Experienced refinishers know the problem, as winter approaches and temperatures drop, refinish preparation work needs to be adapted accordingly. Lower temperatures can render clear coats and hardeners more viscous, making them much harder to work with.
Although most of South Africa is blessed with mild winters, there are still areas that receive extreme cold. So how can you best prepare your paint room for the cooler season?
Tip 1: 20ºC is Ideal
Temperature plays a critical role in many chemical processes; refinishing is no exception. That’s why refinishers need to pay particular attention to it in the cold winter months.
“Axalta products are pretty robust and, up to a point, they are quite forgiving of environments that are not ideal. Nonetheless, body shops should ensure certain minimal conditions are met to make sure they achieve professional results, even in winter,” said Paul Polverino, national training manager. “When storing or working with VOC compliant clear coats, temperatures should not be allowed to drop below 20ºC. This simple precaution can ensure optimal viscosity and sprayability. It is imperative that water-based products be protected against frost.”
Tip 2: Don’t over-dilute cold paint
“If a paint product seems thicker than usual during mixing, check its temperature and viscosity. In most cases, the problem is usually that the paint is simply too cold,” said Polverino. Additional diluting of the product with extra thinner is not the optimal solution. Make sure the materials about to be used are at a room temperature of at least 20ºC. Climate controlled paint mix and storage rooms can be well worth the effort in colder areas.
Tip 3: Bring vehicles into the heated spraybooth
Temperature is not only relevant for paint products and components, but also for car bodies, which should not be allowed to get too cold. If they do, a fine moisture film can develop on the surface as the vehicle warms up. This can create problems with the flow, surface wetting and adhesion of the fresh paint and can lead to long term defects such as blistering. “This kind of moisture layer can make a superior result almost impossible to achieve. Allow the vehicle to stand in the heated spray booth for some time before starting work,” said Polverino.
Tip 4: Don’t “over-compensate” with a high spraying temperature
Just because it’s cold outside doesn’t mean we have to reach for the fastest hardener available. If your spray booth is running between 20-25ºC and has a quality bake cycle reaching recommended metal temperatures, then conditions are normal (inside the booth). Therefore, your hardener and thinner choice should be selected based on the size of the job and your spray booth’s conditions. Note that problems can occur if spraying is carried out in higher temperatures, particularly if combined with the wrong hardener choice.