Notes from Clead Christiansen's Beginning Woodturning Class
From 11 to 13 April 2001, the Beginning Woodturning class at Craft Supplies in
Provo, Utah was taught by Clead Christiansen. These are notes I took. I do not
guarantee them as to accuracy nor completeness. They are expressed as I wish
and Clead isn't responsible for anything I say here.
Curriculum and Schedule
- Day 1Spindle Turning
- Day 2Spindle Turning and Bowl Turning
- Day 3Bowl Turning
Tools
- Position tool rest such that gouges and skews cut above the center of
the turning stock.
- The lathe should be elevated such that the spindle is at the same
height as the turner's elbow.
- Various methods of tool control, including
- Pinch tool between thumb and forefinger
- Position left hand over and grip tool near tool rest
- Place fingers behind and around spindle with thumb on tool
- Use parting tool to cut just above center.
- Tools for spindle turning
- Parting tool
- Skew (preferably with rolled edge to avoid digging into tool
rest)
- Gouge, shallow (we used what was basically a round-nose scraper
with a little longer bevel than ordinary scrapers have)
- The skew works on upper quarter closest to turner, long point up (for
skew cuts), handle down, correct angle (maybe 45° respective to
floor). RUB THE BEVEL. Gradually raise handle to bring cutting edge bear
on surface where it will begin cutting in the manner of a knife peeling
an apple in one long cut.
- The roughing gouge MUST NEVER BE USED FLAT and never for shaping. It is
unsuitable for bowl roughing particularly because of the direction of the
grain.
- Tools for bowl turning
- Bowl gouge, which is very deep.
- On occasion, a shallower gouge. Using a more shallow gouge inside
the bowl usually leads to snagging with ensuing fright, damage to
surface and occasionally to bowl explosion.
- Let the gouge bite and begin to cut before beginning to move
it. DON'T JAM GOUGE INTO THE WORK.
- Watch that the tool rest not be too low.
- Anchor and pivot with left hand; sweep gouge with right in coring
the bowl. This reduces "ribbing" (uneven cuts resulting in little
"ribs" inside the bowl).
- The adjustable-jaw chuck is most reliable when not only the jaws grip,
but the bowl is flat-turned so that it bears on the flat end of the jaws
as shown here by the arrow (except that in this picture, the jaws
appear beveled in meeting the bowl).
Spindle Turning
- Roughing out the spindle
- The larger the flat surface on an unrounded piece of stock, the
faster it should be turned when roughing because faster speeds make
it "rounder."
- Knock off corners of square stock at 2500 rpm.
- Make short cuts starting near (but not at) end and cut to end
from center.
- Illustration.
Use a "roughing gouge" as shown here. The tiny curved lines here
show scooping cuts to be made successively in stock to knock off
the corners making the stock into a spindle. The edge of the gouge
is shown here (the heavy U-shaped line) in proper position for next
cut. Gouge should be held parallel to floor, on side (flute facing
left or right, but never turned up or down more
than a little bit).
- Don't cut past end coming back onto stock. (Cut only from center
to end.)
- When using skew to mark or make cuts similar to how a parting
tool cuts, position the long point down against the tool rest. If
the bevel isn't rubbing (or the skew is tipped to one side), the
skew will catch and cut a spiral in the stock.
- Spindle cuts. General turning moves or cuts, more straight-forward in
spindle and less obvious in bowl turning, are
- Bead
- Mark the bead with a skew (long point down). Knock the
corners off with the skew.
- Start gouge out flat in bead center and roll to one side
into vertical position.
- Repeat for other side.
- Wood fibre is compressed rather than torn out (as it would
be if cut was attempted from side to center.
- As the gouge is rolled to one side, the end of the handle
should be brought up.
- The skew may be used to do a bead; keep the long point down.
- RUB THE BEVEL.
- Cove
- Start gouge out standing up, then dig down into cove being
created. Do not go back the other way. The cut is made with
the leading edge in a scooping action.
- Caution: if gouge is started absolutely vertically, it may
turn into a skew and travel or spiral away.
- Position gouge vertically on the other end of the cove and
repeat.
- The skew may NOT be used to do a cove.
- Using a scraper to do a cove results in checking the wood.
- Fillet (not explained much)
- A fillet is a shoulder, usually flat (otherwise it becomes
a bead or a cove), separating beads and coves.
- Use a fillet to separate features on a spindle if that will
help make those features crisper (more delineation).
- Use a gouge carefully or a skew very carefully to make a
fillet.
- Ball, egg or fruit turning
- These forms are like large beads.
- Use "skew scrape" technique with spindle gouge to adjust
diameter. This involves pulling gouge backward holding anchor hand
(on end of handle at hip) steady while tool is held with hand over
top tightly against rest. The fingers pull the gouge along in the
direction of the flute. For a right hand on top of the tool, this
would be with the flute facing right and the right hand pulling the
tool to the right.
- The ball proves good form in bead making because it requires the
gouge to be moved accurately over a long distance without the
benefit of merely pivoting it on the tool rest. Good form includes
- Good tool control; the hand that is on the tool rest
holding the tool does it very tightly so that the gouge isn't
allowed to wander off and bite wrong into the piece.
- Hip hand twists the gouge in the appropriate direction.
- The whole body moves with the gouge when it is cutting.
- THIS IS HOW TO KEEP THE GOUGE FROM GOUGING.
Bowl Turning
- General comments
- For bowls, a deep fluted gouge is used. The deep flute exposes
sufficient bevel to remain safe inside the bowl.
- The outside of a bowl is like a large bead.
- The inside of a bowl is, well, like the inside of a bowl. It
poses special problems not seen in spindle turning. The bowl gouge
is the answer to these special problems of angle.
- Hollow forms, bowls or vessels whose opening is narrower than the
widest point inside, were not discussed much in this class. They
require special tools including scrapers, hooks and other fancy
replacements for the gouge.
- Steps in making a bowl (assume bowl blank in hand)
- Chuck on face plate or screw center.
- Rough off corners.
- Turn spigot.
- Flip bowl around and chuck spigot in ajustable-jaw chuck.
- Sink drill bit (hold drill bit in Jacob's chuck) in center to
desired depth. (This can be done by hand. It's actually a trick I
learned from Richard Raffin; it was not illustrated in this class
specifically, but it was alluded to.)
- Core out the inside of bowl. When the bottom of drilled hole is
reached, stop coring.
- Turn bowl around in press plate, adjustable-jaw extensions,
vacuum chuck, between centers, or other solution to clean up foot
(or turn it off completely as for a salad bowl).
- Notes on turning the bottom.
- Against the bottom outside of the bowl, place the flute against
the wood. Bring the gouge straight out and up the side of the bowl
until it reaches the tool bevel almost as if spindle turning.
- For bottom outside work, especially roughing, hold the handle
down low putting the gouge at around a 45° angle to the floor.
Hold against thigh.
- Notes on cleaning up the lip.
- The lip should be cleaned up early because coring weakens the
walls of the bowl destabilizing the lip. The flute faces left and
the gouge is pulled from right to left (from inside to outside),
finishing on the bevel.
- Notes on turning the inside.
- Clean the face of the bowl.
- Enter the bowl at the edge inside the rim. The gouge flute will
face right as is shown in this gouge cross-section here.
Only the part of the cutting edge indicated by the red, parallel
line here is used to make the cut.
- The gouge is pulled along to scoop out the inside little by
little. This is done by pulling the end of the handle held in the
right hand toward the body as illustrated here (notice too
the cross section reminding the gouge's orientation and direction
of travel). Any extent to which the body can anchor the gouge
handle and move along with it is good.
- As build-up around center occurs, flip gouge around with the
flute to the left and shear-scrape back to outside. Even if a hole
is predrilled (à la Raffin), a build up around it may occur.
Sharpening
- Grinder, 1700 rpm, 8" minimum, various jigs, but the best is a flat
plate in front with lots of room to move around. If the plate is too big,
it may interfere with sharpening gouges as they get shorter.
- Tomec® system is expensive (around $500), slow and ill-adapted to
woodturning. It is probably more useful for taking care of woodcarving
tools.
- Place grinder up high.
- Equip grinder with a light.
- Fingernail gouge grind is basically a straight line from tip to end of
bevel (on side of gouge); looks curved because of fluting in the body.
- Grinding action for gouge starts low on tip and moves up the surfacr of
the wheel as the gouge is rolled onto its side.
- The bevel must remain unifaceted across its entire surface no matter
what the tool.
- The angle to put into a skew is personal and depends on how the tool is
used.
Drying
Wood moisture content and stability is critical to bowl turning. A number of
aspects and solutions were discussed.
- Cut timber immediately upon felling because checks will open from the
outside (which dries much faster than the inside) in wedges into the wood.
- Cut in half and in quarters, eigths, etc. depending on bowl size.
Generally, the grain runs through the bowl from side to side rather than
running through the bowl's axis.
- Waxing is time-consuming.
- Steps in caring for moisture content
- Rough turn bowl to 3/4" up to 2" thick
depending on overall dimension (bigger bowls will need more
thickness for returning true).
- Envelop bowl in Saran Wrap®, poke weep holes into concave,
store upside down to avoid puddling moisture in bottom of inside.
Depending on climate, bowl will be dry in just a few weeks (the dry
West) to several months (the wet East and South).
Finishes
Finishes vary greatly. The following were the ones Clead discussed.
- Mixture of alcohol, oil and varnish.
- Danish oil.
- A compound named "Deft-oil" containing not only an oil that penetrates
the grain, but a polyurethane that will cure and then protect.
- Bowls are usually too big for friction wax (polish) which builds up too
unevenly in the time it takes to apply it.
| See pictures from this workshop.
|