19
belt. Turn take‐up screws on both sides until
equal tension is obtained.
12.
To check tension, turn on conveyor full speed
and place both hands on conveyor. If conveyor
belt can be stopped, continue tensioning until
conveyor belt cannot be stopped by both hands
on the belt while conveyor is operating at full
speed.
13.
Make sure conveyor belt runs smoothly inside
tracker slot and that the magnet is holding the
tracker in position.
14.
Continue to watch tracking of conveyor and
adjust only if necessary, making sure to keep
equal tension on conveyor belt at all times and
not allowing conveyor belt to buckle under
conveyor table.
12.0
Abrasives
The abrasive material you choose will have a
substantial effect on the performance of your sander.
Variations in paper type, weight, coating and
durability all contribute to achieving your desired
finish.
12.1
Selecting drum abrasives
It is important to select the proper grit of abrasive for
the type of sanding being performed to achieve
maximum results. As with any sanding operation, first
begin sanding with a coarser grit, depending upon the
roughness of the stock or the amount of stock to be
removed. Then progressively work toward finer grits.
The chart below shows the general uses for the
various grits.
The amount of stock to be removed is a major
consideration when choosing the grit grade with
which to begin. Grits 24, 36, 40 and 60 are primarily
designed for stock removal. Grits 24 and 36 will
remove the most material in one pass, whether you
are doing abrasive planing, cleaning up glued panels,
or flattening stock. Grits from 100 through 220 are
primarily finishing grits designed to remove the
scratch pattern from the previous grit used. For best
results, never skip more than one grit grade when
progressing through a sanding sequence.
For fine work, such as furniture, try not to skip any
grit grades during the sanding process.
In general, premium quality abrasives will produce a
better finish with a less noticeable scratch pattern.
Note:
Grits that are too fine can sometimes burnish
the wood and leave a glossy surface which will not
accept stains evenly. This will vary by type of wood.
Oak, for example, is susceptible to burnishing
because of its open pores.
12.2
Cleaning abrasive strips
Regularly clean the abrasive strip on the drum with
commercially available cleaning sticks, following the
manufacturer’s directions. When cleaning, also brush
the stick crumbs from the drum while it is still
rotating.
In some cases, heavy loaded areas can be removed
with Plexiglas held on edge over the rotating drum.
Always wear eye protection while
performing sandpaper cleaning, and take all
precautions to avoid any contact of hands or
clothing with the rotating drum.
Cloth‐backed abrasives can be cleaned by soaking in
paint thinner or mineral spirits for 20 minutes to one
hour, then using a brush to remove any build‐up. Dry
the abrasive strips completely before using. Any used
solvents should be discarded in compliance with
environmental regulations.
12.3
Increasing abrasive life
Abrasive life can be increased not only by cleaning,
but by removing the abrasive strip from the drum and
reversing it. To do this, remove the strip and use what
was the trailing end as the starting end on the left
(outboard) side of the drum. Reversing the strip will
provide a fresh set of cutting edges on the abrasive.
12.4
Abrasive selection guide
Grit
Common Application
24, 36
Abrasive planing, surfacing rough‐sawn
boards, maximum stock removal, glue
removal.
40, 60
Surfacing and dimensioning boards, truing
warped boards
80
Light dimensioning, removal of planer ripples.
100
Light surfacing.
120
Light surfacing, minimal stock removal.
150
Finish sanding, minimal stock removal.
180
Finish sanding only, not for stock removal.
220
Finish sanding only, not for stock removal.
Table 2
