DuPont has issued another series of useful hints and tips for bodyshops, this time concentrating on how to avoid common paint defects.

DuPont says that defects are costly and time-consuming for bodyshops to rectify, so it is essential to avoid them happening in the first place. The company says that there are seven main areas in the refinishing process where pitfalls can trip up refinishers and cause paint defects.

Cleaning
The first step of the repair process is arguably the most important in the perfect repair. It is at this stage where many paint defects are born, including blistering, lifting and peeling. Thankfully, preventing these defects is simple: proper substrate cleaning. Refinishers must ensure the surface is cleaned and de-greased completely with the right products. 

Surface preparation
A multitude of defects can be triggered if the surface of the repair is not prepared properly. Areas here to watch out for include not sanding the repair area enough or using the incorrect grade of sand-paper. Similarly not completing the undercoat process correctly or not allowing the undercoat to dry thoroughly will lead to many common paint defects.

Preparation of product
Once refinishers are in the mixing room there are many pitfalls waiting for them. It is essential that only recommended ancillary products, such as thinners, additives and activators, are used, using non-recommended ones is a sure-fire recipe for defects occurring later. Refinishers should also refer to instructions on technical data sheets and label and follow carefully.

Application
Training is key for this stage of the repair, and there are many obvious mistakes that can happen in the spraybooth that can lead to costly defects in the finish. The basic spraygun set-up is the first thing to check. Once the application is underway, refinishers must ensure they position themselves the correct distance from the panel, apply the right number of coats, and utilise the relevant spraying technique for the job. Coats that are too thick, that have do not have enough film build or that have not been allowed to flash-off for the correct amount of time will cause defects.

Drying
This stage seems straightforward enough, but it is one where defects can occur.  The temperature and time of the baking cycle must be calculated according to the technical data sheet instructions. It is also important to respect flash-off times after the last coat was applied.

Equipment
Even if all the steps in the process are carried out flawlessly, defects can still appear. Bodyshop equipment is often the culprit, so it is very important it is maintained regularly and working perfectly. Items that can be particularly problematic include filters, pipelines and sprayguns.

Environment
In addition to the equipment posing problems, the general environment also plays a role in causing paint defects. The humidity level is a key point that refinishers should be aware of, as well as the bodyshop temperature.

Anthony Cashel, Brand Marketing Coordinator, DuPont Refinish UK and Ireland says, “The bodyshop is littered with pitfalls for the refinisher. In order to ensure the perfect repair every time coupled with maximum productivity, refinishers must be aware of the areas that can cause paint defects. To stay up-to-date, training is key, which is why we suggest regular courses at the Refinish Training Centre in Stevenage.”

For more information on courses, please visit www.dupontrefinish.co.uk.