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, 50 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
12.4 Abrasive selection guide
Grit
Common Application
24
Abrasive planing, surfacing rough-sawn boards, maximum stock removal, glue removal.
36
Abrasive planing, surfacing rough-sawn boards, maximum stock removal, glue removal.
50
Surfacing and dimensioning boards, truing warped boards
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.
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.
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.
Table 2
19
Always wear eye protection while