Preparation and refinishing area

When planning your bodyshop, productivity, health,

safety, and environment regulations must all be taken

into consideration.

Start with the preparation area. There must be

space to pressure wash vehicles to get cleaner

paintwork before they enter the paint shop.

The dust created by sanding in the preparation

stage must be prevented from being drawn into

the paint area. The best solution is an efficient

extraction system or extraction tools. Avoid walls

or curtains as they lead to rigid space allocation

and are inflexible because they prevent bodyshops

reacting to variable workloads. If possible, design

the paint shop so that the vehicle moves forward

in a relatively straight line or an easy loop, and

try to keep it inside the workshop to avoid the

problem of coming into contact with dirty, dusty

air.

Ideally the refinishing area should form a selfcontained

area separate from the mechanical and

repair side of the workshop and the preparation

area. The main objective is to minimize the amount

of handling of the vehicles by arranging for a flow

system from the vehicle’s entry to its exit from the

spray booth, thus preventing any dust entering the

spray booth. Consequently spray booths and ovens

can be used to their full capacity throughout the

working day.

In the paint shop, health and safety regulations

will dictate many decisions and must be taken

into account in your plans. The ramifications of

the EPA and COSHH legislation are far reaching

for all bodyshops. In effect, any bodyshop currently

operating without a properly constructed

fully operational and well maintained spray booth

is operating outside the law and risks summary

closure.

A spray booth is in most cases the single biggest

purchase decision made by the bodyshop owner.

Most bodyshops are now fitting combi-booths.

A combi-booth is a combined spray booth and

low-bake oven with an electrically controlled operational

cycle which provides the correct temperature,

filtration and lighting requirements for the

spraying and baking of paint. The purpose of the

combi-booth is to provide an efficient, clean area,

free of humidity and within the temperature band

20–25 °C. The booth must be sealed off to prevent

overspray escaping into the workshop, and must be

force ventilated to remove solvent fumes and

microscopic paint particles whilst drawing in clean

and dust-free air. Once spraying is completed, the

combi-booth can be put into the bake cycle in

which the internal booth temperature is raised to

promote rapid curing of the paint. One important

point to consider is the choice of spray booth. This

must meet all the requirements of the EPA in relation

to the throughput of air and the placement of

the exhaust stack. This point is particularly important

in residential areas. The booth must operate

under negative pressure and to comply must be

fitted with a pressure gauge. As a further precaution,

emissions from spray booths should be tested

at least once a year to monitor particulate matter

emitted. The EPA stipulates that concentration of

total particulate matter in final discharge to air

from the booth should not exceed 10 mg/m3.

When constructing the paint store room, remember

to provide space for the mixing system and

for the safe storage of paint. Again, follow all the

necessary regulations.

Valeting

The vehicle should now be back at the valeting bay

for both interior and exterior valeting, to emerge as

good as new with the minimum wasted time.

Careful valeting work can transform the final

appearance of the vehicle, thus creating customer

satisfaction by returning the car looking like it did

when new. If the customer’s first impressions on

collecting the vehicle exceed expectations, he will

be more than willing to recommend the comapany’s

quality of service.

First aid

First aid equipment should be supplied at set

points throughout the workshop, and staff should

be encouraged to attend first aid classes. The

Health and Safety at Work Act requires that

where more than 50 personnel are employed, one

qualified first aid person must be appointed.

Fire fighting equipment

Consult the local fire officer regarding fire points

and types of fire appliances, exits, and fire doors.

Organize staff fire drill and training procedures,

Bodyshop planning 509

and make sure that all fire extinguishers are

maintained.

15.3 Bodyshop heating

The body repair shop can be a difficult building to

heat because of the very nature of the work that is

carried out. First, it needs to be a reasonable height

so that vehicle bodies can be elevated and moved

about easily; and secondly, doors are constantly

being opened and shut to allow for the movement

of vehicles in and out of the workshop.

Careful consideration of bodyshop heating

requirements will not only result in energy consumption

savings but also make the bodyshop

more comfortable. Whatever type of heating systems

are used, care should be taken to ensure that

heaters are placed where they will not interfere

with work in progress, will not take up unnecessary

floor space, and will provide employees with

the maximum benefit.

Most of the conventional methods of space

heating can be found in bodyshops, ranging from

portable gas fired units through wet systems to

radiant systems.

Radiant heating

Infrared (IR) heating is the transfer of energy by IR

electromagnetic radiation; this is the portion of the

electromagnetic spectrum between visible light

and the top section of the radio-radar wavebands.

Any object will emit IR energy; the higher

the temperature, the more IR radiation is emitted.

Therefore when two objects are adjacent to one

another and one is hotter than the other, there will

always be an exchange of heat from the hotter object

to the cooler one. Radiant heaters operate by the

transfer of heat to solid objects rather than by heating

the air itself; therefore high-ceiling buildings can be

heated with a high degree of efficiency. By installing

radiant heaters above a cold concrete floor, there

will be a transfer of IR radiant energy downwards

towards the cold concrete, which will absorb energy

until it becomes warm. Other objects at floor level,

such as vehicles, benches and machinery, as well as

the walls, will become warm either by receiving

direct IR energy or by the transfer of energy from the

floor. All of these items become secondary heat

sources, transmitting energy into the surroundings of

the workshop. Ceiling-mounted radiant heating units

are ideal for bodyshop use in that they do not take

up usable space and encroach into the working

area; however, they are not suitable where the ceiling

height is less than 3.5 metres. Also radiant heat

absorbed by its surroundings does not easily escape

through service doors: therefore heat loss is reduced

and a saving is made on energy costs. Furthermore,

heating the floor keeps it dry, and the fact that vehicle

bodies become heated reduces problems associated

with condensation as the cold vehicle bodies are

brought into a heated environment.

Electric heating

Electric spot heating allows comfortable heat to be

concentrated where and when it is wanted. Linear

quartz heaters can be used for the spot heating of

specific work areas, for zone heating of a particular

area of the bodyshop, or for full coverage heating.

For spot heating, the heaters should be positioned

about 3–5 metres apart, at a height of approximately

2.5–3.5 metres from the floor, depending upon the

heater rating. Heaters should be rated at 1.5 kW for

sheltered locations, rising to 3 kW or even 4.5 kW

for more adverse conditions. For zonal heating, the

heating requirement should be calculated on the

basis of 150–300 W/m2. The actual value selected

will depend upon the state of the building, internal

draughts, etc. If the zone is more than about

15 metres wide, then additional rows of heaters may

be required. For full coverage, the heaters should be

positioned around the perimeter of the building at

spaces of about 4–6 metres, using load densities of

100–200 W/m2 based upon heat loss calculations. If

the building is more than about 17 metres wide,

additional heaters can be installed.

When installing these heaters, the general principle

is for the heater to be angled down at about 45

degrees when wall mounted and up to 90 degrees

when mounted overhead.

As with all forms of heating, care should be

taken with these heaters if there is a risk of combustible

dusts or flammable gas hazards. The

lamp/filter assembly is the hottest part of the

heater, with surface temperatures of 750–800 °C,

broadly similar to the surface temperature of the

lamp in a tungsten halogen floodlamp. In case of

concern over this point, consultations should be

held with the factory inspector.

510Repair of Vehicle Bodies

Gas heating

Radiant gas heaters come in two forms: tubular and

ceramic plaque.

The radiant tube heater typically incorporates

single or twin emitter tubes through which hot

gases are drawn by a vacuum fan to produce the

IR heat. An automatic burner fires into the mouth

of the emitter tube, providing rapid warm-up

without any need for preheating. The burner operates

in a totally enclosed combustion chamber

with the safety controls housed separately to protect

them from dust and contamination. If it is

required to exhaust the products of combustion to

the atmosphere, the individual heaters can be

linked into a manifold system with one exhaust

fan. Typical capital costs are about half those of

an equivalent central boiler system and about the

same as a ducted warm air system. The heaters

can either be wall mounted and inclined, or suspended

at heights from 3 to 12 metres. The units

are able to cope with high air exchanges and they

can also reduce the spread of airborne dust and

fumes.

Ceramic plaque heaters are silent in operation

and are marketed as being ideal for spot heating

and for the heating of lofty uninsulated buildings

which suffer high air movement. They incorporate

a totally enclosed burner with a skirt to protect the

ceramic plaque from cold air washing over the hot

surface.