Waterborne Automotive Paints - A Complete Guide
Whether you are an auto body shop, manufacturer, or wood worker you may see that companies are moving to waterborne paints more and more often. You also may have heard horror stories associated with waterborne automotive paints where the finish doesn’t adhere and comes off while a driver is driving or that it is impossible to get the finishes to come out with the same quality and clarity of solvent based paints. While some of these stories have elements of truth, some do not. This guide will cover waterborne automotive paints, how to spray them, why to consider them, and frequent challenges of using them.
Pros of Waterborne Automotive Paints
Waterborne automotive paints offer a variety of benefits. The biggest benefit of waterborne automotive paint is that it doesn’t cause as much harm to the environment. Compared to solvent based automotive paints, water borne automotive paints are composed of about 10 percent solvents compared to around 74% for waterborne automotive paints. States usually require a license based on the volume of VOC’s that you produce. Using a water borne paint will reduce your VOC’s that you produce and depending on your area may be required. Additionally, waterborne paints typically have higher coverage than solvent based paints (due to higher solids content) which lets them cover a car more efficiently and spend less time applying paint. Finally, waterborne paint is a bit more readily available because many automotive companies are now required to use water borne paints which means that it can be found at the majority of auto body paint supply stores.
Cons of Waterborne Automotive Paints
While waterborne paints offer a variety of benefits they also can present unique challenges. First, waterborne paints require greater control of the application environment like the paint booth temperature, moisture levels, and quality of compressed air you have in your shop. Failure to keep temperature & humidity within the recommended range can lead to problems like slow dry times allowing for increased risk of contaminations of your paint finish or changes in production. Additionally, as a general rule, waterborne automotive paints will typically not be quite as durable as a solvent based alternative. Additionally, due to higher solids content, waterborne paints take a little more consideration to get them to spray out well and a more expensive spray gun.
Specific Tips to Spray Waterborne Paints
If you have considered the pros and cons of automotive waterborne paints and have decided that you will be using a waterborne automotive paint the next thing to consider is how to work with waterborne automotive paints.
Remember you still have solvents in waterborne automotive paint
The first thing to remember is that just the base coat typically consists of a full waterborne product while the clear coats are still solvent based. To spray water based paints you want equipment to have stainless steel fluid passages or other material that will resist corrosion. While the majority of gravity feed spray guns will come with stainless fluid passages, if you will be using a pressure pot a standard pressure pot is usually carbon steel. Ensuring that your equipment is stainless steel will prevent it from rusting or prematurely wearing.
WaterBorne Automotive Paints Dry Differently Than Solvent Borne Paints
In addition to having stainless steel for your spray gun and/or pressure pot, you may want to consider a solution to speed up curing times with water borne automotive paints. Unlike solvent based paints, cure time is accelerated by turbulent air movement across the vehicles surface which can be accomplished by air curing towers. Solvent borne paints are typically accelerated by temperature elevation. Typically you still want temperature control with water borne paints as temperature control will prevent issues with application as water borne coatings tend not to do as well adhering to cold surfaces along with other challenges that can result from poor environmental control.
Waterborne Automotive Paint May Look different initially then the final dry color
Waterborne automotive paints colors can change as they dry which can take a bit of getting used to if your use to determining the way the final finish appears based on the initial coat sprayed. This drying effect can also require learning when you are doing touch up work with automotive waterborne coatings.
Ultimately making the switch to waterborne automotive paint or using automotive waterborne paint can take a bit of adjustment if your use to primarily using solvent based automotive paints. By understanding the unique challenges you can better prepare to use the automotive paint. If you need tips on adjusting your spray gun check out this guide with photos that show what a good finish spray pattern will look like.