But, what if a shop could use a computer to control exactly how
much air enters the spraybooth during the spray cycle and bake
cycle? What if a computer could tell you when to change the filters,
could open and close dampers, start and stop fans, and turn burners
on and off?
What if that computer could be called by other
computers, and – from anywhere in the world – a person could "watch"
the equipment? What if it were possible to know from a remote
location if the spraybooth is on or off, if the lights are on,
if the door is open, and what the outside air temperature and
the inside booth temperature are?
The "what ifs" have become reality
at Westborn Collision in Dearborn, Mich., where all of the above
– and more – is being done by computers.
How It Started
Westborn Collision has been in business since
1960, and since then, has relocated once and added on to its existing
building twice. When Westborn used up all of its available "green
space" for growth, it became necessary – in order to keep
up with the growing business demand – to look for ways to increase
At this point, Westborn already had four downdraft
spraybooths and a prep station, so co-owners Roy and Kevin Mott
opted for a new shop layout and additional equipment to move the
vehicles through the paint shop faster.
First, the Motts moved the paint booths to
a location that would allow them to be converted to drive-through
booths. Second, they looked for a way to add one more booth in
the future, which is what led to the idea of installing all of
the spraybooth mechanicals outside the building.
The air makeup units were installed on the
building’s roof, and duct work was added to attach them to the
booths. The exhaust fans were located outside the building, too,
and were connected to the paint booths with underground ducting.
During the construction, the floor was torn
up and dirt was removed, in some areas 6 feet below grade. The
four paint booths were installed next to each other with as little
as 2 inches between them, allowing space for a future booth without
expanding the physical size of the building.
To prepare the cars for the paint booths,
nine prep stations were installed. As in most prep stations, the
air can be recirculated when doing sanding operations or exhausted
to the outside when painting, priming or sealing. Each station
also has its own surrounding curtain wall to separate work spaces
and to confine contaminants to the protected area.
Where the Computer Comes In
All the prep stations are completely controlled
by a computer, and all their vital functions are run by a computer
– meaning exact control of accuracy, along with off-site monitoring.
The system can be accessed from anywhere there’s a phone line
and a laptop computer equipped to connect to Westborn’s computer.
Not only does the computer know when someone
is spraying or sanding in one of the nine prep stations but, as
soon as a spray-gun trigger is pulled, it turns on the fan, opens
the outside exhaust damper and continues to exhaust the air to
the outside until two minutes after the spraying has stopped!
If someone is just sanding, the computer knows
to turn the fan on, leave the outside exhaust damper closed and
return the air to the shop. There are no buttons to push or switches
to turn – everything on the prep stations is automatic. (By the
way, the computer also tells Roy and Kevin when to change the
floor filters and when to change the bag filters.)
The computer controls the building’s ventilation
system as well. Every time air is exhausted in the building, the
computer tells a very large air makeup system to bring in an equal
amount of fresh air, keeping the entire building in a positive
pressure to the outside. In the winter when one of the six overhead
doors is opened, you won’t feel any cold drafts come into the
There’s more … In order to maintain the
positive building pressure, the computer will only allow up to
four of the prep stations to exhaust air to the outside at any
given time. If painters try to spray in five stations at a time,
the computer won’t allow the compressed air to enter that prep
station until one of the other four stops spraying.
As for the shop’s compressed air, it’s supplied
by a 50-horsepower rotary-screw compressor. This type of compressor,
as efficient as it is, actually uses a large volume – 7,500 cfm,
as much as some single prep stations use to cool them down as
they operate. In the winter, the air is expensive because it has
to be replaced by heating outside air – which is where the computer
comes in. The air that’s used to cool the compressor comes from
a special duct connected to both the outside and inside of the
building. The computer mixes outside air with the correct amount
of inside air to maintain a predetermined air temperature into
the compressor. Since in Michigan it’s expensive to exhaust air
in the winter (due to having to heat the replacement air), the
computer will return warm air to the building in the winter and
exhaust hot air outside in the summer.
All these changes have resulted in one major
improvement at Westborn Collision – consistency of the paint work
– which Kevin says is the key to maintaining the shop’s high standards.
"[The computer] keeps a constant pressure
in the booth," he says. "When you change all the filters
in a conventional spraybooth, it may be at the proper settings,
but when the filters restrict, you wouldn’t have the pressure
or the balance you need – and you’d lose the consistency.
"[Our spraybooths] are the closest you
can get to what you would find in a factory environment."