Sanding Operations - Bosch GWS18V-45 Operating/Safety Instructions Manual

2610041372 09-15 GWS18V-45.qxp_GWS 9/18/15 10:00 AM Page 14
SELECTING SANDING DISC
Sanding discs are made of extremely hard
and sharp aluminum oxide grits, phenol-resin
bonded to a sturdy fiber backing for fast
heavy-duty service and long life. The discs
vary as to size and spacing of the abrasive
grits. OPEN COAT (type H) — used for soft
materials and on paint or varnish. CLOSED
COAT (type K) —used for metal, hardwood,
stone, marble and other materials.
Sanding discs range in grit from 16 (very
coarse) to 180 (very fine). To obtain best
results, select sanding discs carefully. Many
jobs require the use of several grit sizes and
at times both "open coat and closed coat"
discs are required to get the job done faster.
See chart for application examples.
Operation: Refinishing painted wood or metal surfaces.
REMARKS
To remove paint and to smooth
surface irregularities.
To smooth
the rough sanding.
To remove scratches left by
previous discs.
To smooth surfaces for painting,
polishing or waxing.
SANDING TIPS
For best results, tilt the Disc Sander at a 10° to
15° angle while sanding so that only about 1"
of the surface around the edge of the disc
contacts the work.
If the disc (accessory) is held
flat or the back edge of the
WARNING
disc comes in contact with the work, a violent
thrust to the side may result.

Sanding Operations

If sander is tilted too much, sanding action will
be too great and a rough cut surface or
gouging and snagging will result.
Guide the Disc Sander with crosswise strokes.
Be careful not to hold the sander in one spot
too long. Do not use a circular motion, as this
makes swirl marks. Test before use on scrap stock.
Do not force or apply pressure when sanding.
Use only the weight of the tool for pressure.
Excess pressure actually slows the tool down.
If faster stock removal is desired, change to a
coarser grit disc.
Remove gummy paint from metal with an
"open coat" disc. Sand until sparks start to
appear, then stop and change to a "closed
coat" disc to remove any remaining paint.
When sanding wood the direction of the disc
GRIT
motion at the contact point should parallel the
Coarse
grain as much as possible. The rapid cut of
16-24-30
discs and the swirl type scratch pattern they
Medium
occasionally create generally prohibit their use
36-50-80
for producing the final finish.
Fine
Scratches and circular marks are usually the
100-120
result of using too coarse a grit. When
Very Fine
changing to a finer grit, move across the sand -
150-180
ing lines that were made by a previous coarser
disc.
When sanding automobiles or appliances,
wipe the metal clean with a non-flammable
solvent or commercial cleaner to remove all
wax and grease. By doing this first, the
sanding discs will sand better and last longer.
For heavy duty work, use a coarse grit disc
first. Follow-up with a medium grit to remove
scratches. To produce smooth finish, use fine
grit disc.
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SANDING WOOD
SANDING METAL