Pipe
Sander Case Study
Sanding machine finishes the job
How
one company solved its finishing dilemma with a portable pipe
sander
By Tom Carroll
September
12, 2002
AAMS needed
a way to polish aluminum and stainless steel handrails in two
separate construction projects. To get the job done, they turned
to a dedicated tube and pipe sander, which allowed them to accomplish
the necessary finish in half the time manual polishing would have
taken.
AAMS Corporation,
a miscellaneous-metals fabricator in Taunton, Mass., recently
took on a large project for Olin College of Engineering, a new
institution of higher learning near Boston. The project called
for fabricating about 1,500 feet of 1-1/2-inch stainless steel
pipe for handrails and stairway railing at the college (see Figure
1a).
The challenge
for AAMS was not so much in the size of the project as in the
finish required. A polished look was specified for all components
of the job, which involved a large number of 90-degree corners.
At the same
time AAMS also was working on a complex project for a retail-residential
building at Uphams Corner in Boston. The company was constructing
400 ft. of railing for handicap entrance ramps. The ramp rails
were fabricated from 1-1/4-in. Schedule 40 aluminum pipe with
aluminum molding (see Figure 1b). After the pipe was welded and
ground, the railing also required a polished finish.
AAMS wanted
to be very careful with the rail polishing because both customers
required it for aesthetic purposes. The company previously had
relied on a 4-in. angle grinder for finishing. The angle grinder
had been used mainly to grind down welds, and AAMS was doubtful
that it could produce the highly polished finish necessary to
meet the customers' specifications. Also, when working with 90-degree
bends, operators found it difficult to move this type of grinder
into the tighter spaces.
It soon became
obvious that the finish produced by a conventional grinder would
not be acceptable. A swirl pattern rather than a polished finish
was the result from this type of grinding (see Figure 2). This
was caused by the circular rotation of the grinding disk moving
the abrasive against the grain of the pipe. The company could
have achieved a uniform grain by hand polishing with steel wool,
but the company considered that method too time-consuming, and
it required a great deal of manual effort.
This led
to a decision by AAMS to search for an alternative. The company
decided it needed a finishing machine specifically designed for
use on tube and pipe.
While scouring
the Internet to find a tool that would help them achieve the required
finishes, AAMS considered several pipe sanders. It chose the CS
Unitec pipe sander, model LBR 1506 VR. According to Brendan Pequita,
AAMS's layout specialist, the pipe sander was lightweight, making
it easy to use, and it was also affordable.
In addition,
it met another of the company's requirements by being portable
enough to be used both in the shop and in the field. The sanding
machine was suitable for 3/8- to 10-in. pipe, and the belt tightened
continuously for different pipe diameters.
AAMS continued
to use the 4-in. angle grinder to bring down the welds on both
projects, but to achieve the final finish, it put the pipe sander
to the test. The operator placed the sander over the pipe, which
fit into a contour on the machine, and then walked it along the
length of the pipe while an abrasive belt rotated around it. Because
the sanding belt moved around the circumference of the pipe, the
sanding was done in one direction, enabling it to meet the polishing
specifications.
The operators
went through several steps with the pipe sander to get the polish
that was needed. They began using it with coarser 36-grit abrasive
belts to remove gouges or imperfections in the milled pipe. Next
they went to a medium 80 grit, which smoothed out the pipe, removed
any marks left by the coarser grit, and produced a matte finish
in preparation for final polishing. The final polish was made
using a fine 120 grit, which gave the pipe the specified decorative
look.
AAMS estimates
that finishing the two jobs with the pipe sander took half the
time hand polishing would have taken. The tool proved to be adaptable
to every surface of the rails for both projects. It was easily
maneuvered around corners, fitting right into the 90-degree angles.
In addition, Pequita said, "Because the machine did all the work,
there was much less physical stress for the operators."
The pipe
sander not only helped AAMS to finish these two projects as prescribed
in a reasonable time frame, but it also gave this fabrication
company new capabilities that can help it expand its customer
base. Pequita predicted that "Now that we have the pipe sander,
we will be much more likely to take on other finishing work in
the future." In addition to polishing, pipe sanders can be used
for standard grinding and surface structuring (see Figure 3) and
cleaning of pipe.
Tom Carroll
is president of CS Unitec Inc.
22 Harbor Ave., Norwalk, CT 06850
phone: 800-700-5919
fax: 203-853-9921
e-mail: info@csunitec.com,
CS Unitec supplies specialty power tools for surface finishing
and metal fabricating.
Reprinted
with permission from the September 2002 issue of The FABRICATOR®,
copyright 2002 by The Croydon Group, Ltd., Rockford, Illinois
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