Greetings Tobey, Joe, Orchid:
I have used various sizes of split mandrels in my Foredom
flexshaft for over 20 years, none of which were purchased, but made
from coat hanger wire, of the shanks of used-up grinding points,
etc. All of these have been more convenient and far cheaper than
anything offered by our supply companies, and is also good
concerning recycling (packratitis?).
Hanger wire is, on average, 3/32" thick, and is good in a pinch if
you have nothing else; cut to a working length of 2", it is best
slotted to a depth of 1/2" with a #0 jeweller’s saw (or a thin
cut-off wheel for the steel shanks), and then tempered/case
The depth of the slot should indicate a good sanding flap width,
with these considerations: that the sandpaper should extend
slightly over the mandrel tip, so that the tool tip doesn’t come
into contact with the workpiece (unless you want to sand & burnish
at the same time); and that the sandpaper is cut thin enough for
the smallest applications, but just above the size where the flap
will shred in use. Finer grades of emery paper are light-duty A-
or B-weight stock and should be backed by masking tape before use.
The slot should, of course, be just wide enough to grip the
sandpaper tightly when the tool is in use, but loose enough to
permit flap replacement. I recommend using the two-flap method,
where one end of each flap is folded over, then both hooked
together facing opposite each other, then inserted into tool; this
method eliminates the ‘skipping’ motion experienced using one flap
only, and also makes the paper last longer in use. It should be
noted that this tool produces excellent results when only the flap
tips are allowed to touch the workpiece, and then bringing the tool
closer in for heavier applications.
Unlike the steel shanks of old grinding points, hanger wire should
be tempered/hardened to a spring-quality blue to impart greater
durability. This is important concerning the two prongs of the
slot, in that they do not deform/bend/break off in use (creating
yet another interesting projectile to dig out of your forehead).
Lastly, round off & polish the slot end, so that if the tool does
come in contact with the workpiece, damage will be minimal.
This tool has served me well in fine wood carving as well as the
smithy, and I invite everyone to try it, and see if it lessens
production time, and (being less prone to scratching) improves
final product finish.
Daniel P. Buchanan firstname.lastname@example.org