Festool RO 125 FEQ Plus Supplemental User's Manual - page 15
Supplemental Owner’s Manual
15
Choosing Hand Positions
While it may sound trivial on the face of it, how you hold
the sander plays a pivotal role in the optimal performance
of the sander. Balance, control, and comfort are the keys in
deciding what hand positions work best for you. It is recom-
mended to spend some time practicing and refining your
handhold positions to suit your needs. They will vary from
user to user, but the information below presents the most
common starting point for many users.
The basic handhold positions are one hand forward and one
hand aft, with the forward hand providing the majority of
the control over the sander. The rear hand provides slight
guidance and balance to the sander. A grip near the power
cord works best for this.
The forward hand provides the majority of the control and
a majority of the balance. This may be over the top of the
motor or in front of the motor, with the front of the motor
being slightly more preferred by most users.
These hand positions provide the greatest separation of your
hands from the front to rear of the sander. This separation
is what results in greater control of the sander and makes it
easier to avoid tilting the sanding pad against the sanding
surface.
When experimenting with different hand grips, use varying
sandpaper grits and both modes of the sander. The goal is
to hold the sander in such a way that balance and control
are achieved, which results in the smoothest motion of the
sander as you move it about the workpiece. Here are some
signs that your grip on the sander is not balanced:
►
Uneven resistance to movement: If the sander resists
more in one direction than the opposite direction, it is a
sign that you are slightly tilting the sander.
►
If you experience excessive jumping and jitter, it means
your grip is not balanced, you’re moving too fast, and you
are applying too much down force to the sander.
Working With Sanding Grits
Generally speaking, the sanding process begins with the
coarser grits and progresses up to the finer grits. However,
not all sanding tasks are the same. So choosing which grits
to use will vary depending on the task. The adage of pro-
gressing through the grits holds true for nearly all sanding,
but where to begin and where to end isn’t always clear.
While the coarsest grits provide rapid material removal and
leveling, it isn’t always desired to begin sanding with the
coarsest grit available. Avoid starting with too coarse of a
grit. For example, when working with pre-planed lumber,
there should be little need to use a coarser grit that 120
unless there is the need for joint-leveling. Even with joint-
leveling, only a slightly coarser grit may be called for, with
coarser grits reserved for joint leveling of wider panels.
Similarly, the highest grit chosen should be commensurate
with the type of material and surface finish desired. The grit
size should be consistent with the grain size of the material.
Very high grits should be used for achieving a high gloss
surface on paints, finishes, and plastics. However, because
the grain size of wood is much larger than man-made mate-
rials, the highest (unfinished) sanding grit should be much
more limited.
When sanding bare wood in preparation for applying most
surface-build finishes, a sanding grit of approximately 220
grit should be considered the maximum, or even slightly
lower for very high-build finishes. On the other hand, for
non-build finishes or when the bare wood is the final finish,
then higher grits may be called for. Using too high of a grit
will tend to burnish the wood. With some non-build finishes
or for bare wood, this is desired. However, for most surface-
build finishes, burnishing can hinder finish penetration of the
surface.
For colorants, and especially pigmented stains, the higher
the bare wood sanding grit, the less the colorant will pen-
etrate the wood. In some cases this can even lead to a loss
of grain definition in the final finish. However, this can also
be used to an advantage for controlling the intensity of a
colorant, by using a coarser grit for a darker intensity and a
higher grit for a lighter intensity.
The purpose of progressing through the grits from coarse
to fine is so that each successive grit is aggressive enough
to remove enough material to remove the scratches of the
previous grit, while only leaving smaller scratches itself.
This is most apparent in the coarser grits where the grit
scratches are deeper.