctor's Woodshop in Oregon.
Ashley left the jam chuck mounted from before lunch. She retightened the jaws before continuing; should always retighten after an idle period, but especially so with wet wood.
Then she launched into a sidebar on bowl design elements, illustrating these highlights:
- Commercially, it's important to distinguish from cheap, mass-produced Pier One and Target products.
- Bead on the side: Complete the outside profile with push-cuts up from the bottom and down from the rim, but leave a 1/4” x 1/4” band projecting from the surface. Ashley uses the Stuart Batty Vortex tool to form the bead. Start with the handle level at 45°; drop the handle and roll the Vortex tool over to cut one side. Repeat in the opposite direction and finish with a negative-rake scraper. Can't do this with a spindle gouge; the end grain will grab the tool and cause a catch.
- Shallow cove at rim: This element looks like a coved belt. Leave a wide, flat section just below the rim and proud of the lower outside profile. With a 40/40 gouge, gently scoop out a cove from the flat with a push-cut up from the bottom edge of the belt. It's OK to cut uphill in this case because the slope is so slight. Finish with the negative-rake scraper.
- Foot: In addition to the ogee shape from the morning, can also form the foot with a shallow cove to match the belted effect at the rim.
- Small cove: Just a shallow cove cut with a round negative-rake scraper. Highlight with a sharp groove above and below.
- Or just a series of sharp, shallow grooves: Use the point of the Vortex tool; it leaves very little tear-out. Space the grooves evenly or graduated.
- We all ask ourselves, “What details should I include?” The best answer is “just make it look good.” The best way to achieve this is to draw it on paper.
- We all are driven to turn the largest possible bowl from the blank. Don't succumb to this at the expense of a pleasing profile.
And now for something completely different, Ashley shifted to spindle turning. Two immediate changes she made were to remove the center tip from the live center and shift the lathe to the higher speed range. She mounted a 3” x 3” x 5” blank between centers. Some debate arose over the type of wood; consensus was reached that its botanical name was dufledia roadsidia, the common name being FOG wood (“found on ground”). Ashley thought it looked like sycamore; some speculators in the cheap seats suggested it might be hickory.
Ashley roughed the blank to a cylinder with a spindle roughing gouge. Hold the tool from underneath with the left thumb and fingers, handle level and against the body, tool perpendicular to the lathe bed, feet parallel. Shift weight from side to side to slide the gouge over the tool rest and along the length of the blank. Roll the tool to expose all of its cutting edge to the wood (and legitimately delay sharpening). The spindle roughing gouge can put on a pretty good finish by swinging the handle 45° away from the direction of travel along the tool rest to use the right wing like a skew.
Turn a tenon, then remount the blank in the chuck and true it up.
Using the 40/40 bowl gouge, Ashley illustrated a number of standard spindle cuts:
- Can face off the end of the blank by orienting the bevel perpendicular to the lathe bed; to do this, swing the tool handle to the right so it's at 40° to the lathe bed. Use the left thumb on the tool rest to control skating. Stand with the left foot forward and right foot back. Push in with the right hand and remove the thumb as soon as the cut starts.
- Similarly, cut a straight half-vee on the end by orienting the gouge bevel at the desired angle.
- Set-up for the half-cove is the same as for facing off (bevel aimed straight in), but after the cut starts, use a push-twist-swing motion to complete the cove. If you see evenly-spaced lines in the cut, they come from the heel of the bevel compressing the wood.
- Begin turning a half-bead with the handle low and almost perpendicular to the lathe bed – it should be pointed slightly to the right, then slowly lift until the gouge starts cutting and complete the cut with a push-twist-lift-swing motion.
Ashley's primary spindle turning work produces finials for a sea urchin ornament. One item she neglected to bring was a piece of 1/8” dowel, so she turned the blank down to that diameter with the bowl gouge. In the final cut she used the edge of the gouge as a skew for a good finish.
Her method of assembling the ornament is to have the finials fit snugly to the shell without being glued to it. For success, this requires some sort of filler in the shell cavity, so she sprays in expanding insulating foam for doors and windows; it's lightweight and reasonably rigid. Keep some acetone available for clean-up. When ordering, plan to buy extra shells: some will be broken, the count may be off, and you will slop some of them up because the foam is very hard to control. Use a cone-shaped stone in the drill press to grind out the opening in the shell.
Ashley mounted a 1” x 6” piece of ebony in #1 serrated jaws and turned a 1” long notch about 1: from the tailstock end, then parted it in the middle of the notch to make a long section and short one, each with its own tenon. Flip the long section around in #1 jaws, then turn a short tenon to fit inside the bottom opening of the shell and drill a 1/8” hole a short distance into that end with the drill hand-held in a pin vise. Reverse the blank and bring the tailstock up for support. Rough down the diameter a bit and remove the tailstock. With a spindle gouge, reduce the last inch or so and turn a 1/8” diameter half-cove on the end and a half-bead just above it. Work very delicately. With the 40/40 bowl gouge and working in about 1” lengths, thin down the finial to less than 1/8” (closer to 1/16”). With about 4” thinned, turn a bulb shape and double cove and bead just under the tenon and blend the bulb into the finial.
Now it's time to sand so turn down the speed. Ashley uses a progression of 150, 220, 400, and 600 grit in small sheets. To sand the long straight sections fold the paper with the bottom edge sticking out a little more than the top edge, abrasive side out. Fold again and gently pinch around the finial to sand. Use the projecting edge of the paper to sand the groves and other tiny details that have sharp interior corners; the second layer gives support, but its abrasive surface stays out of the way. Roll another piece of sandpaper with the abrasive side out to sand the coves.
Ashley uses a finish of walnut oil and microcrystal paste wax from Doctors Woodshop. Turn the lathe off and apply with a clean cloth. Turn the lathe back on to polish. The tenon fits into the shell hole.
Mount the remaining small blank in the chuck as the finial cap and drill a 1/8” diameter hole about 1/8” deep. Using a small numbered drill in a pin vise, drill a hole the whole length of the drill (about 1”). Turn the cap with a design that echoes the elements of the bottom finial.
To assemble, glue the dowel section into the 1/8” hole in the bottom finial. Feed a loop of monofilament fishing line through the small hole in the cap and tie with a knot that won't slip back through the hole. Feed the dowel up through the shell (and its interior foam) and cut off about 1/8” above the shell. Glue the finial cap onto the dowel and admire the result.
Final thought on delicate finial turning: Don't do it when you're angry.
Sidebar tips on cutting a log for bowl blanks:
- Eliminate the pith from all blanks. It's a guaranteed source of cracks.
- Blanks cut off-center in the cross-section are susceptible to warping and cracking.
- Blanks with the foot at the tree center (near the pith) give natural edge bowls with a concentric grain pattern.
- Blanks with the rim at the tree center yield bowls with an hourglass grain pattern.
- Blanks from quarter-sawn wood give bowls and platters with a straight grain pattern.
- “Feather” is a grain pattern that occurs in the Y-shaped crotch of a tree and only quite near the centerline. Slice a crotch section through the three-point plane connecting the pith of the trunk below the crotch and the piths of the two branches above. This will yield two thin blanks suitable for platters.
- Blanks cut from burls yield an “eyeball” grain pattern.
A DVD of Ashley's Demonstration will be available soon in the Library.
Submitted by Chuck Johnson, photos by Tina Collison