3
Blank Preparation
1. Cut the blanks about 1/8” longer than the Brass Tubes to
allow for blowout or hole elongation. (The Lower Tube is the
longer of the two.) Maintain grain orientation of the two blanks
for turning by drawing a line lengthwise across the cut line.
2. Drill the blanks with a 10mm drill bit at a speed of about
750 RPM.
3. Scuff the Brass Tubes with 220 grit sandpaper to remove
oxidation and roughen the Tubes for better adhesion.
4. Prepare to glue with medium cyanoacrylate (CA) glue or
two-part fast-drying epoxy.
5. Working on one at a time, apply the glue to the outside of the
Brass Tubes, with a liberal amount around the ends that will
be inserted first. Do not apply glue to the inside of the blank,
as this will cause the glue to get inside the Brass Tubes and
ruin the tube.
6. Insert each tube with a twisting motion into the blank until
the tube is equidistant between both ends of the blank. Wipe
off any excess glue on the ends of the blank. Allow the
glue to cure.
7. Using a barrel trimmer or a disk or belt sander, trim the ends
of the blanks until you can just see the bright brass ends of the
tubes. The faces of the ends must be perpendicular to the
Brass Tubes and parallel with each other. It is imperative that
the length of the trimmed blanks match the original length of
the Brass Tubes and that the insides of the Brass Tubes are
clean and free of any glue.
8. Use a permanent marker to make marks inside the Brass
Tubes that line up with the grain-alignment lines you drew
on the outside of the blanks. This will help you maintain
grain continuity after the blanks have been turned.
Fig. 1.
Turning the Blank
1. Assemble the blanks on the mandrel with the bushings.
Mandrel Setup. Keep the grain orientation of the blanks in
line when mounting. Each bushing has a step that is designed
to be inserted into the Brass Tubes for stability while turning,
as the inner diameter of the tubes is larger than the mandrel.
2. Tighten the tailstock and then tighten the mandrel nut that
holds the blanks. Do not over-tighten the tailstock or mandrel
nut as this may cause the mandrel to flex, causing the blanks
to go out of round.
3. Turn the blanks to the desired shape, making sure that the
surfaces next to the bushings are turned to the same diameter
as the bushings.
4. After turning, sand the surfaces in progressive steps of 240,
320, 400 and 600 grit. If a higher finish is desired, Micro-Mesh
abrasives may be used.
5. Apply the finish of choice and polish.
6. Remove the blanks from the mandrel, taking care to maintain
blank orientation and grain alignment.
Mandrel Setup
Fig. 1
Place a small piece of painter’s tape
around the blanks toward the center onto which you can
transfer the grain-alignment marks from inside the tubes.
Upper Tube
Lower Tube
Nut
11.7mm
13.4 mm
14.5mm
12.1mm
Mandrel
Cuban Pen Bushings
