214 Agricultural Mechanics and Technology Systems
Copyright Goodheart-Willcox Co., Inc.
other types of sanders. A belt sander is very effi cient for quickly removing
considerable amounts of stock from the face of a piece of wood. Often a belt
sander is the fi rst step in smoothing a surface. A random orbital sander can
then be used to smooth out the surface (and remove the striations, or grooves,
created by the belt sander) before fi nishing.
When using a belt sander to smooth a surface, begin by turning on the
sander and allowing the motor to achieve full speed. Next, using two hands
(one on the trigger handle and the other on the forward handle for stability),
ease the sander to the surface with a slight forward motion. The rear roller
should contact the wood fi rst, followed by the rest of the sanding face
pressing onto the wood with a slight rocking motion.
Belt sanders have a substantial amount of torque, which causes the belt
to tend to grab the wood and drive the sander forward. Work the sander with
the grain of the wood as much as possible, and do not allow it to stay in one
place. Remember that a belt sander removes material quickly, so stop and
check the progress frequently. It is much better to have patience and allow the
weight of the sander to do the work rather than pushing down too hard and
risking damage to the work material that needs to be repaired later.
Before changing the belt on a belt sander, read the manufacturer’s
instructions. Typically, a belt sander has a lever on one side that releases the
tension between the front and back rollers. Once the tension is released, slide
the sanding belt off of the rollers. To install a new belt, center a new belt onto
the rollers, close the lever, and plug in the sander. With the sander running,
use small adjustments to the tracking control knob to align the belt correctly
on both rollers. As a new belt wears in, it will stretch and require tracking
adjustments to keep it aligned on the roller drums.
Sheet Sanders and Random Orbital Sanders
Sheet sanders are designed to work with rectangular, partial sheets of
standard sandpaper. Random orbital sanders, on the other hand, require
round disks, typically attached to the sander base with either adhesive or
hook-and-loop fasteners. See Figure 8-49A and B. The ability to use standard
sandpaper is a major advantage for sheet sanders, since sheets of sandpaper
are readily available at most hardware stores or home improvement centers.
The sheets are cut into halves or quarters and are then securely clamped
C
Levent Konuk/Shutterstock.com
Figure 8-49. Select the appropriate type of hand sander for the task and the material being finished. A—Random orbital
sander. B—Sheet sander. C—Detail sander.
A
VladaKela/Shutterstock.com
B
Alexander Ishchenko/Shutterstock.com