Painting 2. Contents PAINTS AND PAINT SYSTEMS 3. FACTORY-FINISH PAINTING 4 Paint systems 4

Transcription

1 Contents PAINTS AND PAINT SYSTEMS 3 FACTORY-FINISH PAINTING 4 Paint systems 4 SPECIAL PAINTING 6 New colour 6 Cab and metal sheet parts 6 Painting 7 Painted chassis components 8 Wheels 8 Powder coated components 9 Components which are not powder coated 9 PLASTIC COMPONENTS 10 Plastic components on cab 10 Plastic parts on chassis 11 DECORATIVE STICKERS 12 2 Scania 1996

2 PAINTS AND PAINT SYSTEMS General The terms factory-finish painting and special painting are used in the following descriptions. Factory-finish painting is the painting carried out during Scania s production process. Special painting with a new colour means painting carried out in a paintshop according to customer requirements (if the colours are other than those available ex-works). Paint options The chassis frame and chassis components are factory-finish painted in production with a dark-grey top coat, Scania sub gray. The Scania colour guide, detailing the colours available from Scania can be ordered using part number In addition, vehicles can be factory-finish painted according to customer requirements with colours other than those mentioned above. The only exceptions are metallic and multiple paint combinations. Environmental considerations When choosing paint types, great emphasis has been placed on reduced environmental impact, both in the working environment and the environment at large. The paints used on factory-painted Scania vehicles contain no heavy metals. Recycling Painted PC/PBT plastics cannot be recycled to the same extent as unpainted plastics. Unpainted PC/ PBT plastic is fully recyclable. Choice of paint system Before starting the work of painting, it is generally necessary to consider the instructions and information from Scania together with the recommendations from the paint supplier. A test should always be made on a concealed surface if there is any doubt as to the compatibility of the paints. Many different makes and types of paint are available on the market. It is therefore important to follow the paint manufacturer s recommendations concerning what and how much thinners to use. Scania

3 FACTORY-FINISH PAINTING Paint systems Hot-dip galvanised steel 1 In order to improve the level of protection against corrosion in the cab, all Scania cabs are made from sheet steel which is hot-dip galvanised on both sides Cab and sheet metal parts Powder undercoat, epoxy polyester. Workpiece temperature about 180 C. Coat thickness µm. Top coat: alkyd melamine, oven-dried. Workpiece temperature about 145 C. Coat thickness µm. 5 1 Top coat µm 2 Power primer µm 3 Zinc, phosphate 2.0 µm 4 Hot-dip galvanizing 7.5 µm on each side 5 Sheet steel Plastic parts in cab (polyester) Primer, surfacer: polyester/melamine, oven-dried and air-dried. Workpiece temperature about 150 C. Coat thickness µm. Top coat: alkyd melamine, oven-dried. Workpiece temperature about 140 C. Coat thickness µm Top coat µm 2 Primer, surfacer µm 3 Plastic 4 Scania 1996

4 Chassis frame and chassis components Primer about 20 µm. Workpiece temperature about 125 C. Powder coating (polyester) about 100 µm. Workpiece temperature 180 C. Total coat thickness min. 100 µm Engine and gearbox Primer: Alkyd about 25 µm, air-dried. Top coat: Alkyd about 30 µm, air-dried. 1 Top coat, Powder about 100 µm 2 Primer about 20 µm 3 Steel Axles (Complete front and rear axles) Primer, alkyd/acrylate water-based µm. Top coat, alkyd/acrylate water-based µm. Total coat thickness about 80 µm. Propeller shafts Single coat two-part paint µm. Spare parts Spare parts are supplied painted in accordance with the appropriate system above. Axle parts normally only have an undercoat. Wheels Electro-coated about 20 µm or 2-part polyurethane paint. Scania

5 SPECIAL PAINTING New colour The special painting methods correspond to those used in production for factory-finish painting. IMPORTANT! Damage to the paintwork will cause corrosion. When touching-up, only the appropriate points need be observed. Anti-corrosive is most easily removed using white spirit or some other type of cleaning solvent. WARNING! White spirit is a solvent. Follow the safety instructions for protection against organic solvents. Cab and metal sheet parts Preparations 1 Cleaning: Clean the cab using water and detergent. Rinse well with clean water. 2 Mask the following parts: Headlamp housings, handles, position marker lights, rear-view mirrors and their holders, windscreen and windows and their weather strips, grille panel, boarding steps, pistons on the cab tilt cylinder and the pump. (There is otherwise a serious risk of leakage). Take care not to cut through the masking and damage paint layers and galvanised surfaces. Damage to the paintwork causes corrosion. 3 Rubbing down: Rub down the top coat until dull using fine grade abrasive paper (320-grain). Avoid rubbing through the paint and zinc coating below it. Rub down corners and edges by hand. IMPORTANT! Working on galvanised bodywork often damages the protective layer of zinc. The protection against corrosion must be re-established. Anti-corrosion oil and underbody compound are destroyed by welding. This protection must be re-established. Never view body repairs as complete until the metal is protected against corrosion, outside and inside. 6 Scania 1996

6 Painting 1 a: Sheet steel Use a suitable primer to touch-up any areas which have been rubbed through. (Avoid using primers with a high content of extenders). Ask your paint supplier to recommend a suitable primer. b: Galvanised sheet steel Use an epoxy primer to touch-up any areas which have been rubbed through. Ask your paint supplier to recommend a suitable primer. IMPORTANT! Observe the following when carrying out special painting or when repainting hot-dip galvanised parts: Do not blast. Always ask your paint supplier for advice about suitable paint systems. Avoid rubbing through to the metal. If you do rub through, use the correct type of primer. Paint which is not designed for galvanised steel will flake. 2 Filling: Consult your paint supplier. Some types of filler can be applied directly to steel and hot-dip galvanised surfaces. See Material specifications. 3 Clean the cab or components, removing all contaminants. Take extra care at edges. 4 For best results, paint using a 2-part paint such as polyurethane or acrylic. Ask your paint supplier if a different choice of paint would be more appropriate. It is also possible to use a synthetic top coat of airdried or assisted-dried type. Boundary lines When touching-up and painting after repairs, the cab s natural boundaries can be used for masking. This applies primarily to the windscreen frame, sides and roof joint. If several of the panels on the rear cab wall require touching-up, paint the entire wall. Scania

7 Painted chassis components 1 Wipe any visible grease from the axles, propeller shafts, unions and springs. Wash using degreaser. Rinse with water under high pressure, max. 50 C. 2 Rub down any corroded areas. Paint using a suitable anti-corrosion primer. 3 Paint using air-dried synthetic paint. Two-part paint can only be applied to the factory-finish paint if the earlier coat is thoroughly cured. If this is not observed, the paint will blister. The hardening time is affected by climatic conditions. Metallic paint cannot be applied directly to the factory-finish paint unless an undercoat is first applied. Consult your paint supplier. Wheels Always mask the mating surfaces on the wheels and nuts when painting. If the mating surfaces are painted, the paint will be worn off when the vehicle is driven. This means that the nuts will loosen and the wheels may come off. WARNING! Wheels may come loose if the mating surfaces for the wheel nuts are painted. Consult your paint supplier about a suitable paint for alloy wheels. 8 Scania 1996

8 Powder coated components Entire chassis or individual component It is necessary to use specially tested paint systems to achieve good adhesion to powder coatings. Good adhesion is achieved using 2-part akryl and polyurethane paints without preliminary rubbing. Start by testing the paint on a small area of the component. Cab and sheet metal parts 1 Thoroughly clean and degrease the surfaces. 2 Rub down any unevenness and other defects in the surface using fine abrasive paper. Rubbing down other surfaces also provides better adhesion. Do not use a grade of paper coarser than 360-grain. 3 If your rub down to the powder primer: Use a 2-part epoxy/polyurethane primer to ensure good adhesion. 4 Paint using the desired type of top coat. If the top coat is 2-part acrylic, it is not normally necessary to apply a primer. A surface which is rubbed down provides better adhesion. Epoxy should not be used as a top coat due to its sensitivity to UV light. (UV = ultraviolet.) In the case of single part air-dried paints, not even rubbing down the powder coating will guarantee sufficient adhesion. Follow the paint manufacturer s instructions concerning type and amount of thinners and drying times. Take care not to rub down to the bare metal. If you do this, a special primer must be used which provides good adhesion to zinc. Components which are not powder coated Axles After cleaning, axles can be painted with commonlyavailable paints using the Scania paint system. Test the adhesion of the paint on a small area. If necessary, consult your paint supplier. Scania

9 PLASTIC COMPONENTS Plastic components on cab With the exception of the sun visor, all external components on the cab (see drawing) are made from polyester plastic. The sun visor is made from PPO plastic. Painting Polyester plastic is suitable for painting and can also be oven painted (max. 130 C for 20 minutes). 1 Clean with water and detergent. Rinse with clean water. 2 Lightly rub down the paint with Scotch Bright A or S. As an alternative, abrasive paper can be used, but not coarser than 320-grain. It is very likely that plastic parts will become electrostatically charged when they are rubbed down. It is therefore important that they are rubbed down in a clean, dust-free environment. 3 Clean the surface 1). If you rub through to bare plastic, see points 4-5. If not, proceed to point 6. Carefully check the surface as there is a chance that the fibres in the plastic may have lifted. 4 Prime using a special primer of type Herberts Standoflex IK plastic filler +50% Standoflex thinner, Sikkens PC primer or similar. 5 Clean the surface. Test on a small area to see how the plastic reacts to the degreaser. Carefully wipe the surface using a rag cloth. 6 Paint using a synthetic top coat, either air-dried or assisted. Two-part paints such as polyurethane or acrylic are preferable. 1) If there is any risk of dust contamination, clean the surface with anti-static solution. An air-dried or assisted synthetic top coat can also be used. 10 Scania 1996

10 Plastic parts on chassis Side skirts, boarding casings, bumpers and mudguards (see drawing) are made from PC/PBT plastic. PC/PBT plastic, unlike the corresponding type of plastic in the 3 series, is easy to paint in the customer s livery. However, painting means that it cannot be recycled to the same extent as unpainted plastic. Unpainted PC/PBT plastic is fully recyclable. The preparation required is cleaning and possibly light rubbing down. Paint with one of the following primer types: Akzo Nobel Herberts BASF 2K PUR Clear-Coat Standox Glasurit The surface structure of PC/PBT items is uneven, requiring extra thorough cleaning. Use paints designed for flexible materials. Consult your paint supplier about suitable paint types. Scania

11 DECORATIVE STICKERS The decorative stickers are made from self-adhesive plastic film. The adhesive hardens and adhesion increases with time. If a part of the sticker or cab has been damaged, necessitating repair, it is not necessary to remove the entire sticker unless the colour match is too poor. Take care not to cut through the paint layer and galvanised layer. Damage to the paintwork causes corrosion. When fitting a new sticker, follow the instructions included with the sticker. Removing a whole sticker There are two methods for removing stickers: A Heat the sticker using a hot air gun of the same type as is used for repairing plastic cab components. Then proceed to points 1 and 2 below. B Use a special sticker remover such as 3M Sticker Remover 8907, which is sprayed over the entire sticker and dissolves the plastic film. Follow the supplier s instructions. Then proceed as below. 1 Remove the sticker using a rigid plastic scraper. 2 Remove any remaining adhesive or spray using a mixture of one part white spirit to two parts methylated spirit. Wipe using a lint-free cloth. Removing and repairing part of a sticker 1 Use tape to mask the edges of the section to be removed. 2 Treat the section to be removed as described in method A or B above. 3 Remove the section using a rigid plastic scraper. 4 Thoroughly clean the surface from which the sticker has been removed. Wipe with a lint-free cloth dampened with methylated spirit. 5 Cut a piece of sticker which easily covers the removed section. 6 Remove the masking and place the sticker over the repaired section. Follow the instructions included with the sticker. 12 Scania 1996