23
A
brasive Selection Guide
Grit Common Application
24........Abrasive planing, surfaci ng rough-sawn boards, maximum stock r emoval, gl ue r em ov al.
36........Abrasive pl aning, surf acing rough-sawn boards, maximum stock r em ov al, glue remov al.
50........Surfacing and dimensioning boards, trueing warped boar ds
60........Surfacing and dimensioning boards, trueing warped boar ds.
80........Light dimensioni ng, remov al of planer rippl es.
100......Light surfacing, removal of pl aner ripp les.
120......Light surfacing, mi nimal stock removal.
150......Fi nish sanding, minimal stock r emoval.
180......Fi nish sanding only, not f or stock r em ov al.
220 ..... Finish sanding only, not f or stock r em ov al.
Abrasives
The abrasive material you choose will have a
substantial effect on the performance of your
sander. Vari ati ons in paper ty pe, weight , c oati ng
and durability all contribute to achieving your
desired fini sh.
JET Abrasives are available in Ready-To-
WrapTM pre-cut lengths or in the convenient
Ready-T o-Cut pre-marked box. Your JET dealer
can recommend the best choice for your
application.
Selecting Drum Abrasives
It is important to select the proper grit of
abrasive f or the t y pe 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 am ount of stock to be r em ov ed.
Then progressively work toward finer grits. The
chart (Fi gure 29) sho ws the general u ses f or t he
various grits. JET offers abrasives in the ten
different grits shown – consult the stock
num bers on page 28 to order.
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 progres si ng through a sanding s equenc e.
For fine work, such as furniture, try not to skip
any grit grades duri ng the sanding proc ess.
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 v ary
by type of wood. Oak, for example, is
susceptible to burnishing because of its open
pores.
Cleaning Abrasive Strips
Regular l y clean t he abrasive str ips on the dr ums
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, build-ups resulting from burns
can also be removed with Plexiglas held on
edge ov er 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
mi nutes to 1 hour , t hen usi ng a br ush to r em ov e
any build-up. Dry the abrasive strips completely
before using. Any used solvents should be
discarded in compliance with environmental
regulations.
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, rem ov e the
strip and use what was the trailing end as the
starting end on the left (outboard) side of the
drum. Rev ersing the stri p will provi de a fresh set
of cutt ing edges on the abrasive.
Figur e 29