With the arrival cold and humidity in the winter season, it may sometimes be necessary to adapt certain repair processes at the workshop in order to optimise the workflow.
Despite the fact that modern paints used in the refinish sector have a high solids content in their composition, when painting with extreme cold and high humidity, atmospheric conditions will force the professional painter to adapt the paint preparation, application and drying processes.
Tips for optimising car repainting in winter
Regardless of the weather conditions, if you follow a set of guidelines and practical advice, you will obtain an excellent final result when painting a car in winter.
1. Use of special additives
A recommended practice to ensure a better performance of the paint in low temperature and high humidity environments will be the use of special additives.
An example of this type of product is SINNEK’s WA/6080 FAST DRY ADDITIVE, an easy-to-use and easy-to-apply additive that allows professionals to reduce the drying and hardening time of colour bases in this type of extreme environment, significantly increasing the profitability and productivity of each repair.
In addition, this type of product can be used to prevent masking tape marks from appearing during the striping process.
2. Follow the indications on handling and storage temperatures
Since body paint is a chemical product, its properties can vary if the room temperature is too low.
To guarantee a correct chemical reaction between the paint and its hardener, the ideal application temperature should be between 20º and 25ºC.
As for product storage, the room temperature should be between 15º and 30ºC. Below these temperatures, product properties may vary in terms of viscosity and sprayability.
In extremely cold environments, pay special attention to prevent water-based products from freezing. It is always advisable for the storage temperature to be above 5ºC.
3. Adjusting the paint viscosity
The cold increases paint viscosity. Pay special attention to the temperature and to the paint’s appearance when it is mixed.
If the product is too cold, it will have more viscosity, so the dilution shall be increased for a correct application.
Similarly, it is advisable not to dilute the mixture excessively as this will increase the risk of obtaining a low coverage repair.
4. Tempering the vehicle in the booth
Low temperatures and high humidity do not only affect the paint and its application, they also have a direct influence on the part’s temperature.
A good solution will be to put the vehicle or parts to be repaired in the booth before starting the repainting process.
The booth allows you to control the environmental temperature and humidity condition in addition to accelerating or reducing the application and drying processes.
5. Thermal shock
The surface temperature of a vehicle that has been exposed outdoors during a winter day will be too cold.
If the vehicle is put inside the booth without previously being tempered and then painted, you will risk a lack of adhesion.
This is due to a sudden change of temperature between the part and that of the booth along with any possible room humidity. This thermal shock causes the appearance of condensation on the surface, which can eventually lead to repainting problems.
This phenomenon will be more prevalent in high humidity environments. To prevent this, apply the product at least 3 degrees above the dew point temperature.
6. Correct surface preparation
In winter, it is common for cars to come to the workshop with traces of dirt on their surfaces such as grease, oil, dust or salt, which is used to prevent ice and snow on the road.
Correct washing and pre-cleaning of the surface will contribute to an optimum finish paint.
As an additional tip, salt residues can only be dissolved in water, so use soap and water for cleaning. Once removed, degrease the part thoroughly.
7. Follow the established evaporation times
Once the products and the vehicle are tempered, you can start the application process.
In winter, products take longer than normal to evaporate because of the cold or low temperatures.
This is why, in some cases it will be advisable to slightly increase the evaporation time with respect to the indications provided in the product’s technical data sheet, to ensure a correct drying and anchoring of the paint.
Follow these tips when applying paint in extremely cold conditions will provide you added safety and minimise the possible appearance of errors during the repainting process.
In addition, in places with low temperatures during most of the year, take the measures required to keep profitability and productivity rates for sheet metal and paint repairs.