Powermatic 4224 - Manual (Page 15)

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10. Stop the lathe, remove workpiece and
attach face plate or chuck (see "Mounting
Stock" above).
11. Finish turning the outside of bowl with
1/2" or 3/8" bowl gouge. Leave additional
material at base of bowl for support while
turning interior. This will be removed later.
TO SHAPE INTERIOR OF BOWL:
1. Stop lathe and move tailstock away.
Remove center from tailstock to prevent
bumping it with elbow.
2. Adjust tool support in front of the bowl
just below centerline, at a right angle to the
lathe ways.
3. Rotate workpiece by hand to check
clearance.
4. Face off top of bowl by making a light
shearing cut across the top of workpiece, from rim to center.
5. Place 1/2" bowl gouge on toolrest at center of the workpiece with the flute facing top of bowl. The tool handle
should be level and pointed toward four o'clock, as shown in Figure 11.
6.
Use left hand to control cutting edge of
gouge, while right hand swings tool handle
around toward your body (see Figure 11).
The flute should start out facing top of
workpiece, and rotate upward as it moves
deeper into the bowl to maintain a clean
even curve.
As tool goes deeper into bowl,
progressively work out toward rim. It may
be necessary to turn the toolrest into the
piece as you get deeper into the bowl.
(NOTE: Try to make one, very light
continuous movement from the rim to the
bottom of the bowl to ensure a clean,
sweeping curve through the piece. Should
there be a few small ridges left, a light cut
with a large domed scraper can even out
the surface.)
7. Develop wall thickness at the rim and maintain it as you work deeper into the bowl (Once the piece is thin
toward the bottom, you cannot make it thinner at the rim). When the interior is finished, move tool support to exterior
to re-define bottom of bowl. (General rule of thumb: the base should be approximately 1/3 the overall diameter of the
bowl).
8.
Work the tight area around faceplate or chuck with 1/4" bowl gouge.
9. Begin the separation with a parting tool, but do not cut all the way through yet.
SANDING AND FINISHING:
1. Remove the toolrest and adjust lathe speed to approximately 500 RPM. High speed can build friction while
sanding and cause heat check in some woods.
2. Begin with fine sandpaper (120 grit) and progress through each grit, using only light pressure. Coarser
sandpaper tends to leave deep scratches that are hard to eliminate. Use power-sanding techniques to avoid
concentric sanding marks around your finished piece. Avoid rounding over the rim and foot with sandpaper; try to
keep details crisp. Finish sanding with 220 grit.
3. Remove sanding dust with tack rags or compressed air and, with lathe turned off, apply first coat of finish. Let
stand for several minutes, wipe off excess. Allow to dry before sanding again with 320 or 400 grit sandpaper.
4. Turn lathe back on and continue the separation cut almost all the way through the base. Stop at about 3" and
use a small fine tooth saw to separate the bowl from the waste.
5.
Apply second finish coat and allow to dry before buffing.