PAINTING
Cellulosics or Acrylics: make your choice!
The maintenance or restoration of an old vehicle requires a lot of attention, care and precision.
Antique cars have much more fragile bodies than contemporary cars. At the time, rocker panels attacked by rust and road salting were common after three harsh winters. Because the paintwork of the time was not as good as it is today, the fenders and doors were prime targets for corrosion. The rust devoured the sheet metal, and without the timely intervention of a bodybuilder, a hole would end up forming.
Some collectors prefer cellulosic paints (cellulose-based, requiring solvents such as acetone) to acrylic paints (water-soluble paints). The latter are nowadays used by coachbuilders for their covering power and their thickness obtained by polishing. Application of a cellulosic paint requires more product and elbow grease than a contemporary paint.
As the original baths no longer exist, the painters are obliged to recover their composition.
From a sample, the spectrometer precisely determines the mixture to be made. It thus makes it possible to recreate the mixture with a paint that is more resistant to UV and corrosion. Original paint or new tints are possible, although purists often prefer to restore their cars to their original colour. Original restorations ensure that the value of the vehicle is maintained.
Several options are possible for the application of the paint according to the part to be treated:
Hand Spray Painting
The technique most commonly used in the restoration of old vehicles.
For maximum precision, both for simple touch-ups to integral paintings.
Electrostatic paint
Suitable for parts that can be treated separately: doors, bonnet, parts and accessories for motorcycles, etc.
Electrostatic painting: painting process using a specific gun charged with static electricity.
The metal part to be painted is positively charged while the paint is negatively charged.
Negative particles of paint are then propelled by means of a spray gun. The positively charged metal automatically attracts them like a magnet.
For this reason, electrostatic painting has many advantages:
- It remains as a reliable way to quickly cover a metal surface.
- It allows you to paint very complex shapes.
- It allows a much faster drying.
- It offers a particularly uniform finish for excellent tension after drying.
- It prevents drips, marks and unaesthetic traces.
Powder-coating
Powder coating processes are non-polluting methods of application used in industry to coat and protect metal substrates.
The paint is present in the form of a thermosetting powder resin. The advantage of these processes is the absence of solvents, which is of economic, environmental, hygienic and occupational safety interest: reduced fire risk, no respiratory exposure to solvents.
In the case of powder coating, the paint is sprayed using an electrostatic gun, which carries a positive charge.
The paint takes form of a very fine cold powder that is charged (positively) by an electric field.
The conductive part to be painted carries an opposite (negative) charge; the powder, attracted by the Coulomb force, thus adheres temporarily to the part.
Then the part is passed through the oven, which allows melting and polymerization of the thermosetting powder.
This technique is suitable for parts with complex shapes and large volumes and is widely used in the automotive sector and for the treatment of metal furniture parts.
Powder coating is a resistant surface coating with a particularly glossy appearance.
The sprayed powder is a polyester base with a perfect resistance to UV rays.
For perfect tension, the powder is applied hot. Polymerisation is carried out in a tunnel or in an oven for larger parts.
Parts that are subject to chipping, such as rims and suspension elements, are powder-coated. The splash resistance is excellent and the corrosion protection is of good quality.
The aluminium rims can be microblasted and protected with a colourless powder coating.
Motorcycle frames, swingarms and wheels are originally powder-coated.
