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Ford Focus RS (2011 year). Instruction - part 136

• Polyester material not covered.

• Sweat from hands.

• Salts and minerals in sanding water.

• Spray air contaminated.

Repair of damage:

• Sand away damage, matt sand remainder of

surface, clean with silicone remover, fill and
re-paint.

Etching

The base paint is etched by the clear lacquer. This
causes the aluminum pigments to change their
alignments. The color of the etched base paint
seems more grey than that of normal base paint.
Result is that the surface structure of the clear
lacquer becomes increasingly more matt.

Cause/damage pattern:

• Base painted too wet.

• No intermediate flash-off time.

• Layers too thick.

Repair of damage:

• Sand and re-paint.

Paint wrinkles/puckering

Lifting/puckering of the paint surface.

Cause/damage pattern:

• First paint not hardened through or can be

etched.

• Areas of clear lacquer which were sanded

through to base paint have not been not isolated
with filler, or with unsuitable filler.

• Unsuitable substrate (e.g. spray can painting

with TPA or nitro).

• Use of unsuitable primer, paint and thinner

materials.

• Paint systems not matched to each other.

• In wet-in-wet process, specified flash-off times

not adhered to.

• Synthetic resin top coat (alkyd resin) worked

over too soon.

Repair of damage:

• After thorough drying, completely remove the

top coat together with the attacked substrate at
the affected areas and re-create a new paint
finish.

• Before applying top coat, rub down the complete

surface.

Cloud formation

Differing, blotchy color/effect formations in
dark/light areas of a metallic paint finish.

Cause/damage pattern:

• Spray gun, spray nozzle, spray pressure not

perfect.

• Varying spray viscosity, spraying method,

flash-off times, spray booth temperature.

• Thinners not suitable.

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Repair of damage:

• Droplet method before clear lacquer application.

• After clear lacquer has thoroughly dried, sand

surface and re-paint.

Spots

Points rising up from the paint film.

Cause/damage pattern:

• Metallic base paint sprayed too dry, so that the

metal particles could not incorporate into the
paint. The clear lacquer could not cover these
vertical standing particles because the spray air
was too hot or the booth temperature was too
high.

Repair of damage:

• After the paint surface has dried, lightly sand it

with grade P800 sanding paper, clean with
silicone remover and re-apply clear lacquer.

Metamerism/color deviations

Noticeable when identical color shades undergo a
change of hue as the light source changes
(daylight/artificial light). Different pigment
composition between original and repair paint.

Cause/damage pattern:

• Use of paints with pigmentation which was not

compatible with the standard, e.g. a green can
be formulated from yellow and blue, or directly
from green.

• Use of an unsuitable mixed or ready made paint

to re-tone.

Repair of damage:

• Repaint using the correct paint.

Washing out

On paint which has been newly applied but not yet
dried, the interaction of surface tension and very
different specific gravities of the different pigments
can lead to swirl-like turbulence which results in
separation of the pigments.

Cause/damage pattern:

• Layer too thick, paint not stirred enough.

Repair of damage:

• Sand and re-paint.

Loss of gloss

Milky, dreary tarnishing of the paint with more or
less even loss of gloss.

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Cause/damage pattern:

• Cold with low air humidity.

• Heat with high air humidity.

• Substrate can be etched.

• Hardener fault or wrong hardener used.

• Paint thinned too much.

• Proportion of pigment too high because of poor

stirring.

• Not optimum drying.

Repair of damage:

• After drying, remove the matt effect by polishing.

If unsuccessful, rub down complete area and
paint again.

Covering ability/areas of thin paint

Different color shades in the surface. The minimum
layer thickness is not achieved here. The effects
range from local minor shade variations through
mottled spray zones to completely missing top coat.

Cause/damage pattern:

• No correct, uniform substrate (effect paint).

• On three-layer systems, wrong filler.

• Insufficient top coat application.

Repair of damage:

• Sand surface and recreate the paint finish.

Flow problems/orange peel

Surface structure bumpy, grained. The surface is
similar to the peel of an orange.

Cause/damage pattern:

• Paint viscosity too high.

• Use of fast evaporating, highly volatile thinners.

• Booth temperature too high.

• Spray gun distance too great, too little material

applied.

• Nozzle too large.

• Incorrect spray pressure.

Repair of damage:

• Small surfaces: fine sand and polish.

• Sand out the surface and recreate the paint

finish.

Dirt embedded in metallic base paint.

Inclusions of contamination in metallic base paint,
of different sizes and shapes (grains or lint).

Cause/damage pattern:

• Dust was not properly removed from the surface

to be painted.

• Paint material not sieved.

• Function of the painting facilities not optimum.

• Filter contaminated.

• Wearing unsuitable clothing.

Repair of damage:

• Sand and repaint.

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Dirt embedded in top coat

Inclusions of contamination in top coat or under
paint layers, of different sizes and shapes (grains
or lint). Optical adverse effect.

Cause/damage pattern:

• Dust was not properly removed from the surface

to be painted.

• Paint material not sieved.

• Function of the painting facilities not optimum.

• Filter contaminated.

• Wearing unsuitable clothing.

Repair of damage:

• Single inclusions: after thorough hardening,

sand out using 1200 - 1500 grade paper and
repolish using a suitable silicone-free sanding
or painting paste.

• Large area contamination: sand and repaint.

Water marks

Ring shaped marks appearing on the paint surface.

Cause/damage pattern:

• Evaporation of water droplets on freshly painted

and not yet fully hardened paint finishes (mostly
only found on horizontal surfaces).

• Layer too thick.

• Drying time too short.

• Hardening faults or hardener no longer useable.

• Use of unsuitable thinners.

Repair of damage:

• Rub down only slight marks with sanding paper

grade P1000 - P1200 and then polish.

• For heavy marking, sand the surface matt, clean

with silicone remover and repaint.

Paint runs

Wave-like paint run tracks in top coat or in an
intermediate layer on vertical surfaces. Mostly in
the area of swage lines, seams or openings (there
they are paint runs, otherwise curtains).

Cause/damage pattern:

• Uneven paint application.

• The specified viscosity was not complied with.

• Use of unsuitable thinner materials.

• Air, material or room temperature too low.

• Layers too thick.

• Spray gun (nozzle) not perfect.

Repair of damage:

• After thorough drying, sand unevenness flat, if

necessary leave to dry afterwards.

• Small areas of damage can be equalised using

the paint plane, then sand, polish or repaint.

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Swirl marks

Three dimensional appearance in the paint surface
in the form of smears or blotches. This effect is
intensified in direct sunlight.

Cause/damage pattern:

• Polishing using polishing machine on paint

which has not yet hardened throughout.

• Polishing intervals too long or none at all.

• Pressure too high while polishing.

• Incorrect polishing material or polishing tool.

Repair of damage:

• Allow the paint to harden completely and then

polish.

• If the damage is irreversible, rub down and apply

new clear lacquer.

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Tools and Equipment for Paint Repairs

General work equipment

In the repair paint shop there is a range of painting
tools which make the work of the painter easier
and improve the quality of the repair paintwork.

Among these are small tools which are used for
the following work:

• Measuring beakers to measure and mix

various paint materials.

• Measuring rods with which the required

combination amounts of paint and primer filler
are gauged and mixed.

• Viscosity measuring beaker with a calibrated

opening of 4mm, used to set the correct paint
viscosity.

• Paint filter/paint sieve for filtering foreign

bodies out of mixed paint or primer. Care must
be taken that the correct filter is used for each
paint.

• Color sample plates onto which the mixed

paint is applied, and the shade is then compared
to that of the vehicle. Other aids which should
help the painter to find the correct shade are
color sample cards and color panels, which
are offered by many paint manufacturers.

• Dust bonding cloths which are impregnated

with a tacky resin and which pick up dust
particles particularly well. A surface to be
painted must be cleaned with a dust binding
cloth immediately before paint is applied.

• Compressed air guns are used to remove

sanding residues and to dry sanded surfaces.

Filler and spray guns

NOTE: Regular maintenance, cleaning after use
and careful handling of all individual parts of the
spray gun are essential for a high-quality paint
finish.

The spray gun is the most important implement in
the paint shop. Application of paint using the spray
gun can produce a layer with absolutely constant
thickness and a smooth paint surface.

Principle of operation

Description

Item

Air supply

Paint supply

Nozzle needle

Because of the construction design and with the
aid of compressed air, a spray-ready paint mixture
is dragged out of the container to the nozzle by the
venturi effect, and is applied to the surface being
worked.

When the trigger of the spray gun is pressed to the
first pressure point, only the compressed air
passage opens. If the trigger is pressed further,
the nozzle needle displaces and the air stream
drags paint with it at high speed. This produces a
spray mist consisting of micro-droplets of paint.

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Types of spray gun

Description

Item

Suction-beaker spray gun

Flow-beaker spray gun

In the flow-beaker spray gun, the paint container
is mounted above the spray gun. On the
suction-beaker spray gun, it is below.

Furthermore, spray guns are categorized by their
air pressure requirement into high and low pressure
guns.

High pressure guns have the disadvantage that
they exhibit high consumption of energy and
materials. The spray pressure they require is
between 1 - 6 bar.

Because of the high air pressure and the large
amount of air needed, the result is a powerful paint
mist formation (paint transfer rate approx. 35%).

Current practice is mainly to work with reduced
mist spray systems (RP and HVLP systems).

Reduced pressure (RP) guns are optimized high
pressure guns which have an input pressure at the
gun of approx. 2.5 bar and an atomization pressure
at the air cap of 1 - 2 bar. In practice this spray
technology is preferred for spraying clear lacquer
because of the finer atomization.

Low pressure guns have the advantage that they
exhibit minimal paint mist formation and because
of this the paint transfer rate rises to approx. 65%.
The spray pressure required in this case is between
1 - 5 bar. Nozzle sizes from 1 - 2.2 mm can be
used.

HVLP spray guns

Description

Item

Quantity control

Working pressure control

Spray pattern control

The high volume low pressure (HVLP) spray gun
is a high performance spray gun which forms a
soft, fine and homogenous spray pattern. The
atomization pressure at the air cap is 0.7 bar when
the input pressure at the gun is 2.0 bar.

The low atomization pressure of 0.7 bar together
with greatly reduced spray mist provide high
material ejection. The low nozzle internal pressure
minimizes rebound of the paint droplets from the
object and thus the proportion of overspray.

This spray technology has a very high application
efficiency. By matching the size of the nozzle, the
HVLP spray gun can be used for all repair painting
materials.

HVLP spray guns are often used in practice for the
application of water based paints.

Mini spray guns are often used for small, localized
touching-up work. Use of HVLP spray technology
and nozzle sizes of 0.3 - 1.2 mm permits very fine

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work, so that the area of the repair can be kept as
small as possible.

In order to ensure that a spray gun operates
efficiently for a long time, careful cleaning is
absolutely vital after use.

NOTE: During cleaning you must distinguish
between water based and solvent based materials.

Cleaning by hand:

• Empty the paint beaker immediately after use.

• Flush the gun with cleaner.

• Clean it inside and outside with a brush.

• Dismantle the gun to clean it thoroughly.

• Clean the air cap using a suitable brush.

• Use nozzle cleaning needles to clean bores and

nozzles.

A spray gun washing machine is recommended if
the painting work is highly intensive.

New types of paint processing systems are
replacing the conventional mixing beaker, filter and
spray gun flow beaker. This reduces the amount
of solvent required for cleaning and the amount of
routine waste which remains.

Paint preparation system (PPS)

Description

Item

Beaker

Color bag

With this system, which is suitable for both suction
and flow beaker spray guns, only one beaker is
required for mixing and painting.

A bag is inserted in the beaker, in which paint can
be mixed, processed and stored after use or
completely disposed of.

The small quantity of paint remaining in the gun is
removed using a minimum quantity of solvent from
the pipette bottle.

The amount of cleaner used is reduced because
only the spray gun needs to be cleaned.

Hand and machine sanding tools

Sanding is used to prepare a surface for application
of a paint layer, enabling it to adhere well. Sanding
materials have a great influence on the quality of
a repair paint finish. The correct sanding medium
must therefore be chosen for every material.

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