Teknos Winter Painting Information
Winter months can be a challenging time for manufacturers of joinery products. Almost 80% of problems related to factory finished joinery arise from items that are manufactured and supplied during this time of the year, from December to March. The reason for this is largely due to the low temperatures and high humidity levels that are typically present during winter. These conditions can wreak havoc on the manufacturing process, causing problems such as poor adhesion, cracking, and warping of the finished product.
To mitigate these issues, manufacturers can take several steps. One of the most effective is to control the environment in which the joinery products are manufactured and stored. This might involve investing in climate-controlled facilities or using heating and dehumidifying equipment to maintain optimal conditions. Additionally, manufacturers can take steps to ensure that raw materials are properly acclimatized before they are used, and that finished products are stored and transported in a way that minimizes exposure to extreme temperatures and moisture. By taking these and other measures, manufacturers can help to ensure that their joinery products are of the highest quality and will provide customers with many years of trouble-free use.
Modern coating systems have come a long way from traditional methods of application. These days, they undergo a two-stage drying and curing process. The first stage is called “coalescence”, which involves removing water and solvent from the wet film. This process results in the film becoming dry to the touch, although not all of the water has evaporated at this stage. This is a critical stage in the overall coating process as it provides the foundation for the second stage of drying and curing. It is important to note that the length of time required for coalescence varies depending on the type of coating used and the environmental conditions during application.
Dimensional change is a function of species and grade, but broadly timber dimensions vary by about 1% for every 3% change in moisture content. In winter, it is not untypical for joinery to leave the factory at around 10% moisture content, then rapidly condition to 18-20% on site, resulting in dimensional changes of 3–4%, causing joints to open and moisture to penetrate unprotected end grain and rebates.
Practical Steps to take in Factory
In a factory setting, achieving full coalescence of each coat of paint before the joinery is shipped is crucial in avoiding complaints. Fortunately, there are a few practical steps that you can take to ensure that this happens.
Firstly, it’s important to keep the paint in a heated store before use and never leave paint cans on a cold concrete floor. This helps to maintain the paint’s optimal consistency.
Secondly, it’s important to follow the film thickness specification. Over-application of paint is wasteful and slows down the drying process.
Thirdly, try to maintain a warm temperature of 15-20°C in the drying area, using a background heater or ducted, filtered, warm workshop air. This helps to create the ideal conditions for the paint to dry properly.
Fourthly, avoid switching off heat or air circulation fans overnight. In cool, still air, very little drying will take place. 
Fifthly, avoid trying to accelerate drying by blasting hot air at joinery items. This will speed up surface drying, but trap moisture in the film and slow down the coalescence process.
Lastly, delay wrapping finished joinery for as long as possible. Wrapping and storage in an unheated dispatch area will slow or stop moisture release from the film, preventing full coalescence. By following these simple steps, you can ensure that your joinery items are of the highest quality and avoid any unnecessary complaints.