3.1 - Paint Finishes For Porsche Vehicles
3.1 Paint Finishes For Porsche Vehicles
3.1.1 Series paint finishes - paint build-up
Series paint finishes are paint finishes carried out by the manufacturer in series production. Painting work, which is carried out by the manufacturer during reworking, involves repeat paint finishes, also regarded therefore as series paint finishes.
Series paint finishes are composed of various layers, depending on whether they are solid, metallic, solid double-layer or pearl-effect paint finishes.
3.1.1.1 Series paint finish process of galvanized bodies
The Porsche series paint finish process consists of 23 operations:
1. Cleaning and degreasing the body's outer shell
2. Cold-rinsing the body with service water
3. Rinsing the body again with deionized water
4. Electro-dipbath (KTL = cathodic dipbath)
5. Cold-rinsing the body with service water
6. Rinsing the body again with deionized water
7. Stoving the electro-dipbath
8. Sealing the body with PVC
9. Spraying PVC undersealing on the entire vehicle floor, the wheel housings, front apron and side member panels with a layer thickness of 0.6 to 1.0 mm.
10. Cleaning PVC spray dust off the body
11. Stoving the undersealing and the seam seal
12. Polishing the stoved electro-dipbath
13. Inserting sealing insulating mats into the body
14. Cleaning all dust off the body
15. Spraying the filler (in white, light gray or dark green, depending on the color of the top coat paint)
16. Stoving the filler
17. Washing the body off with deionized water
18. Drying the body in a hot-air oven and clean off all dust
19. Spraying the top coat paint
20. Flash off of top coat paint
21. Spraying on clear lacquer
22. Stoving clear coat
23. Painting the various passenger compartment parts black
3.1.1.2 Structure of solid paint finish
Layer thickness of solid paint finish approx. 120 (mu)m
3.1.1.3 Build-up of metallic and solid double-layer paint finish
Layer thickness of metallic and solid double-layer paint finish: approx. 120 to 140 (mu)m
3.1.1.4 Structure of pearl-effect paint finish
Layer thickness of pearl-effect paint finish: approx. 120 to 140 (mu)m
3.1.1.5 Series paint finish process of fiber-reinforced bodies
The Porsche series paint finish process consists of 18 operations:
1. Cleaning and degreasing the body's outer shell
2. Sanding outer shell of the body
3. Cleaning all dust off the body
4. Spraying the filler
5. Stoving the filler
6. Sanding the stoved filler
7. Spraying PVC undersealing on front apron and side member panels with a layer thickness of 0.6 to 1.0 mm.
8. Cleaning PVC spray dust off the body
9. Spraying the filler (in red, yellow, black, light gray or dark gray, depending on the color of the top coat paint)
10. Stoving the filler
11. Sanding the stoved filler
12. Washing the body off with deionized water
13. Drying the body in a hot-air oven and clean off all dust
14. Spraying the top coat paint
15. Flash off of top coat paint
16. Spraying on clear lacquer
17. Stoving clear coat
18. Painting the various passenger compartment parts black
3.1.1.6 Build-up of carbon-look paint finish
Layer thickness of carbon-look paint finish: approx. 60 (mu)m
3.1.1.7 Build-up of metallic and solid double-layer paint finish
Layer thickness of metallic and solid double-layer paint finish: approx. 200 (mu)m
3.1.1.8 Build-up of metallic and solid double-layer paint finish with stone chip protection
Layer thickness of metallic and solid double-layer paint finish with stone chip protection: approx. 270-300 (mu)m
3.1.2 Primer for spare body parts
The body parts, made of galvanized sheet steel panels for replacement needs, are coated with various priming materials at Porsche.
It is important to differentiate between primer that can be used in build-up, and primer that cannot be used in build-up.
3.1.2.1 Primers that can and cannot be used in build-up
Primers that can be used in build-up include:
- Primers applied using KTL (cathodic dipbath)
- Primers with epoxy thick-coat filler
There are various ways to identify a prime coat which can be used in build-up.
NOTE:
- In the case of a build-up primer, the filler and topcoat paint can be applied immediately after the primer is sanded.
- If the non-build-up primer is not completely removed, detachment (adhesion problems) of the entire paint build-up will result. The non-build-up primer must therefore be removed completely using solvents (thinner).
3.1.3 Water-based paint technology at Porsche
The conventional paints and paint materials containing solvents are gradually being replaced by water-based paints.
The use of water-based paints offers welcome advantages for the environment and the health of the sprayer thanks to significantly lower emission values.
3.1.3.1 Legislation
Another reason for replacing conventional paints with water-based paints is legislation. The legislation defines the maximum permissible values for emissions, nitric oxides and volatile organic compounds (VOC), which result from the volatile solvents used during painting, for vehicle manufacturers. This involves not only reducing emissions, however, but also preventing waste.
3.1.3.2 Implementation for Porsche production paint finishes
Huge emphasis is placed on the environment and environmental issues at Porsche. Given this high level of environmental awareness, water-based paints have been used in production paint finishes at Porsche since 1991. The welcome turn towards water-based paint technology should also extend to the repair sector.
Solvent emission during the conventional paint build-up of a complete paint finish (filler, topcoat paint, clear lacquer) is around 5.7 kg. When water-based paints are used, however, the solvent emission is reduced by 37% - which is 1.4 kg less damage to the environment.
Furthermore, waterborne filler has been used for paint build-up at Porsche since 1990. This has reduced solvent emissions by a total of 61%. That represents 3.5 kg less solvent per complete paint finish.
Essentially, the water-based paint finish at Porsche is carried out using the double-layer process, i.e. the layering consists of:
- water-based paint and
- clear lacquer
3.1.3.3 Repair sector
In view of these facts, the continuation of the well-supported approach towards the environment involves extending the water-based technology to the repair sector. The use of solvents has proven effects on:
- the environment
- the operating environment
- the work place
- the health of all individuals involved in repair painting
Following a six-month pilot project, during which the use and handling of water-based paints were field-tested and optimized for workshop use at the Porsche Center in Essen, the pilot phase ended with the world-wide release for the use of this pioneering technology for repair painting on Porsche vehicles.
The solvent emission during the conventional paint build-up of a complete paint finish, i.e. filler, topcoat paint and clear lacquer, is around 5.7 kg. Replacing conventional topcoat paints containing solvents with water-based paints reduces the solvent emission by 37%, which is 1.4 kg less damage to the environment. Conventional filler and clear lacquer are still used here.
If waterborne filler, which has been part of the Porsche repair material system since 1990, is still used for this paint build-up, the solvent emission is reduced by a total of 61%, which is 3.5 kg less solvent per complete vehicle.
3.1.3.4 Environmental protection
The advantages of this new technology clearly lie in the massive reduction in solvent emission. Compared with the conventional metallic paint system, which contains approx. 83% organic solvents, the corresponding water-based system only needs 10% organic solvents.
When cleaning the working devices, the use of solvent is even reduced by 100% because with this system only water is used for cleaning.
The waste disposal quantity is another environmental issue. A special coagulation agent is used to separate the solid waste in the paint from the water, thereby reducing the volume of residual substances to be disposed of to at least 10%.
More specifically, this means that:
- The dirty water from cleaning the equipment can be separated into water parts and paint parts using the coagulation agent, i.e. only the 10% residual quantity (paint parts) must be disposed of.
- The residual quantity can be halved again using further heat-assisted drying (forced evaporation) i.e. 5% must be disposed of as solid waste.
- The separate, filtered residual water can be reused as a cleaning agent, or may be introduced into the operating waste water, depending on local authority provisions.
3.1.3.5 Processing
An important advantage for paint finishing is that the paint systems for production paint finishes and repair paint finishes have essentially been standardized. The paint shop is faced with the problem of repairing increasingly shiny and sophisticated color shades in vehicle paint finishes. This means that it must be possible to reproduce the original condition of the paint finish under workshop conditions, i.e. the original condition can be restored through the craftsmanship of the sprayer and the average workshop employee. This is particularly important when it comes to restoring the look in the sense of matching color shades.
It is precisely in this area that water-based paint presents immediately detectable advantages for the repair paint sprayer through its color shade accuracy and spray reliability. Furthermore, this water-based paint can be used for all repair paint finishes, irrespective of whether the old paint finishes are conventional or water-based.
The blending technique that has since been used, i.e. blending-spray/spot painting adjacent parts in order to equalize color shade differences between old or original paint finishes and repair paint finishes, is also guaranteed here. The differences in the blending technique when water-based paints are used include the fact that no additional blending spray thinner is needed, the technique works without misting, and pre-painting with thinned clear lacquer is not required.
3.1.3.6 Qualification
The application of water-based paints does not require any great changes in procedures and spraying habits if the sprayer is experienced in handling HVLP spray guns.
Generally, a two-day on-site training course, i.e. in the paint shop, is sufficient to ensure independent and safe use of the new technology.
3.1.3.7 Investment
Apart from a special HVLP spray gun (HVLP = High Volume Low Pressure), which reduces mist during paint jobs and saves money on materials, no further investments are needed for implementing the water-based technology since this technology can be used in existing plants.
3.1.3.8 Summary
The use of the water-based technology, i.e.
- cleaning agents containing reduced solvents
- water-based colors and mixing base
- water for cleaning equipment
- coagulation agent allows
- reduced solvent consumption and solvent costs
- reduced material requirements
- savings on waste disposal costs
- a safe and systematic introduction into water-based repair technology in order to comply with the requirements of the automobile industry and future legal specifications
- an active contribution to environmental protection and to improving health conditions in the workplace
3.1.3.9 Identifying water-based paints
Water-based technology for topcoat paints is currently used along with conventional solvent-based paints.
Given this, a particular color can have the same color name, but may be available both as a water-based paint and a conventional paint.
The paint type applied during production may be determined by referring to the paint code on the paint data plate on the vehicle or by looking through the "Paint system" column in the corresponding color table ( -> 3.3. "Paint colors for Porsche vehicles") 3.3 - Paint Colors For Porsche Vehicles.
Explanation of paint system codes
U = solid
M = metallic effect
P = pearl-color effect
W = water-base paint
1 = single-layer process
2 = double-layer process
A further aid to recognition is the knowledge of the range of vehicle paint finishes that are not water-based.
All color shades in the solid single-layer range are not water-based vehicle paint finishes.
3.1.3.10 Respraying water-based production paint finishes
Water-based production paint finishes (original paint finishes) can essentially be resprayed using repair paint finishes in two different ways:
- Repair paint finishes with conventional repair paints that contain solvents and whose color shades have been matched to the original paint finish.
- Repair paint finishes with water-based paints whose color shades have been matched to the original paint finish. This is the preferred approach. The reasons for this and the advantages of this system are described in detail in -> 3.1.3 "Water-based paint technology at Porsche".
The basic requirement for a successful repair paint finish - irrespective of the repair paint system to be used - is that the correct repair paint, i.e. the repair paint that corresponds to the paint code on the paint data plate, is used.
There are no processing differences involved in respraying water-based production paint finishes (original paint finishes) using repair paint finishes.
NOTE: The use of water-based paints for repair paint finishes does not depend on the paint system used for production paint finishes. Water-based paints from the repair paint system can be used both for repair paint finishes for a conventional production paint finish as well as for repair paint finishes for a water-based production paint finish.
3.2 - Ordering Paint - Paint Data Plate