"air handling" system can
be a typical large squirrel cage fan
found in many houses, offices, or apartment
houses. There seems to be enough
of these systems floating around used
to fill the needs of the spray room
builder, but if you must buy one new
get at least a ten ton unit. My
room is 20' wide, 30' deep, and 13'
high. With this ten ton unit,
shown hanging from the ceiling outside
the spray room, my air changes about
once every 3 to 5 minutes depending
on the size of the vehicle being sprayed.
The best thing about this all electric
system is that I can also control the
temperature in the room using a thermostat
in the room. With the use of baffles
I can bring air in to the booth from
outside the building, from other parts
of the shop, or recycle the air in the
room in order to warm it more thoroughly.
duct my air into these 4' x 6' homemade
filter boxes. The filters cost me about
$80 each to replace every two years
of pretty steady use. Those panels
are hinged 2" x 3" frames
with 1/4" wire mesh under the filters.
I use a product from American Air Filter
(800-501-3146) called "Fusion Media."
You buy it in precut sheets, you dictate
the room is done by the incoming air
while air in the room is forced out.
Using this concept of a "positive
pressure" environment, you overcome
many problems created by the "negative
pressure" environment created by
the fan in the window or wall blowing
out. Dust control is the main
reason for this pressurizing.
A negative pressure brings dust from
every crack and crevasse in the room
while positive pressure means you only
need to deal with the incoming air through
constructed the walls of galvanized
steel studs and gypsum board, framing
the openings with pressure treated lumber.
The lumber that came in contact with
the floor, walls, and ceiling was caulked
well during installation so leakage
is nearly non-existent. This wall
went up in a day.
doors are made of Styrofoam and set into
the opening with the edge sealed with
a plastic "V" strip on the sides
and to and a rubber bead fastened to the
bottom. It's held in place with
a cross bar. When removed,
it hangs on the wall out of the way.
booth has a normal size 3' x 7' door and
a 4' x 8' door, so when the booth is not
being used for painting it's easy to move
between bays. Also note in the picture
to the left, the light recessed in the
wall and covered with plastic. Access
to the light is gained from outside the
is critical, if you can't see the surface
properly that you're painting, your
results will show it. Lighting does
two basic things: first, it shows you
variations in color; second it shows
you variations in texture. The light
needs to be bright enough to highlight
these variables without being so bright
that it overpowers your sight while
looking at the surface from different
angles. I use inexpensive 4 foot shop
lights purchased from a chain hardware
store. They're installed about 18 inches
above the floor behind a sealed plastic
cover. These two bulb fixtures are mounted
on a hinged plywood panel which allows
for bulb changing. I have two
of these 4 bulb units on each side of
the work space which allow for good
color perception, and (because of the
tube length) they also give a reflection
which shows texture on the surface,
allowing me to tweak the surface for
orange peel etc.
floor is pitched slightly toward the
overhead door which allows the floor
to be washed and rinsed easily.
The floor is painted in order to keep
the concrete sealed so that it doesn't
generate dust. I was using an
epoxy floor paint for a long time then
found that I liked latex floor paint
much better, it's easier and cheaper
to use, and I do it more often to keep
the place bright and clean. I
fooled with many colors on the floor
but have found that a light gray worked
best for me, it didn't distort paint
colors and it helped reflect a little
light that darker colors would absorb.
Before any full paint job or other critical
spraying operations the floor is dampened
to help with dust.