This is how I make my shaving brushes. Please note, this is NOT the only way,but the way I do it. There are all sorts of turning methods, this just happens
to work for me.
First I have a sample board of pre-drilled holes from spade & forster bits.
Some holes have varying depth of cuts. I use this for a quick easy guide.
The knots are measured in mm, this is taken from the base of the plug
and is an approximate size. I use a drill press to drill all my holes. You can
also bore your hole exactly on the lathe by turning the hole. But I never
make just one shaving brush. I make them in batches, so it is quicker for
me to use the drill press.
After I select the appropriate drill bit, I mark the bit for the depth of cut.
I then drill about an 1/8 deeper. This is so I can square the blank on the lathe
and still have the correct depth after squaring. While the blank is still in my drill vise,
I change bits to a #7 drill bit and drill my center hole for taping, as I use a threaded
stopper mandrel for turning. The tap is 1/4 x 20 tpi, standard for the stopper
mandrel I use.
This is my hole jig. I have forster holes on the top and spade holes on the bottom.
All holes drilled & tapped, spray some WD40 on your tap, this make tapping
run a little smoother. Test your knots for fit of hole and depth.
This is a large piece of buffalo horn about 3" long. This is going to make a
large brush with a 28mm knot. I use a Beale chuck to hold my mandrel and
butt the tail stock up with a waste blank for most of the turning.
This piece of buckeye burl is pretty short and still makes for a nice brush handle
using a 20mm knot. This could be a typical bottle stopper blank.
All turned, ready for sanding and buffing.
A piece of tulip wood all shaped, tail stock removed to square end, then make
a few passes with my skew to smooth it out. Then sand and several coats of CA.
Make sure when you mount your mandrel in the chuck to leave room for your
tools to cut the top and room for your fingers to sand the top.
All handles turned, finished and buffed. Ready to set the knots.
I use 30 minute epoxy to set the knots. Be generous with it. These brushes
get a lot of abuse, from pulling and shaking by their owners! Make one last
test fit prior to setting the knot.
All finished. Remember it is just like tuning a bottle stopper only you set
the Badger hair knot instead of the cork.