The large number of economic body and paint repairs the areas to
be coated in the meantime must be kept to the minimum necessary
compared with coating an entire part.
In addition, vehicles with multilayer paint applications
(Metallic coatings, mineral effect coatings and two-colour paint
applications) are becoming more widespread on the market.
In this connection the techniques used are blend-in painting,
touching-up and the painting of partial areas.
The blending system is used on metallic surfaces. The standard
systems (painting of individual parts) are used for plastic parts
(front and rear panelling) and interior surfaces (engine
compartment, rear floor) of the body.
Blending-in or touching-up should only be carried out if, after
a sample panel painting and additional shade correction, adequate
paint matching is not possible.
Blending-in or touching-up is essential on three-layer
paintwork.
For two-layer paintwork, apply the time allowances for Paint
stage 2, adjoining part.
For three-layer paint, the time allowances for paint stage 2,
adjoining part, must be used but an additional time supplement of
20% of the time allowances is applied (see TIS 2000, Time
allowances, Introduction Assembly B)
Blend-in painting (in general):
To ensure optimum adhesion of the base coat and clear coat,
pre-sand and spray 1 layer of bonding agent (mix component 666 with
colour mixing system or Basefix) onto the repaired part and
neighbouring part(s).
Touching-up (in general):
When repairing, for example, the body side, only the sanded
neighbouring exterior parts (quarter panel / roof frame extension)
should be sprayed with mix component 666 or Basefix.
The spraying technique for touching up a plain 1-coat
application uses touch-up thinners.
Painting partial areas (in general):
Build up damaged area with filler. Sand down as far as the
expected edge of the last spraying operation with unmixed touch-up
thinners, depending on the area of damage and its position on the
body.
Note: For sanding,
use equipment with grain size P2000 and fine sanding paste.
Brief Description of Blend-in Painting
Clean and sand damaged area. Apply putty, if necessary. Clean,
degrease, apply filler to damaged area. Sand filler.
Sand the entire part beyond the damaged area. Give a matt finish
to the adjoining part using sanding paste and sanding/matting pad
fine.
Mix bonding agent 666 or Basefix with 20% hydro-basecoat
activator / universal thinners. Apply one covering coat of this
mixture to the entire surface of the adjoining part.
1st layer:
Apply base paint on the damaged part and fade out on adjoining
part, allow to dry.
Dry the surfaces, do not blow-dry them. Polish area with tack
cloth
2nd and 3rd layer:
apply base paint. Apply paint fading out past the perimeter
zones of the first paint application. Allow to dry.
Apply 1 feathering coat of clear coat over both parts. Observe
drying time.
Apply one more coat of clear coat. Then allow to set and
dry.
Example: Fault in outer rear quarter panel. Blend-in paint
adjoining part (rear door).
Paint system
1.
New part (or damaged part)
2.
Apply bonding agent to repaired part/area and
adjoining part/area
3.
Apply base paint (to finish-sanded filler and
adjoining part)
4.
Fog zone 1/3
5.
Apply a thin layer of clear coat in the transition
area (optimum colour transition)
6.
To finish, spray the whole area with clear
coat
Brief Description of Touching-up
Clean and sand damaged area. Apply putty, if necessary. Clean,
degrease, sand filler.
Give a matt finish to the damaged zone - including adjoining
part - using sanding paste and sanding/matting pad fine.
Bonding agent 666 or Basefix with 20% hydro-base coat activator
/ universal thinners. Apply this mixture in 1 uninterrupted layer
over the whole part (adhesion for clear coat)
Apply 1 feathering coat of mixed clear coat over the repaired
zone – 1 feathering coat of mixed clear coat over the entire
surface. Note drying time.
Example: Fault in outer rear quarter panel of body. Touching-up
the part with clear coat.
Paint system
1.
New part (or damaged part)
2.
Apply bonding agent 666 or basefix to repaired and
adjoining part/surface
3.
Apply bonding agent 666 or base coat (to sanded
filler and adjoining part)
4.
Fog zone 1/3
5.
Apply clear coat (complete)
Brief description - painting partial areas
General:
Painting partial areas is a method of touching up in which a
transition is made between "old paint" and a repair area that is as
small as possible, using a new build-up of greatly thinned clear
coat. Lastly, in this transition area between the "old" and new
clear coat, there is a certain risk that cracks can appear during
polishing. On the other hand it is necessary to use this economic
method.
The decision to paint partial areas must be taken separately for
each case. We can offer suggestions based on the current painting
techniques and the usual types of damage.
View of body areas and surfaces.
1.
No partial painting in flat areas (up to height of
door pillar)
•
Bonnet
•
Car roof
•
Luggage compartment lid, tailgate
•
Door pillars
•
Upper side panel
2.
Only sensible on vertical areas (door pillar to
centre of doors)
•
Beads and protective strips of doors
•
Wings, exterior side panels as far as the rear
panelling connection
3.
Sensible in lower body area.
•
Under door area
•
Front / rear panelling
The structure of the coating can vary depending on the damage
and inspection.
Variants in preliminary work:
1.
With isolating primer
2.
with 2C HS multifiller
3.
with polyester universal putty
Prepare (e.g. 2C HS multifiller)
1.
Clean
2.
Sand (dry with eccentric) using P240 sanding
means
3.
Dry (5 minutes)
4.
Sand (dry with eccentric) using P400 sanding
means
5.
Clean
6.
Apply 2C HS multi-filler (2 layers with reduced air
pressure)
7.
Dry
8.
Sand (dry) P2000 sanding means
9.
Cleanly mask the area
10.
Clean
11.
Polish partial area (note area for touch-up
thinners)
Preparation (general)
1.
Clean
2.
Sand (dry with eccentric) using P 240 sanding
means
3.
Clean
4.
Sand (dry with eccentric) using P 400 sanding
means
5.
Clean
6.
Mask the vehicle
7.
Final sanding (dry) with sanding means P 2000 +
fine grinding past (Blend prep) until the last coat with unmixed
touch-up thinners is detected in the edge area with the vehicle
paint.
8.
Clean
Build up further after preparation:
1.
Spray water base coat (for example: Anest IVATA-400
spray gun)
2.
Spray 1st coat over the areas with filler (allow to
dry for 3 minutes).
3.
Apply 2nd full coat (allow to dry for 3
minutes)
4.
Spray with clear coat (VOC clear coat; water base
clear coat)
5.
Add touch-up thinners to the water base clear coat.
Spray area over edge of base coat.
6.
Spray a transition coat with pure touch-up thinners
as far as the prepared area of polishing
7.
Allow to set until the surface of the clear coat is
transparent again.
8.
Furnace-dry the painting
Subsequent work
Polish part areas
First of all work with a small unit and small polishing
disc.
Carry out finishing work with a large polishing disc.
Use ordinary sanding means available on the market, for
example:
Supplier:
Designation:
Festool
Titan 2 - P 3000
Platin 2 - P 2000 to P 4000
3M
Hocit - P 1500 to P 3000
Variants in preliminary work:
1 with isolating primer (spray can) for small surface
faults.
2 Area with 2C HS multifiller for larger areas of damage
(primer)
2a Area of sanding
3 with polyester universal putty for large areas of damage down
to the primer of the paint system. Further build-up after
preliminary work.
Apply water base coat
1 Spray layer over the filled area
2 Spray another coat
Apply clear coat spray with touch up thinners.
3 With pure touch-up thinners, spray around the polished area,
fading out with reduced air pressure.
Subsequent work
Polish part areas
Use small equipment for preliminary work
Carry out finishing work with a large polishing disc.
Use ordinary sanding means available on the market.
Mask the vehicle
According to the current state of the art, colour-adhering
painting films, free of heavy metals and usually made of
polyethylene mixtures, are used. The work of covering can be done
by one person, even for wide film. It is usually supplied in widths
of 90cm, 200cm and 400cm.
Advantages:
Considerably cheaper than masking paper
Heat resistant up to 100°C object temperature
Not microporous
Water-resistant, tear-resistant, free from fluff (no need to
cover again after wet sanding)
Protects the environment, contains no heavy metal
Examples: various covering with paint films on the Astra-H
Paint Systems
1-coat solid paint applications
2-coat solid paint applications
2-coat metallic paint applications
2-coat pearlescent paint applications
3-coat perlitic paintwork
Owing to the introduction of the blending system, the paint
systems are extended to include "blend-in painting" and
"touching-up". These systems are applied to achieve optimum colour
matching with solvent-based paint and preparation materials
specifically for 2-coat and 3-coat paint applications.
Paint Stages
Paint stages IIa and IIb correspond to paint stage II
Blend-in painting / touching-up are only to be used on two-coat
and three-coat paint applications. The previously familiar painting
stages I, II and III apply for painting individual parts.
Painting stage IIa applies to blending-in (blending system).
Painting stage II b applies to touching up (blending
system).
Paint stages IIa and IIb correspond to paint stage II
Blend-in painting / touching-up are only to be used on two-coat
and three-coat paint applications.
Painting partial areas
Bearing in mind the body design (edges, folds) it is possible to
delimit areas. Time allowances are already published for this work.
Painting of partial areas can be calculated in all paint stages
except paint stage I.
Time Allowances
The division of the preparatory operations is as follows:
Coarse putty operations and sealing operations come under sheet
metal operations in group A.
Fine putty operations come under the paint operations in group
B.
Paintable surfaces are to be produced in the sheet metal work
division (body workers, panel beaters).
The paint operations division (painters) takes over the work
from the sheet metal work division and completes the surface to be
painted.
This includes: at most 3 fine putty coats for screw parts, at
most 4 fine putty coats for welded parts.
Note: Spraying colour
samples for the painting of individual parts is included in the
set-up time.
Paint stages (for blending)
The time allowances for paint operations (main and combined) are
organised into the following stages:
Paint stage / blending
Metal parts (2-coat and 3-coat paint
applications)
II a
Blend-in painting
Paint bonding agent mixture or up to
approximately 50% into the adjoining part.
II b
Touching-up
Paint bonding agent mixture or Basefix into the
complete adjoining part.
Paint stages (for painting individual parts)
Paint stage / individual-part painting
Plastic parts
I
New part painting
Apply top coat to entire surface area
II
Surface painting
Apply filler to entire surface area
Apply top coat to entire surface area
III
Repair painting
Partially bond the area to be worked and apply
putty up to approx. 10% of the part area
Apply filler to entire surface area
Apply top coat to entire surface area
Create structure if required (structure
spray)
Production Painted Plastic Parts (Exterior)
The overview of factory-painted plastic parts is available in
the service instructions.
The top coat of factory installed plastic parts is applied with
a slightly thinner film of paint.
As a result, the stone-chip resistance of the paint system is
improved.
• Service:
For service paint repairs, thinner coats of paint must also be
sprayed.
It is no longer necessary to add plasticising additives to the
base paint .
Further information on painting techniques is given in the
dealer videos:
