Datasheet

Small scratches
showed in this walnut
table
finished with an
oil/varnish
mix,
so
we rubbed
it with
an abrasive
pad,
using dark
brown wax from
Briwax.
(ltem
number
85G28
in
the Woodcraft
catafog,
priced
at
$12.50;
call8OOl225-1153
to
order.)
Sanding lacquer
with fine weUdry sandpaper
and no lubricant
turns
the top layer
of
finish
into a white,
powdery
dust.
Change
paper
often to avoid scratches from
corning. When
you're
done
with this
step, clean the surface with
a
rag
or
a blast of air.
muchhigherthan
semigloss. With
oils and
oiUvarnish mixes,
you're
limited
to satin.
Sornetirnes
.itts
sfunple
Let's
start
with the simplest
form of rub-
bing
out: applying a coat
of
paste
wax to
an
oiVvarnish mix.
Once the finish
has
cured,
use a white nonwoven
abrasive
pad
to wipe
on wax that contains
both
soft beeswax
and
the harder carnauba
wax,
as shown in Photo
D.
When
you're
finishing
light-colored
wood, try
Trewax
Indian
Sand. You
can buy a
one-pound
container at
www.wellspent.org
for
$10.28,
plus
$7.83
for
shipping.
As
you
rub,
you
round
over any
dust
nibs in
the finish,
giving
the
surface a
smooth
feel. You
run little risk
of cutting
through the finish
as
you give
the sur-
face a
soft, satin
glow.
A film
finish-varnish,
lacquer,
or
shellac-usually
contains
more flaws
than an
oiVvarnish mix.
The likely
cul-
prits
include
dust nibs,
brush marks,
bubbles,
drag marks,
and runs.
When
the
problems
are minimal,
rub-
bing out
can be as
easy as the
process
just
described.
Doing
this to a film finish
inffoduces
microscopic
scratches to the
surface
that create
a satin
sheen. Open
pores,
raised
areas, and
other flaws
remain,
but the satin
sheen makes
them
less
obvious. You
ian substitute
mintiral
spirits,
soap, or any
other lubricant
in
place
of the wax,
but it's nice
to correct
flaws
and apply wax
at the
same time.
l}Iore flaws?
l}tore
steps
Now let's
tackle
a thicker
finish with a
few
more
flaws. The
most
common
flaws-especially
with varnish,
which
dries
quite
slowly-are
dust nibs
in the
80
surface.
Use the blade
from a utility
knife to
eliminate most
of them after
each coat dries. Hold
the blade
between
your
thumb
and forefnger,
nearly
verti-
cal, and
gently
scrape the surface
with a
pulling
motion. Be
very
gentle
and avoid
putting
any blade marks in
the finish.
You can
sand out these nibs,
but the
blade method lets
you
work faster
and
with less
effort on flat
surfaces. Curved
or decorative areas
require sanding.
Scraping
also eliminates
the risk of
sanding through the
finish
pt
the
edges
of flat surfaces.
Finishes
iend to
pull
away from
any edge
and flow toward
the
center, leaving
the coating
significantly
thinner
along the
edged and making
sand-throughs more
likely.
Spraying a
finish
can
compensate for
this by build-
ing up the
edges,
but it's difficult
to
build a smooth, feathered
edge when
applying
a brushed or wiped
finish.
After
scraping
you
still need to sand
to
get
a level surface
and eliminate
any
other
flaws.
Speed up the
process
by
sanding the finish
level midway
through
the application
of finish
coats.
Silicon carbide
paper
wrapped onto a
block covered with felt,
cork, or rubber
works best for
leveling,
as shown
in
Photo
E. If
you
want
to sand dry,
stearat-
ed silicon
carbide
paper
(usually
gray)
is
generally
a
good
choice.
Stearated
paper
contains a soaplike material
that keeps
the
paper
from clogging.
However,
you're
better off
using
non-
stearated weVdry
600-grit
paper
(which
is usually
black) with water-based
finish
When
you
don't
have
much finish
to
work with,
it's all too
easy to rub through
it
and expose the bare wood,
as shown
here
on a handheld mirror.
@
evnnoRATrvE
AND
REAclvE
FINISHES
Each new coat
of an
evaporative finish,
such as lacquer
and shellac, fuses
into the
previous
one, so rubbing is
simple. Reactive finishes,
such as varnish,
dry
in
layers;
rubbing
through
one layer into
another
can create
unattractive, irregular lines.
Coats
Coats of
reactive