Bosch 1700 Operating/Safety Instructions Manual page 10

BM 1609929C33 10/03 10/28/03
SELECTING GRINDING WHEELS
Before using a grinding
WARNING
!
wheel, be certain that its
maximum safe operating speed is not
exceeded by the nameplate speed of the
grinder. Do not exceed the recommended
wheel diameter.
DISC GRINDING WHEELS
Grinding wheels should be carefully selected
in order to use the grinder most efficiently.
Wheels vary in type of abrasive, bond,
hardness, grit size and structure. The correct
type of wheel to use is determined by the
job. Use disc grinding wheels for fast
grinding of structural steel, heavy weld
beads, steel casting, stainless steel and
other ferrous metals.
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
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
WARNING
!
flat or the back edge of the
disc comes in contact with the work, a
violent thrust to the side may result.
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
2:49 PM Page 10
Grinding Operations
GRINDING TIPS
Efficient grinding is achieved by controlling
the pressure and keeping the angle between
wheel and workpiece at 10° to 15°. If the
wheel is flat, the tool is difficult to control. If
the angle is too steep, the pressure is
concentrated on a small area causing
burning to the work surface.
WARNING
!
grinding action and put dangerous stresses
on the wheel.
When grinding with a new wheel be certain
to grind while pulling tool backwards until
wheel becomes rounded on its edge. New
wheels have sharp corners which tend to
"bite" or cut into workpiece when pushing
forward.
Sanding Operations
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.
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.
-10-
Excessive or sudden pres-
sure on the wheel will slow
GRIT
Coarse
16-24-30
Medium
36-50-80
Fine
100-120
Very Fine
150-180