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Cleaning - Do You Know Where Your Dollars Are?
By Ed Sunkin
Cleaning parts in the machine shop doesn't
come cheaply. According to Automotive Rebuilder's Machine Shop
Market Profile about 15.2% of engine machining and rebuilding
production work involves disassembly and cleaning. According to
rebuilders that we surveyed, disassembly and cleaning accounted
for the highest percentage of total rebuilding production time
in the shop. So there can be significant benefits to reducing
cleaning costs in the shop.
It's been estimated by many in the rebuilding
industry that, depending on the product line and the type of cleaning
equipment and system in use, cleaning accounts for 30 cents or
more of each dollar spent on shop overhead. Cleaning costs can
come from many different areas. First, there's the initial cost
of the cleaning equipment itself, be it a thermal system such
as convection, rotisserie or direct flame ovens, wet cleaning
which includes hot tanks and other units designed to clean with
hot water or chemical solutions, jet spray and pressure washers
and ultrasonic cleaners and abrasive cleaning, which includes
shot and bead blasting and shot removal equipment.
For a list of manufacturers and suppliers of
cleaning equipment, refer to Automotive Rebuilder's annual Automotive/Truck
Purchasing Directory contained in the January 1998 issue.
Second, there's the costs for cleaners, solvents
or media used. The cleaning method you use in your shop will dictate
these costs. Aqueous cleaning comprises a wide range of methods
that use water, detergents, acids and compounds to displace soil
rather than dissolving it in organic solvent. Aqueous cleaning
has been found to be a viable substitute for many parts cleaning
operations currently using solvents. Its principle disadvantage
is that the parts are wet after cleaning and carbon steel parts
rust easily in this environment. The additional cost of a rust
inhibitor should be considered with this type of cleaning.
Techniques for reducing waste costs from aqueous
cleaning include switching to detergent-based cleaners. Many shops
are switching from solvent or caustic-based cleaners to less hazardous
detergent-based cleaners. Operators should check that the type
of cleaner used consists of surfactants that are good detergents
but are poor emulsifiers (stable oil emulsions limit reuse of
the cleaner and hasten its disposal). Agitation of the bath during
use keeps the solids in suspension. Following prolonged periods
of inactivity, however, the oily solids separate via flotation
or settle to form a bottom sludge. Solution strength is maintained
and bath life prolonged by removing these solids frequently.
Other costs associated with cleaning include
labor, utilities to operate cleaning equipment, and shop towels,
hand cleaners and uniform laundry services for employees. You
also should consider water, sewer discharge and disposal of waste
as cleaning expenditures. As with all consumables, the price of
water and sewer continues to rise in many areas. In most municipalities,
the more water you purchase - and usually the more you send to
the sewer - the higher the price. The rising cost of water is
a strong incentive for shops to use less.
So now that you know your shop is surrounded
by cleaning costs, how can you go about reducing them and stretch
your cleaning dollars?
One simple way to reduce cleaning costs is
to monitor solvent composition in your cleaning units. Often in
the shop, the decision to replace dirty solvent is made arbitrarily.
At times, much solvent is disposed of prematurely. Monitoring
solvent used in equipment will help ensure that the cleaning agents
are replaced only when the solution is truly dirty, thereby saving
you money on solvents.
You should also maintain solution quality.
In addition to the dirt, excessive consumption of alkaline cleaner
also can be due to using air for agitation and hard water for
make-up. In some applications, the decrease in cleaner effectiveness
due to dirt and sludge can be equal to the carbon dioxide and
hard water salts of the water used to clean parts. Consider changing
to mechanical agitation by means of jet sprays and use of demineralized
water in place of hard water for make-up.
Analytical checks of solution strengths, performed
by the operator using simple titration techniques, should be made
routinely. The correction of solution strength by making small
and frequent additions is more cost-effective than making a few
If your shop is a Small Quantity Generator
(machine or rebuilding shop generating between 220 lbs. and 2,200
lbs. of hazardous waste a month), you'll need to obtain and use
an EPA identification number. To obtain this number, shops should
contact their state's hazardous waste management agency or the
hazardous waste division of their regional EPA office and request
EPA Form 8700-12- Notification Of Hazardous Waste Activity. A
booklet containing a form with instructions and portions of EPA
regulations to help you identify your shop's waste will be sent
The use of solvent sinks for small parts washing
either on an owned or leased basis is being accepted as general
good practice. According to the EPA, more than 95% of automotive
repair operations have some type of solvent sink. When considering
cost reductions in the shop, consider contracting with a solvent
service company. For a monthly fee, solvent service companies
such as Safety-Kleen Corp., Safe-Way Chemical Co. and many others
offering this service, will pick up dirty solvent, clean and maintain
the solvent sink, and refill the sink with clean solvent. Depending
on the arrangement, solvent sinks may be owned by the shop or
leased from the solvent service company. The cost for contracting
with a solvent company may be less than the combined cost of solvent
purchase, tank maintenance and waste disposal.
Many rebuilders rent or lease parts-cleaning
units and solvents from solvent service vendors. These units usually
consist of a parts-cleaning sink or compartment mounted over a
drum of solvent. The rental is usually part of a package deal
whereby the service vendor maintains the unit, provides fresh
solvent, removes dirty solvent (either for disposal or recycling),
and provides appropriate paperwork. This method of solvent management
is very common.
According to the EPA, rebuilders subscribing
to this type of service may be able to reduce the amount of hazardous
waste they generate by examining the condition of the solvent
when it is exchanged. If the solvent can still effectively clean
parts, then the amount of time between solvent exchanges could
be increased. Customers could arrange for exchanges of solvent
to be as infrequent as possible. Also, the number of parts cleaning
units in use could be examined to see if the number can be reduced.
These two management techniques could help reduce the amount of
hazardous waste generated.
You may also consider installing on-site solvent
recovery equipment. Purchase of an on-site solvent recovery system
is often viewed as a viable waste minimization option for solvent
wastes. These stills utilize a bag liner (for ease of cleaning)
and microprocessor control.
Based on the results of California Department
of Health Services assessments, the low volume of solvent normally
used at most small to medium repair operations does not justify
the added expense of on-site solvent recovery equipment and maintenance
costs. For large operations that do generate significant volumes
of solvent, labor costs to operate the equipment and additional
costs for disposal of waste residues are generally not competitive
with current solvent sink lease and maintenance service operations.
Using a lease service may help control your
shop's cleaning expenses. Similar to solvent lease arrangements,
some companies offer a leasing service for hot tanks and jet spray
washers. Hot tank arrangements include monthly leasing of a hot
tank and monthly general maintenance service with removal of a
set number of gallons of solution and sludge and recharge of solution
with caustic or alkaline detergent and make-up water. Jet spray
washer arrangements include monthly leasing of a jet spray, and
monthly general maintenance service with removal of 10 gallons
of solution and sludge and recharge of solution with caustic or
alkaline detergent and make-up water.
Some shops are turning to bake-off ovens as
a popular approach to reduce some cost in the cleaning process.
Bake-off ovens are designed to pyrolize the dirt and grease, leaving
a dry residue that can be brushed off. In most cases, abrasive
blasting of the parts is required to remove all of the residue.
According to Lyle Haley, sales/marketing manager for Peterson
Machine Tool, Inc., the advantage of a bake-off oven is that it
produces a small volume of dry solid wastes compared to a large
volume of liquid waste. "Disposal of the dried powder residue
from heat cleaning ovens is even easier and more cost effective
than removing sludge from the liquid filter systems, " Haley
But the disadvantages of bake-off ovens may
include utility costs, a potential for increased air emissions
and the cost for abrasive blasting equipment and media.
Then there's the issue of wastes generated
by your shop and costs to remove them. It is important to hire
a reputable, financially stable and state-approved waste remover
who will dispose of your shop wastes legally. According to the
EPA, if your hazardous waste is dumped illegally, your shop could
be held responsible. And clean ups of hazardous wastes don't come
In some areas, wastewater can be discharged
to a municipal wastewater treatment plant; you may be required
to obtain a permit from the municipality. If wastewater is discharged
to surface waters, (ponds, rivers, lakes, etc.) via pipe or storm
sewer, a discharge permit must be obtained. Check with local and
state authorities to determine requirements and the appropriate
permitting authority. If a wastewater treatment plant is not available
or will not accept your wastewater, or if you do not have a discharge
permit, route your wastewater to a tank or container for proper
collection and disposal by a licensed waste hauler.
If you are rearranging your shop or moving
to a new location, there may be added costs to consider. Floor
drains should be connected to an oil/water separator to treat
wastewater prior to discharge to sewers, surface waters, or containment.
It is preferable to equip the separator with an emergency shut-off
to prevent spills from entering the sewer, or discharging directly
to surface waters. It is important to inspect the separator periodically
and arrange for waste removal by a licensed waste hauler when
Do not discharge toxic or hazardous wastes
to drain fields, dry wells, cesspools, pits, separate storm drains,
sewers, surface waters, or septic tanks. Otherwise you may be
in violation of federal, state or local requirements and subject
to monetary penalties.
For those shops that acquire spent oils during
rebuilding or remanufacturing and are looking for a cost effective
way to dispose of these hazardous lubricants, burning may be the
Clean Burn, Inc., of Leola, PA, manufactures
coil tube boilers which burn used crankcase, hydraulic and ATF
oils to provide a reliable, inexpensive source of hot water that's
used in parts washing and other closed-loop heating operations.
According to Clean Burn, burning used oils
recovered from vehicles or equipment relieves shops of cradle-to-grave
environmental liability for off-site hauling and disposal of used
oil, while greatly reducing high energy costs to heat water.
Cleaning solution technology
In an effort to provide alternatives to caustic
cleaners and meet guidelines of the Clean Air Act, many chemical
cleaning manufacturers have changed or developed formulas that
are designed not to hurt the environment, or a shop's pocketbook.
Real-Green, from Oakite Products, Inc., is
a heavy-duty cleaning and degreasing solution that is based on
a blend of terpenoids and terpene alcohol. Known as biomass technology,
this approach uses materials such as vegetables, corn, rapeseed,
soybean, kenaf and trees to create products that traditionally
contained chlorinated or chlorofluorocarbon solvents. According
to its developers, Real-Green's biggest benefit extends to shop's
wallets. Cleaning personnel can use as little as one part Real-Green
to up to 150 parts water for cleaning and degreasing automotive
parts, as well as rebuilding equipment.
Another cleaning solution was used to help
a leading brake rebuilder of antilock braking systems reduce parts
washer downtime and waste water disposal costs by nearly 90% by
switching its aqueous cleaner.
Last year, LucasVarity Kelsey-Hayes, changed
its brand of aqueous parts cleaners to the environmentally-friendly
ARMAKLEEN® M-Auto available from Church & Dwight at its
rebuilding facility in Wixom, MI.
The ABS units - each consisting of a painted
motor, aluminum main valve body with iridite coating, plastic-coated
wire, and other components with different types of plated surfaces
- were typically coated with oil, grease, various underhood contaminants,
and road grime.
LucasVarity Kelsey-Hayes' Quality Control Supervisor
Ron Hasselbach, said he had searched for several years for an
alternative to the caustic-based cleaner used to clean the ABS
units sent in for inspection and rebuilding. Hasselbach said although
the caustic-based cleaner did get the ABS units clean, the equipment
had to be shut down and thoroughly cleaned in addition to changing
the wash bath out every week to maintain cleaning effectiveness.
Hasselbach and Manufacturing Associate Bob
Hapney said they had tried several different cleaners, though
none provided significant cleaning or cost advantages over what
the company was already using.
Last year Hasselbach came across some information
in a trade publication about a line of environmentally friendly,
carbonate-based aqueous cleaners used successfully in automotive
parts cleaning applications. The new product could be used in
his existing equipment and was about the same price as the caustic-based
Hasselbach and Hapney compared the caustic
cleaner with the new one from ARMAKLEEN by systematically charting
the operating parameters and other relevant aspects relating to
the use of the products to view any possible cost efficiencies.
According to Hasselbach, a 20 to 30° F difference in operating
temperature for the cleaner would certainly have some impact on
energy costs in the long run, though assigning a dollar amount
to this decrease in electricity consumption would be difficult
and probably not very accurate under the circumstances. Instead,
the two chose to identify cost savings related to downtime and
The reduction in parts washer downtime means
two items that translate into greater productivity. First, cleaning
of the ABS units can occur more efficiently without weekly interruption.
Second, the person responsible for cleaning out the washer each
week is free to perform other duties in the shop. Depending on
cleaning volume and labor costs, the amount of money this represents
would vary from shop to shop. According to ARMAKLEEN, the cleaner
switch at LucasVarity Kelsey-Hayes provided about 188.5 hours
saved annually and a 90% reduction in downtime.
LucasVarity Kelsey-Hayes also found waste disposal
reductions. The company has a main waste tank with the capacity
to hold three dumps from their parts washer. So with their bath
life with their original cleaner lasting only one week, a waste
disposal contractor was needed every three weeks to empty the
But the bath life of the new product was eight
weeks instead of just one, so the waste disposal interval was
extended to 24 weeks or about twice a year.
Another occurrence Hasselbach and Hapney noticed
with the new product was the oil skimmer on the side of the washer
worked more efficiently by removing larger amounts of oil over
a shorter period of time. Water at the top of the small tank adjacent
to the oil skimmer was very dirty and oily, and the container
catching the oil collected by the skimmer needed to be emptied
fairly often, something that didn't occur with the caustic-based
This oil-splitting property of the new cleaner
provided favorable financial benefits to LucasVarity Kelsey-Hayes
Since the oil splitter separated out the oil from the wash bath
and it was more easily removed by the oil skimmer, soil and oils
were not recirculated into the bath. This resulted in longer bath
When more soil and oils are removed by the
skimmer, less waste will accumulate in the cleaning equipment
itself. Hapney said when using the new product, only a very thin
layer of sludge had to be removed from the bottom of the tank
during the shutdown at eight weeks as opposed to the large amount
of sludge removed each week when the caustic solution was used.
And since the inside of the parts washer itself
was a lot cleaner, both downtime and electrical consumption was
reduced. "Our heater elements are working a lot more efficiently
now," Hapney said. "We used to have to wire brush them
every week to remove sludge."
Hasselbach recommended rebuilders who want
to make the right choice for a parts cleaner need to look at the
big picture, adding the product comparison he made did not center
on superior cleaning effectiveness. "Carefully compare all
aspects of the products you're considering," he said. "Systematically
identify cost efficiencies and calculate the benefits. And, make
sure you understand why one product is providing the efficiencies
and cost savings you want. It's the best way to get the product
for your needs."
Finding the right application
Changing cleaning methods or cleaning equipment
can be a costly step for a shop. Researching is important. Don't
be afraid to ask the manufacturer questions and don't make a decision
by looking into only one type of system or company. Ask for some
kind of cleaning demonstration on your company's soiled parts.
Many manufacturers will conduct these evaluations at a testing
facility on equipment similar to the unit being considered. Another
good way to research cleaning methods is to attend various trade
shows presented by the Engine Rebuilders Association (AERA) and
Automotive Parts Rebuilders Association (APRA). Many cleaning
equipment and product manufacturers attend these shows to demonstrate
Talk to others rebuilding the same products
as you, but realize there may be some differences. Steve Winters,
president of A.R.E. Industries, Inc., Wichita, KS, said when dealing
with customers, he sells only what the customer really needs.
"A big mistake a lot of customers make is that they want
a machine just like their buddy uses, even though their buddy's
shop is much larger or does twice the volume of work," he
said. "The problem is even though a customer may have seen
a cleaning unit operate and they feel comfortable with it, they
may not need that size of equipment to handle their cleaning requirements.
When a customer over-buys, cost-efficiency is reduced. The customer
ends up paying more for the equipment, the parts take longer to
clean, and the cost is the same whether they clean one or 10 parts."
But what if the company outgrows the equipment
they have? Winters said he offers trade-ins to allow the company
to upgrade their cleaning equipment as dictated by their growth.
Rebuilders should research whether the company they buy new equipment
from now will allow trade-ins of that equipment for upgrading
purposes at a later date.
Winters said another way to save money is to
keep your cleaning equipment in proper working order. Rack systems
should be maintained in good condition, free from cracks, rust
and corrosion which can flake off and contaminate the bath. Metal
tanks should be properly coated with protective finishes both
inside and out. Spray nozzles should be inspected regularly to
avoid clogging. "A lot of people think buying filtration
units will solve all of their maintenance problems, but they don't,"
Winters said. "You still have to have a maintenance program.
These accessories don't clean themselves. Without a maintenance
program, shops don't realize how much they are loosing in downtime,
labor costs and most importantly - equipment longevity."
David Zehren, product manager for Georg Fischer
Disa Goff, Inc., Seminole, OK, agreed, saying proper maintenance
will aid in cost savings. "By periodically cleaning machine
and generator tanks, the buildup of heat-reducing gunk on the
heating tube is reduced and therefore it offers a higher heat
efficiency transfer," Zehren said. "When you have gunk
buildup, the burner is less efficient and it requires longer heating
cycles to achieve and maintain the proper operating temperature.
This also causes faster and larger temperature drops in the tank
with slower recovery times."
As long as there is rebuilding, there will
be the need to clean, along with the costs that go with it. How
your shop chooses to reduce these costs will depend on thorough
research. Remember whatever you decide to change, the right decision
is the one that not only improves part cleaning quality, but saves
you money as well.