Equipment and requirements
Paint Professional
When applying waterborne coatings, the first consideration should be equipment. Waterborne coatings can be applied with all of the usual application equipment, however it is important to keep the equipment and parts to be painted very clean. Molded parts such as bars and side mirrors can carry residual mould release agents while stamped parts (commonly steel) can retain oils, and plastic parts can attract dust from:
- Reduced solvent fumes means cleaner air and a healthier work environment.
- Waterborne paints are nonflammable; therefore, they reduce the risk of fire.
- Basecoat colour match, metallic control and the ability to blend, meet or exceed that of solvent-borne basecoats.
- Waterborne paint spilled can be simply washed off with soap and water.
- Waterborne products can be applied with either conventional or high volume, low pressure (HVLP) guns.
- Air Movement To accelerate the dry time of waterborne coatings, an air movement system should be available in the spray booth, commonly called ?air diffusers?. After the basecoat is applied, the unit is turned on for several minutes to flash off between coats. A unit can be equipped with a series of specific nozzles that direct a high volume of air at the surface of the vehicle in order to help evaporate the water from the basecoat.
- Heat Conventional or infrared heat lamps can be used to decrease the drying time of waterborne primers or basecoats, although only in conjunction with air movement systems. When used alone, heat systems are not as effective, because they create a layer of water-saturated air just above the surface of the refinished area. Unless this water-saturated layer is removed by air movement, the effectiveness of heat application is reduced and drying is slowed down.
- Cleanup and Disposal Spray guns and equipment should be cleaned with water and/or waterborne cleaners as specified by the supplier, in a separate system. A separate waste collection system dedicated to waterborne wastes should be used as solvent and waterborne wastes do not mix. There is no problem disposing of waterborne wastes as long as it is executed through a fully licensed waste remover contractor.
- Health and Safety Equipment Waterborne products can offer a number of health and safety benefits to the paint refinish industry, however, it is recommended that paint technicians use the personal protective equipment specified in suppliers' material safety data sheets. It is important that the paint shop technician read all instructions and cautions before using waterborne (or any other) paint product.
- Spray booths In order to ensure the highest quality of work with any painting system, including waterborne, a spray booth should be used. The most suitable type of spray booths for waterborne application is full down-draft spray booth. As with solvent-borne products, waterborne requires specific conditions and lighting, as well as climate-controlled spray booths to achieve the best performance.
- Booth Filters Paper and cardboard type filters can break down as they filter water base paint particles from vented air, and quickly become matted and block essential air flow. It is important to research all equipment necessary for water base coatings.
Are We Ready For Waterborne?
When waterborne products were introduced to the refinish market in the early 90s, these ?traditional? waterborne products had an unstable shelf life, experienced pigment agglomeration and were prone to contamination. Paint shops that experimented with these earlier waterborne products share negative views about them. Traditional waterborne coatings required a DIN cup and a stopwatch to achieve viscosity, dried slowly, and some shops experienced complications in blending. The concern with waterborne systems was a drop in productivity. With technical innovation, the premium waterborne systems have overcome this. These premium systems have a defined mixing ratio (like solvent borne systems), have the same five year shelf life as solvent borne mixing bases. Also, the drying time of premium waterborne systems is now comparable to solvent borne systems and the application characteristics, including blending and coverage, are now better than solvent borne products. In general, waterborne products require some new equipment and a comprehensive training program to be successfully introduced into a paint shop. As most countries, including Australia, strive to improve air quality, the use of alternatives such as waterborne coatings will increase. The benefits can be substantial, but waterborne products may not be the answer for everyone. If you are considering waterborne products for your business, BASF Coatings can answer your questions.
You can contact BASF Coatings on (02) 87870111.