v>EPA
United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/S-95/018 September 1995
ENVIRONMENTAL
RESEARCH BRIEF
Pollution Prevention Assessment for a Manufacturer of
Outboard Motors
Richard J. Jendrucko*, Thomas N. Coleman*, and
Gwen P. Looby"
Abstract
The U.S. Environmental Protection Agency (EPA) has funded
a pilot project to assist small and medium-size manufacturers
who want to minimize their generation of waste but who lack
the expertise to do so. In an effort to assist these manufactur-
ers Waste Minimization Assessment Centers (WMACs) were
established at selected universities and procedures were
adapted from the EPA Waste Minimization Opportunity As-
sessment Manual (EPA/625/7-88/003, July 1988). That docu-
ment has been superseded by the Facility Pollution Prevention
Guide (EPA/600/R-92/088, May 1992). The WMAC team at
the University of Tennessee performed an assessment at a
plant that manufactures outboard motors for water craft. Three
basic subunits received from other manufacturing plants un-
dergo primarily painting and assembly operations in order to
produce the final product. The team's report, detailing findings
and recommendations, indicated that paint overspray waste
and spent clean-up solvent are generated in large quantities
and that significant cost savings could be achieved by installing
robotic paint application equipment.
This Research Brief was developed by the principal investiga-
tors and EPA's National Risk Management Research Labora-
tory, Cincinnati, OH, to announce key findings of an ongoing
research project that is fully documented in a separate report
of the same title available from University City Science Center.
Introduction
The amount of waste generated by industrial plants has be-
come an increasingly costly problem for manufacturers and an
additional stress on the environment. One solution to the
* University of Tennessee, Department of Engineering Science and Mechanics
* University City Science Center, Philadelphia, PA
problem of waste generation is to reduce or eliminate the
waste at its source.
University City Science Center (Philadelphia, PA) has begun a
pilot project to assist small and medium-size manufacturers
who want to minimize their generation of waste but who lack
the in-house expertise to do so. Under agreement with EPA's
National Risk Management Research Laboratory, the Science
Center has established three WMACs. This assessment was
done by engineering faculty and students at the University of
Tennessee WMAC. The assessment teams have consider-
able direct experience with process operations in manufactur-
ing plants and also have the knowledge and skills needed to
minimize waste generation.
The pollution prevention opportunity assessments are done for
small and medium-size manufacturers at no out-of-pocket cost
to the client. To qualify for the assessment, each client must
fall within Standard Industrial Classification Code 20-39, have
gross annual sales not exceeding $75 million, employ no more
than 500 persons, and lack in-house expertise in pollution
prevention.
The potential benefits of the pilot project include minimization
of the amount of waste generated by manufacturers, and
reduction of waste treatment and disposal costs for participat-
ing plants. In addition, the project provides valuable experi-
ence for graduate and undergraduate students who participate
in the program, and a cleaner environment without more regu-
lations and higher costs for manufacturers.
Methodology of Assessments
The pollution prevention opportunity assessments require sev-
eral site visits to each client served. In general, the WMACs
follow the procedures outlined in the EPA Waste Minimization
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Opportunity Assessment Manuaj(EPA/625/7-88/003, July 1988).
The WMAC staff locate the sources of waste in the plant and
identify the current disposal or treatment methods and their
associated costs. They then identify and analyze a variety of
ways to reduce or eliminate the waste. Specific measures to
achieve that goal are recommended and the essential support-
ing technological and economic information is developed. Fi-
nally, a confidential report that details the WMAC's findings
and recommendations (including cost savings, implementation
costs, and payback times) is prepared for each client.
Plant Background
Approximately 140,000 finished water craft outboard motors
are manufactured by this plant, which is a final assembly
facility. It operates 2,000 hr/yr.
Manufacturing Process
Three basic subunits received from other manufacturing plants,
component parts, hardware, paint and primer, and decals are
used to produce the outboard motors. The production opera-
tions required can be classified as lower-unit subassembly,
power-head subassembly, motor cover subassembly, and final
assembly. Each of the production operations will be described
here.
Lower-unit Subassembly
The lower units, which are received in two parts, are bolted
together in this plant. First, the connection surface on each
part is polished and then a primer coating is applied. After
coating, the part surfaces are cleaned manually.
Lower-unit subassemblies are then sent through a five-stage
washer in preparation for painting. Following the final rinse of
the five-stage washer, water is removed from internal surfaces
and cavities with pressurized air. Masking is applied to protect
areas of the lower units that do not require painting and then
the subassemblies are conveyed through a dry-off oven for
further water removal.
Primer is applied in one of two primer spray booths where the
required coating is manually applied with electrostatic spray
guns. The subassemblies are then conveyed through a curing
oven. Next, the units are cleaned and conveyed through one of
the topcoat spray booths where the final cosmetic coating is
manually applied. The subassemblies are then conveyed
through a final curing oven.
The finished lower units are inspected for defects and any
rejected units are rewashed and repainted. Masking is manu-
ally removed from accepted parts, which are transferred to final
assembly.
Power-head Subassembly
Various types and sizes of power heads (internal combustion
engines) are received in almost ready-to-use condition. Vari-
ous parts including carburetors, solenoids, and starters are
bolted onto the power head subassemblies using metal fasten-
ers that have been dipped in a lubricant. The power-head
subassemblies are then transferred to the final assembly area.
Motor Cover Subassembly
Motor covers are received as unpainted fiberglass shells. The
shells are processed through a three-stage washer for grease
and dirt removal. Next, the clean motor covers are conveyed
through a spray paint booth where primer is manually applied
with high-volume low-pressure spray guns. The primer is then
cured in an oven.
Following primer curing, the covers are conveyed through one
of two spray booths where either a basecoat or a topcoat is
applied. The motor covers that receive basecoat paint are
conveyed through a flash-off tunnel, where some drying oc-
curs, to one of two clearcoat paint booths where a clear finish
is applied over the basecoat.
Motor covers from the clearcoat booths and covers from
topcoating are conveyed through an oven for curing. The
completed motors are inspected for coating imperfections and
rejected covers are transferred to a sanding booth and then
back to the 3-stage washer for reprocessing. Accepted covers
are transferred to a motor cover detailing operation where
decals and molding are attached manually. The finished cov-
ers are transferred to final assembly.
Final Assembly
In final assembly, power heads are bolted onto lower units
which are then filled with gear-case oil. The assembled motors
are tested in water tanks. Units that fail testing are repaired
and retested. Accepted motors are degassed using compressed
air.
Finally, the motor covers are placed over the power-heads and
attached to the power units. The completed motors are then
spot-cleaned as needed and any required touch-up painting is
performed. Finished motors are packaged and shipped to
customers.
An abbreviated process flow diagram for outboard motor manu-
facture is shown in Figure 1.
Existing Waste Management Practices
This plant already has implemented the following techniques to
manage and minimize its wastes.
Wet scrubber paint booths have been converted to a dry filter
system in order to eliminate the generation of a wastewater
stream containing hexavalent chromium.
The cleaning process for small paint pots has been converted
from a simple solvent rinse to an automatic solvent spray
cleaning system in order to reduce the quantity of solvent
used.
A crank-case oil waste stream has been eliminated by
collecting spills and drips and reusing them.
Approximately 50% of raw material shipments are received
in reusable packaging.
Cardboard packaging and office paper are recycled.
Clearcoat paint application has been converted to robotic
paint application in order to achieve increased paint transfer
efficiency and improved coating appearance.
Pollution Prevention Opportunities
The type of waste currently generated by the plant, the source
of the waste, the waste management method, the quantity of
the waste, and the annual treatment and disposal cost for each
waste stream identified are given in Table 1.
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Table 2 shows the opportunities for pollution prevention that
the WMAC team recommended for the plant. The opportunity,
the type of waste, the possible waste reduction and associated
savings, and the implementation cost along with the simple
payback time are given in the table. The quantities of waste
currently generated by the plant and possible waste reduction
depend on the production level of the plant. All values should
be considered in that context.
It should be noted that the economic savings of the opportu-
nity, in most cases, results from the reduction in raw material
and from reduced present and future costs associated with
waste treatment and disposal. Other savings not quantifiable
by this study include a wide variety of possible future costs
related to changing emissions standards, liability, and em-
ployee health. It also should be noted that the savings given
for each opportunity reflect that pollution prevention opportunity
only and do not reflect duplication of savings that may result
when the opportunities are implemented in a package.
This research brief summarizes a part of the work done under
Cooperative Agreement No. CR-819557 by the University City
Science Center under the sponsorship of the U.S. Environmen-
tal Protection Agency. The EPA Project Officer was Emma
Lou George.
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2-part Lower Units
5-Stage
Washer
Pre-paint
Preparation
Primer
Application
Power Add-on
Heads parts
Completed
Lower Units
Completed
Power Head
Units
Finished
Product
Completed
Motor Covers
Fiberglass
Motor Covers
Pre-paint
Preparation
Primer
Application
Basecoat &
Topcoat
Application
Clearcoat
Application
Figure 1. Abbreviated process flow diagram for outboard motor production.
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United States
Environmental Protection Agency
National Risk Management Research Laboratory (G-72)
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/S-95/018
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