|
Before you do anything ...
(before you even think about picking up your sander)
you need to do some PREPARATION
- Measure
and write down your square footage (this will help you
estimate your abrasive needs and the number of gallons of
finish you'll need).
- Take a
'before' photo of all floors.
- Remove
all carpeting, tack strip, carpet pad, and carpet-pad
staples.
-
Complete any patching or repairs.
- Secure
any loose boards by top-nailing them in place.
-
Counter-sink or remove all protruding nails or staples.
To ensure that you've found every nail, turn over a snow
shovel and drag it across the floor -- it will catch on
any you missed. It is crucial that all nails be removed
because sanding over exposed metal can cause a spark
hazard and ignite the airborne sanding dust. It can also
tear a hole in the paper, which will ruin the drum if it
continues to run its bare rubber at full speed on the
floor.
- Take
down all window treatments and any art you have on the
walls.
-
Temporarily raise any low-hanging light fixtures.
- Remove
the quarter-round molding by prying it off with a wonder
bar, being careful not to gouge the floor. Number the
pieces as you remove them to make re-installation
easier.
- Remove
doors that swing into the room.
- Stop up
the return ducts with an old towel to keep sanding dust
from circulating to the rest of the house.
- Sweep
the floor.
NOW, you can pick up your
rental sanders and get on with the job.
THE
SANDING PROCESS
Now that the floor is empty,
take a good honest look at it and assess its condition. How old is the
floor? When was it last sanded? Look at the amount and type of finish
left on the floor -- does it look like it was stained, i.e. darkened with
a pigment? Is there any visible finish coat left? Does it feel greasy
as though it were once waxed? Note any water stains. Check for scratches
and swirl marks left from previous sandings. Finally, run your hand across
the floor and feel for unevenness from board to board. All the flaws that
you just listed must be sanded down completely in order to get to the
good wood that is underneath the top layer of scarred wood. In other words,
you are going to be removing a serious layer of lumber from your floor.
Unfortunately, most people are afraid to do this. They're worried about
taking off too much wood and ruining their floor. Stop worrying. That
floor is 3/4" thick. It was designed to live through four or five
sandings in its lifetime - designed to have 1/32nd" or 1/16th"
of wood removed every 20 years or so. And if you really want your floor
to look like new, you have to willing to do just that. The most common
mistake we see in floors done by do-it-yourselfers is timid sanding; a
floor that still looks dingy because it wasn't sanded aggressively enough.
So, the more honest your assessment of the condition of your floor, the
more willing you will be to actually remove all the damage and truly renew
that floor.
Unfortunately, wood is hard, as is nearly
every finish used to coat wood. This means that sanding is a
slow, rather arduous process because you are trying to remove both wood
AND finish. Many customers come in, assuring us of the
pristine condition of their floor, convinced that renting a sander is
like renting a Rug Doctor. What those folks don't realize is that sanding
is a multi-stage process. You never sand a floor just once (not even a
newly laid floor can be sanded in one pass): you will need to make three,
four, or possibly five passes over that floor, each with a successively
finer grade or 'grit' of sandpaper. The early passes over the floor (at
24 grit and, if necessary, 16 grit) should get the floor flat and remove
most of the old finish. The more uneven the floor and the thicker the
finish, the lower the starting grit. After you have finished this stage
you will be able to see the wood grain very clearly, but there will be
very visible scratches left from the sander. The middle stage of sanding
occurs at 36 grit. The job of this abrasive level is to remove all remaining
finish from the floor. The next step is 60 grit: this abrasive cannot
remove finish, but it can erase the scratches made by the 36 grit paper.
The final pass is at 80 grit, whose job is to remove the scratches made
by the 60 grit pass and leave the floor completely smooth.
Floor sanding is done with
two machines. The main machine is the drum sander and it is used on the
main body of the floor. This sander is operated from a standing position.
But the drum sander cannot get very close to the walls, so to do the perimeter
of the room you need to switch over to the edger, a 7"diameter spinning
abrasive disc that is operated from a kneeling or bent-over position.
It's used for sanding around the edges of a room or in areas that are too
shallow to use the drum (hallways where the floorboards run across the
width of the hall must be done entirely with the edger). Even though these
two machines differ greatly in size, their aggressive power is well matched;
both remove the same depth of wood when using the same grit. However,
they both sand in very different ways and each machine requires that you
use a distinct sanding pattern. Before we explain how to operate the machine,
you need to know the patterns that each machine will follow.
SANDING
PATTERN FOR THE DRUM SANDER
The drum sander may look
like a cross between a vacuum and a lawn mower; you can't move it across
the floor in a vacuuming or mowing pattern. At any given frozen second
in time drum sanders are designed to cut a divot into the wood of your
floor that is 8" wide by ½" long. As long as the drum continues to move
across your floor, that cutting area leaves a nice, even swath of smooth
floor. But if you stop, even for a moment, the drum will leave a deep
trench called a 'stop mark' on the floor surface. This means that a drum
sander is only efficient when it is sanding while moving in a straight
line forward, or in a straight line backward. You cannot sand while you
are turning or changing direction. So, in order to make the least number
of turns, you sand one half of the room first, then turn around once,
and sand the other half.
|
With
Clark
EZ-8
brand
drum
sanders,
you will
always
begin on
the left
wall.
You must
always
make
sure
that the
machine
is IN
MOTION
before
you use
the
feathering
handle
to
gently
lower
the drum
to the
floor.
Just
before
you
reach
the
wall,
you will
lift the
drum off
the
floor
and as
you
begin
your
reverse
pass,
you will
lower it
gently
back to
the
floor as
you pull
the
machine
backward
over the
very
same
path
that you
just
covered
while
going
forward.
Once you
reach
your
starting
point,
you will
lift the
drum off
the
floor
completely,
move the
machine
over
four
inches,
and sand
up and
back in
the same
manner,
repeating
until
you
reach
the
right
hand
wall.
You will
then
turn the
machine
around,
position
yourself
at the
left
wall and
sand the
other
half of
the
room,
overlapping
the two
sections
slightly
to
ensure a
smooth
blend.
Do I
always
have to
sand
parallel
to the
grain?
Yes,
sanding
parallel
to the
grain
significantly
reduces
the
appearances
of
scratches.
There is
an
exception
to this
rule,
though.
Check
out 'The
Magical
Exception
of Cross
Cutting'
in the
next
section.
Why do I
have to
lift the
drum
before I
begin my
backward
pass?
If you
were to
leave
the drum
on the
floor as
you
transitioned
from
going
forward
to going
backward,
you
would
find a
little
stop
mark at
the
point
where
you
changed
direction.
In order
for the
machine
to
change
direction,
it has
to stop.
If it
stops,
it digs.
So, for
that
momentary
change
of
direction,
the
sanding
drum
must be
off the
floor.
Why do I
have to
do the
floor in
two
sections?
The main
reason
is that
you want
to leave
yourself
plenty
of room
to
maneuver
the
sander,
especially
when
you're
backing
up and
getting
into
position
for the
next
pass. It
you
accidentally
back
into a
wall,
both you
and the
sander
will
stop
dead and
leave a
deep
gouge in
the
floor.
Besides,
if you
start
with
your
back to
the
wall,
you
still
leave a
two foot
section
(the
area
that
you're
standing
on)
unsanded.
And you
will
quickly
learn
that
doing a
forward-backward
pass
over
anything
less
than
four
feet is
extremely
tedious.
Why sand
left to
right?
The
three
wheels
of the
sander
are
positioned
so that,
if you
move
left to
right,
all
three
wheels
are
travelling
level on
already-sanded
floor.
This
keeps
the
sanding
cut
level
across
the
entire
width of
the
drum. If
you move
right to
left,
the left
wheel is
running
on
unsanded
floor
and so
is
higher
than the
other
two
wheels,
causing
the
machine
to cut
more
aggressively
on the
right
side.
Do I do
all my
grits on
the drum
sander
first,
then
switch
to the
edger?
The drum
sander
and the
edger
are
always
used
ALTERNATELY.
If you
sand the
center
of your
floor
with 24,
then you
will
immediately
edge
that
room
with 20
grit.
Sweep
the
floor,
then
change
to a
36-grit
belt on
the drum
sander,
sand the
middle,
then
edge the
perimeter
at 36
grit and
so on.
It will
be
easier
to see
exactly
how much
finish
you have
left to
remove
with the
edger -
which
keeps
the
amount
of
edging
you have
to do to
a
minimum.
You'll
also get
a better
blend of
the
straight
scratch
from the
drum
machine
and the
curved
scratch
from the
edger if
you
alternate
them.
SANDING
PATTERN
FOR THE
EDGER
Edgers
run
clockwise,
so you
will
spend
less
time
fighting
the
machine
if you
sand the
room
clockwise.
Always
start
from the
field of
the
floor
and move
toward
the
floor so
that you
can be
sure to
blend
the area
sanded
with the
drum
sander
into the
area you
do with
the
edger.
Sand 1-2
feet at
a time,
always
keeping
the
edger
moving
back and
forth in
a
Z-pattern,
moving
closer
to the
wall
with
each
pass.
Make
sure to
overlap
and
blend
you new
section
with the
section
you just
completed.
We
strongly
urge you
to mark
up the
perimeter
of you
room
with
pencil
marks so
that
track
your
progress
around
the room
and
ensure
that you
have
sanded
everything.
Sometimes
it is
hard to
keep a
regular
pattern
(as you
do with
the
rectangular
drum
sander)
with a
circular
sander.
CHOOSING
ABRASIVE
As we
mentioned
before,
doing a
professional
job on
your
floor
will
probably
entail
four
sanding
passes
over
your
floor,
but you
do have
some
flexibility
in
choosing
the
abrasive
for your
first
pass.
The five
grits of
abrasive
available
for the
drum
sander
are 16,
24, 36,
60 and
80. The
grits
available
for the
edger
are 12.
16, 20.
36. 60,
and 80.
Most
floors
in the
Twin
Cities
were
built
prior to
1950 and
will
require
a
starting
grit of
at least
24. If
your
floor is
younger
and you
are
convinced
that you
do not
need to
begin
that
aggressively,
do this
test:
put a 36
grit
belt on
the
machine
and go
to the
worst
section
of your
floor.
Spend
5-6
minutes
and sand
a 7'x8'
area.
Now,
turn the
machine
off and
look at
that
sanded
section.
If you
can
honestly
say that
there is
no
finish
left on
that
floor
and that
you
cannot
feel the
board
edges
when you
run your
hand
across
the
wood,
then you
can
proceed
to sand
with 36,
proceeding
through
60 and
80. But
if there
is still
visible
finish
in the
test
area,
you are
better
off
doing a
fast
pass at
24 to
get the
bulk of
the
finish
off
before
you get
to 36
grit and
remove
every
last bit
of it.
Remember,
60 grit
and 80
grit are
not
designed
to
remove
finish -
all they
do is
smooth
out
scratch.
If you
have the
reverse
- a
severely
scarred,
uneven,
water-damaged
or
painted
floor,
then you
may want
to
consider
not only
starting
with a
coarse
grit,
but
sanding
at an
angle to
the
grain:
The
Magical
Exception
of
Cross-Cutting
This is
an
important
exception
to the
rule of
always
sanding
with the
grain of
the
wood. It
only
applies
during
the
rough
sand
stage,
but it
is a
very
efficient
way to
speed of
the
process
of
cleaning
and
leveling
an old
floor.
Because
of
wood's
natural
tendency
to shred
and
splinter
when it
is
sanded
off-grain,
the
sander
can
remove
more
wood
with the
same
amount
of
effort,
when
sanded
at an
angle.
The
angle
does not
need to
be
drastic
-
sanding
10-15°
off of
parallel.
The down
side of
using
this
procedure
is that,
after
you make
an
entire
pass at
an
angle,
you must
follow
it with
another
pass
parallel
to the
grain at
the same
grit.
So, if
you do a
24-grit
cross
cut
pass,
you
sanding
sequence
would be
24diagonal
->
24straight
-> 36 ->
60 ->
80.
Newly
installed
floors
can be
rough-sanded
with
36-grit
parallel
to the
grain.
The rule
to
remember
is that,
no
matter
what
grit you
choose
as your
starting
point,
you must
sand, in
order,
with
every
grit
that is
finer
that
your
starting
point.
So, if
you
start
with
16-grit,
you
cannot
jump to
36 grit;
you must
go 16 ->
24 -> 36
-> 60 ->
80 on
both
machines.
If you
start at
24-grit,
you
cannot
jump to
60; you
must go
24 -> 36
-> 60 ->
80 on
both
machines.
How will
I know
if I
have
chosen
the
right
grit to
begin?
If your
abrasive
fills
with old
finish
(called
'glazing'
or
'loading')
immediately
into an
initial
cut, you
need to
switch
to a
coarser
abrasive.
Otherwise,
as long
as the
abrasive
is
cleaning
the wood
as you
expect
it to,
continue
with it.
How will
I know
when to
change
the
abrasive?
Turn off
the
machine
periodically
(after
every
100sqft
on the
drum
sander,
after
every
corner
on the
edger
(|),
unplug
it and
look at
your
abrasive.
If it
feels
duller
is
clearly
full of
old
finish,
it
should
be
changed.
Belts on
the drum
sander
cut in
both
directions
-
turning
the belt
around
can
expose
fresh
mineral
and
extend
the life
of your
belt.
HOW TO
OPERATE
THE EZ-8
DRUM
SANDER
-
Install
a
sleeve
of
abrasive
over
the
sanding
drum,
center
as
best
you
can,
and
close
the
access
door.
Make
sure
the
dust
bag
is
tied
around
the
exhaust
pipe.
-
Connect
the
machine
to
an
appropriate
grounded
and
fused
circuit.
20
amp
circuits
(usually
found
in
kitchens
or
bathrooms)
are
best.
-
Roll
the
machine
to
your
starting
position
(usually
close
to a
wall,
parallel
to
the
floorboards,
halfway
up
the
floor).
-
Make
sure
that
the
sanding
drum
control
lever
is
in
the
'up'
position
and
that
the
sanding
drum
is
not
in
contact
with
the
floor.
Turn
the
selector
switch
to
the
start
(S)
position.
Once
started,
allow
switch
to
return
to
the
run
(R)
position.
-
Feather
cut-in
by
easing
the
sanding
drum
down
onto
the
surface
with
the
control
lever
while
the
sander
is
in
motion.
-
When
the
sanding
drum
is
fully
engaged
with
the
surface
release
control
lever
and
adjust
your
pace
for
adequate
stock
removal,
but
keep
your
pace
steady
at
all
times.
Keep
sander
in
motion
while
sanding
drum
is
engaged
with
the
surface
or
stop
marks
will
occur.
-
Move
the
machine
in
the
direction
of
the
grain
whenever
possible.
Sand
the
surface
at a
constant,
deliberate
pace.
-
Gradually
feather
cut-out
at
the
end
of
your
pass
by
easing
the
sanding
drum
up
with
the
control
lever.
Stagger
the
termination
points
for
a
better
blend
when
edging.
-
When
replacing
abrasive,
emptying
contents
of
dust
bag,
or
when
sanding
operation
completed,
press
selector
switch
to
off
(O)
position
and
immediately
disconnect
the
machine
from
power
supply.
-
Empty
dust
bag
whenever
it
is
1/3
full.
Never
leave
a
dust
bag
unattended
with
sanding
dust
in
it.
Sanding
dust
can
spontaneously
ignite
and
cause
a
fire
or
explosion.
Empty
dust
into
clean
plastic
bag,
seal
tightly,
and
store
away
from
buildings.
Never
include
stain-or
solvent-soaked
rags
in
the
bag
with
the
sanding
dust.
HOW
TO
OPERATE
THE
EDGER
-
Install
the
sandpaper:
Turn
the
machine
upside-down.
A
special
wrench
is
in
the
bracket
behind
the
motor.
Use
the
wrench
to
remove
the
screw
and
washer
from
center
of
sanding
pad.
Center
the
maroon
pad
and
sanding
disc
over
the
sanding
pad.
Put
the
washer
and
holding
screw
in
position
in
the
center
of
the
sanding
pad.
Using
the
wrench,
turn
the
screw
clockwise.
Make
sure
the
screw
is
tight.
-
Attach
the
dust
bag
over
the
end
of
the
exhaust
pipe.
-
Move
the
machine
to
the
location
of
your
work.
-
Connect
your
extension
cord
to
the
short
power
cord
on
the
machine.
-
Put
the
variable
speed
switch
in
the
'hi'
position.
NOTE:
High-speed
mode
is
for
rapid
removal
of
wood.
For
finish
cuts
and
custom
work,
use
the
low
speed
operation.
-
Connect
the
other
end
of
your
extension
cord
to
the
power
supply.
DANGER:
Always
unplug
the
machine
before
changing
abrasive.
Never
leave
the
machine
unattended
while
plugged
in.
-
Tilt
machine
back
so
that
sandpaper
disc
does
not
touch
the
floor.
-
Put
the
on/off
switch
in
the
'on'
position.
-
Keep
machine
moving
as
you
lower
sandpaper
disc
to
the
floor
surface.
Do
not
press
down
on
the
machine.
The
weight
of
the
machine
provides
enough
pressure
for
all
types
of
sanding.
-
Remove
the
dust
bag
and
empty
it
(into
a
safe
container
and
away
from
any
buildings
or
flame)
when
the
bag
is
1/3
full
or
when
the
efficiency
of
the
dust
control
system
decreases.
NOTE: Do
not
store or
rest the
machine
on the
sanding
disc
assembly.
It may
cause
the
rubber
pad to
become
warped
or cause
it to be
out of
balance.
CLEANING
UP AND
APPLYING
FINISH
After
you have
finished
using
both
sanding
machines,
your
floor
will be
clean
and
smooth,
but it
will
have
invisible
straight-line
scratches
in the
main
field of
the
floor
and
curved
pig-tail
scratch
around
the
perimeter
of the
room. To
blend
those
two
scratches
so that
they do
not
cause
your
finish
coat to
have a
'picture-frame'
effect,
you
should
give the
floor
one
final
polish.
This is
done
with a
buffer
or by
hand
using a
pole-sander.
No
matter
which
method
you
choose,
the
actual
smoothing
is done
with a
150 grit
sanding
screen -
a sharp
mesh
that
looks
like
window
screening,
and all
passes
are made
parallel
to the
grain.
This
final
step
makes a
big
difference
in the
quality
of your
finished
floor by
erasing
any last
traces
of edger
swirl
and
allowing
the
floor to
absorb
your
finish
uniformly.
After
you have
done
that
final
light
polishing,
you can
begin
the
cleaning
process:
-
The
floor,
baseboards
and
windowsills
should
be
thoroughly
vacuumed
with
a
soft-bristle
attachment.
Removing
dust
from
baseboards
and
windowsills
will
prevent
accidental
showers
of
sanding
dust
getting
knocked
onto
the
floor
while
you're
coating.
Take
a
shower,
or
at
least
shake
yourself
off
well
before
you
continue
-
this
will
keep
the
dust
from
your
hair
and
clothing
out
of
the
wet
finish.
-
Tack
the
floor
with
a
DRY,
no-lint
rag
or
towel.
Do
not
use
conventional
'sticky'
tack
rags
as
they
can
leave
a
residue
on
the
floor
that
could
prevent
your
finish
coat
from
bonding.
An
easy
way
to
tack
the
floor
is
to
wrap
your
towel
around
a
push
broom
and
walk
up
and
down
the
floor
with
it
until
the
towel
no
longer
picks
up
any
sand
or
dust.
-
Plan
the
steps
you
must
take
to
coat
your
floor
without
painting
yourself
into
a
corner.
-
Dampen
your
applicator
with
a
solvent
that
matches
the
finish
you
are
using
(water
for
waterborne
finishes;
paint
thinner
for
oil-modified
finishes)
and
scrape
it
with
a
paint
stick
to
loosen
any
loose
fibers.
-
Apply
a
generous
puddle
of
finish
directly
on
the
floor.
Get
your
pad
painter
thoroughly
soaked
with
finish
from
the
puddle,
press
it
out
so
that
it
is
no
longer
dripping,
and
cut
in
along
your
first
edge,
always
working
with
strokes
parallel
to
the
grain.
-
Apply
a
long
line
of
finish
directly
on
the
floor
along
the
line
you
just
cut
in.
Get
your
mop
applicator
thoroughly
wet,
then
press
out
excess.
Beginning
at
one
wall,
pull
you
applicator
along
your
puddle
parallel
to
the
grain,
which
will
spread
or
'snowplow'
your
finish
across
your
floor.
When
you
reach
the
opposite
wall,
stop
short
by a
foot,
wring
your
mop
edge
out
gently,
and
begin
your
next
pass.
It
helps
if
you
can
have
a
second
person
continuing
to
cut
in
along
the
wall
edge
as
you
proceed,
as
well
as
adding
more
finish
to
your
puddle
and
noticing
any
skips
or
puddles
that
can't
be
seen
from
the
coater's
viewpoint.
-
Coating
sequence,
drying
time
and
coverage
will
vary
according
to
the
type
of
finish
you
have
chosen.
Most
polyurethanes
will
require
a
light
sanding
between
coats
sometime
during
the
coating
sequence.
Every
time
you
do
this
inter-coat
abrasion,
more
dust
is
produced
and
you
must
re-vacuum
and
re-tack
the
floor
just
as
thoroughly
as
you
did
the
first
time.
Once
you
have
a
layer
of
finish
on
the
floor,
any
time
you
sand
and
tack
the
floor,
you
will
need
to
use
a
damp
tack
rag
-
just
dampen
your
rag
with
the
solvent
that
matches
your
finish
(water
for
waterbornes;
paint
thinner
for
oil-modified).
This
will
do a
much
better
job
of
removing
those
last
traces
of
grit
and
dust
that
can
leave
with
a
rough
and
unsatisfactory
finished
floor.
© Pete's
Hardwood
Floors.
All
products
cited
are
copyrights
of their
respective
owners.
Website
comments
should
be
directed
to
peteshardwoodfloors@gmail.com
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