Standox advises on finishing on plastics
Repairs on plastics can present refinishers with numerous problems. There are many different types of plastic in a variety of places on a vehicle – from the wheel arches to the bumpers and spoilers. Refinishers faced with problematic plastic repairs can turn to Standox for practical advice to get the best possible results.
“Plastics need painting for a variety of reasons,” says Jodie Henly, Standox brand specialist, “for aesthetic reasons, for instance, but, on a more practical level, painting will protect plastics against moisture, uv light and general aging. But it can be tricky. Everything from its condition – whether the parts are new, or if they’ve been repaired – to the type of plastics, with varying designs and functions, and even the conditions and resources available to the bodyshop, will make a difference. However, if refinishers follow some basic rules, there’s no reason why they can’t obtain excellent results.”
Before work can begin, the part to be refinished needs a thorough inspection to ascertain whether it’s old or new, or if it has been painted, primed or is untreated. Has it been damaged? Is it resistant to solvents? The risks of old plastic parts relate to their unknown history so utmost care must be taken to avoid mistakes when refinishing them.
Getting paint to adhere on plastics is the next issue. The release agents used to free plastic parts from the mould will also inhibit the paint coating from adhering to the plastic, so these must be removed before painting. There are three types of release agent – external, internal and release paints – and a different technique is used to remove each of them. The parts must be warmed and cleaned repeatedly; cleaning agents have to have evaporated entirely before further processing. This is potentially the most important part of the process as it will ensure maximum adhesion.
A perfect refinish on plastic components is the result of skilful workmanship, correct preparation and the exact choice of colour. Plastic add-on parts on modern cars are usually painted in the same colour as the car. In this case, the same colour can be used with the addition of a plasticiser.
Things becomes more complicated when add-on parts are coated in a different colour, which is often the case on older cars or with decorative parts of current models. Standox offers refinishers a full range of colour tools for precise colour matching, such as Genius – the spectrophotometer, Standowin software, and the Standohyd Colour Box, as well as an online formula search.
Standox has produced a detailed, illustrated Standothek guide entitled How to refinish plastics which fully covers every aspect of the subject. To download this and other Standothek guides, or to find out more about Standox, visit www.standox.co.uk.