Porter-Cable 504 Sander User Manual


 
12
Secure the work and maintain a firm grip on the sander.
Friction between the sanding belt and the work will tend to
move the work backward and the sander forward.
Always be sure that the switch is “OFF” before connecting
the tool to the power source.
1. Hold the sander off the work before starting the motor.
2. Lower the sander to the work, touching the rear part of the belt first. Level
the machine when moving it forward.
3. Guide the machine over the work in overlapping strokes. Allow the
sander to do the work.
4. Avoid applying excessive pressure. The weight of the machine is usually
sufficient for a fast smooth finish. A slight increase in pressure may speed
removal of material, but too much pressure will slow the motor and
decrease removal.
5. Work back and forth over a fairly wide area to obtain an even surface.
6. Do not let the tool tilt. The edge of the belt can make a deep cuts into the
surface.
7. Do not pause in any one spot during the sanding operation. The belt will
eat into the work and make the surface uneven.
8. Lift the tool from the work before turning the motor "OFF".
9. Always be sure that the motor has completely stopped before putting the
tool down.
FAST SANDING ON ROUGH WORK
To smooth a rough surface quickly,
use a coarse grit abrasive belt. With
the belt positioned diagonally across
the grain, move the tool in the
direction of the grain (Fig. 6).
Overlap the strokes and cover the
entire surface, working from both
sides of the board (angle left and then
angle right.) Smooth the surface by
guiding the sander back and forth
with the grain. Change the belt to a
medium grit and follow the same procedure.
Finish by thoroughly working the grain lengthwise. Change again to a fine grit
and repeat. Always finish sanding with the grain
.
Fig. 6
REMOVING OLD PAINT AND VARNISH
Read and follow “ADDITIONAL SAFETY RULES FOR PAINT
REMOVAL” section of this manual.
This sander is an excellent tool for removing old paint and varnish from flat
surfaces. However, two problems are common: 1) sanding material that loads
the abrasive and, 2) friction heat caused by working too long in one place. To
overcome the loading problem, use a coarse grit open coat abrasive belt and a
single stroke action. Overheating can be avoided by using a fairly quick stroke
and moving to another area quickly. A piece of felt about 1/4" thick can be
inserted under the shoe for fast spot sanding and for working on stubborn areas
of paint and varnish.