Water Water (Almost) Everywhere

The use of waterborne paint is not yet universal, but more and more body shops are switching over. Here’s how to get started if you decide that waterborne is right for you.

As much as the quality of automotive paint has improved over the years, the nagging problems have always been those volatile organic compounds (VOCs) that pollute the environment, cause breathing problems in the shop and present difficult disposal problems. The answer to all these problems is waterborne paint.

If you want to convert to such a system in order to be environmentally noble, or if you have to in order to comply with VOC regulations, you might be wondering how that conversion takes place. Can you use the same paint guns? What are the drying times? What is involved with clean up? We’ll attempt to answer those, and other, common questions about switching to waterborne paint. But first, let’s review some background information.

What is Waterborne Paint?

Paint has four major components: (1) pigment, (2) binders, (3) solvents and (4) additives. The pigment is the color, the binder holds the pigment particles together and the additives modify the performance and characteristics of the paint. Finally, the solvent is the liquid solution that carries the pigment and binders in order for the paint to be sprayed. This is the nasty stuff, as solvents are petroleum based products. As the paint dries, these solvents are released into the air.

Waterborne paint is the latex paint of the automotive refinishing business. As its name implies, it is water-based, using water to carry the pigment and binder. This type of paint dries through the evaporation of water. Because it uses water, there are significantly fewer VOCs.

As you can imagine, waterborne paints were developed to meet stricter air pollution guidelines. Such laws were enacted in Europe back in the nineties, so all the major paint manufacturers have experience making this type of paint. Now these laws are being enacted in North America, specifically in Canada and southern California.

In the 10,000+ square miles that encompasses this part of the country, there are 16 million people and nearly 20 percent of all the auto body shops in the United States. And while automobiles are still the number one source of air pollutants, paints and solvents, such as those that originate in body shops, contribute about 12 percent to the total. Now you can see the need for waterborne paints.

In other parts of the country, many shop owners want to be more environmentally responsible. Using waterborne paints provides that opportunity. And with the environmental mood of the country, these air pollution regulations are sure to spread from the West Coast, so you’ll probably end up using waterborne paints at some point in the future.

Characteristics of Waterborne Paint

First of all, due to the use of water, waterborne paint is pretty much odorless. Also, unlike lacquer, that must be thinned, and enamel, which must be reduced, waterborne paint is pre-mixed. That means it’s ready to spray right out of the can. If it needs to be reduced, distilled water can be used to make it thinner and more soluble.

Waterborne paints handle, tint and spray differently than solvent-based paints; however, you shouldn’t be discouraged if you are going to make the switch. Water-based resins tend to be clear; therefore, the intensity and brightness of the color is high. As a result, color matching an OEM waterborne finish can be achieved with very acceptable results.

Water-based primers have been used for many years to correct paint lifting problems. These primers are an excellent barrier coat and dry to a hard, rock-like finish. Also, existing lacquer and enamel paints will not react with waterborne primers.

Here’s another significant point that can be made for waterborne paint: This type of paint in nonflammable, so the risk of fire in your body shop is reduced. Along with this might come lower insurance rates.

Making the Switch to Waterborne Paint

Regardless of your reason for switching to waterborne paint, you need to know what steps are necessary for this transition. This includes training, equipment and disposal. Let’s start with training.

All of the major paint manufacturers offer training classes and it is highly recommended that you and your staff attend such sessions. Experience has shown that the shops that achieve the best results with the use of waterborne paints, and have the easiest transition to this new technology, are those that are properly trained. The topics that are usually covered include mixing ratios, handling and storage, shelf life, spray techniques and disposal. In addition, it is very important that the instructions provided by the paint manufacturer be strictly followed. Greater success has been found by those who follow the instructions to the letter as opposed to those that experiment with the recommended steps.

With regards to equipment, you can still use your High-Volume Low Pressure (HVLP) spray guns, but you should have dedicated pieces. In other words, those guns that are used with waterborne paints should only be used with waterborne paints. These guns should have plastic and stainless parts to prevent the formation of rust. Finally, specially-designed air caps and the use of the correct fluid tips will give the best results.

Cleaning your spray guns is more of an issue with waterborne paints than the guns that are used to spray solvent-based paints. First of all, waterborne paints are not very tolerant of dirt and oil; therefore, keep these guns especially clean. After you’ve completed a paint job, clean the gun right away. While the guns are not difficult to clean, if you wait too long to clean the guns, the dry paint inside can be very difficult to remove. It sticks to metal parts better than solvent-based paints and is no longer water soluble after it has dried. And guess what? This paint is impervious to traditional cleaning solvents because it is water-based.

Another piece of equipment in your shop that might require some modification is the paint booth. Basically, what you need to do is move more air to allow the waterborne paint to dry. Heat alone is not enough; increased circulation is needed. Let’s look at an example of this principal. You wash your favorite sweatshirt and hang it on a clothesline outside to dry. If the temperature is 80 degrees, it will dry. But it will dry even faster if it is a breezy day. Some shops are doubling the air flow in their booths.

Finally, maintenance of your compressed air system is more critical than it was when you were spraying solvent-based paints. Excess moisture in the air lines will affect the drying times, finish quality and wwdurability because you have added water to a water-based product. Some shops are using a desiccant dryer, refrigerated air dryer and/or moisture traps to maximize the performance of the waterborne paint.

Disposal of Waterborne Paint

Just because this new paint is water-based, that doesn’t mean that you can pour the waste down the drain. That’s a no-no. Waterborne paint still contains some hazardous material and its disposal should be treated as such. The best solution is to have separate storage equipment; don’t mix it with other waste solvents.

It’s important to note that the EPA won’t require another permit for waterborne paint products. That’s a relief. But the guy who hauls away this stuff might charge you an additional fee. Many of the solvent-based paint products are burned as a fuel, but the water-based byproducts do not have the same BTU content. In other words, its value is less than solvent-based waste. But as long as you use a fully licensed waste hauler, you shouldn’t have any disposal issues.

Waterborne paint is the way of the future. If you haven’t already, take time to consider switching over.