Stock Making index
Part 6 Shaping the forearm
Our first step in this part is to
clean up the stock from the grip area back to the butt plate. I start
with a flat Microplane and begin smoothing the flat areas, feeling for
high spots as I go. With a round Microplane, I clean up the areas next
to the thumbhole ridge, making a smooth continuous transition from the
ridge to the butt.
with an orbital sander, and manually with 80 grit paper, I carefully
remove the marks from the Microplane, being careful not to change the
contours I just worked so hard to achieve.
blanks are like a box of chocolates. You never know what you’re going
to get. As you get deeper into the carving, you can uncover some
fantastic grain and figure, or you can uncover unwanted knots and voids.
A fancy knot doesn’t necessarily bother me, as that is just the way
nature makes wood, but a knot that leaves a void has to be dealt with
cosmetically. A simple trick is to mix some sawdust from your wood with
a little yellow glue and use the mixture to fill the void. You can use
epoxy for larger voids, but this one is small enough for the yellow
the sawdust and glue to a consistency of Play Doh, more dust than glue.
Use a putty knife to force the mixture into your void. Don’t just skim
over it, pack it in tightly.
Let the repair dry for at least 30 minutes then sand it smooth. It will still be a knot, but the void will be gone.
next step is to taper the forearm. I like the look and feel of a
tapered forearm. I taper the blank from full width at the thumbhole to
about full width minus 1/2 inch at the front of the forearm, depending
of the diameter of the air tube. To mark the blank, I place a piece of 1
¼ inch Delrin, the diameter of the Marauder air tube, into the air tube
cut, and using a flush cutting trim saw and a precision thickness
gauge, I make two small cuts that can be seen when I turn the blank
upside down. The flush cutting trim saw has its teeth set in one
direction only, so it won’t damage my expensive thickness gauge.
made a fixture for tapering blanks from a piece of Melamine shelving,
using stove bolts and wing nuts for clamping. The bottom of the clamping
slots are relieved for the heads of the stove bolts to allow the
fixture to sit flat on the table saw. The smaller slot fits the square
of the stove bolt and keeps it from spinning while tightening the
clamps. I set the table saw fence to the width of the fixture so that
the saw blade is flush with its edge.
aligning the saw cut at the front of the blank, and the side of the
blank at the thumbhole, with the edge of the fixture, I get exactly the
taper I want.
angled hand hold on the fixture allows me to keep pressure against the
fence while feeding the blank through the blade. The saw blade is fully
raised for this cut, so care must be taken using this procedure.
Once one side is cut, I reverse the blank and taper the other side.
Using a sanding block and 80 grit paper, I remove the saw marks from the angle cuts.
now to the router table, I cut a ¾ radius on the bottom edges of the
forearm. This is accomplished by using a ¾ inch roundover bit and a
starting pin. The starter pin screws into the aluminum router plate. The
fence is not used for this operation. The blank rides on the ½ inch
bearing on the cutter, and the starter pin. Using a starting pin is the
only safe way to make this cut. Always feed the stock into the rotation
of the bit with the blank against the pin, and remember the rotation is
counter clockwise when the router is upside down. In other words, feed
the stock AWAY from you when on the LEFT side of the cutter, and TOWARDS
you when on the RIGHT side of the cutter.
the blank rides against the bearing of the cutter, I have to be
especially careful when I get to the holes for the manometer and the
mounting stud. I just leave the cut a little fat in those places, and
clean it up later.
Using the Microplanes and 80 grit paper, I clean up the areas around the manometer hole, and the trigger guard.
final cut on the forearm is made with a large thumbnail bit. I switch
to a router plate with a larger insert opening, and set the depth of the
cutter so that there is no “cuticle” on the cut. I then adjust the
fence to leave a small flat on the top of the blank.
I clean up the cut with a sanding block and 80 grit paper. We now have two shaped stocks ready for sanding and finishing.
In the next installment, we will complete the sanding, and finish the stocks with Tru Oil.
Part 7 - Sanding and Finishing