Maintaining your spray equipment in proper working order isn’t just about keeping it out of the shop to save on repair costs. Doing so also improves your productivity in painting tasks, and prevents having to take your sprayer apart in the field. And most importantly, smooth-running equipment results in the best-quality finish for your customers.
Within your paint-spraying arsenal, you may have a wide range of equipment, from HVLP and conventional to airless or even static charge. But for Peter Weiss, president of the industrial painting company Induspray, success ultimately comes down to cleanliness. “It may sound obvious, but keeping your equipment clean is going to reduce your failures and troubleshooting down to a quarter or less,” he says.
Gas-powered, electric-powered, and air-powered paint sprayers all basically clean up the same way. Use whatever the coating manufacturer recommendation for cleaning, whether soapy water (preferably hot) for water-based paints or a compatible thinner such as mineral spirits, lacquer thinner, or xylene for petroleum-based paints. If a novice in your crew accidentally cleans with the wrong cleaner, the results can be catastrophic—creating a cottage cheese-like sludge in the machine.
Chris Noto, director of products for WAGNER, recommends starting in bypass mode; using the appropriate solution running through the suction tube and returning through the bypass hose for three or four minutes. Once that’s clean, switch the unit from bypass mode (or priming mode) to the spray mode to clean the hose and the spray gun itself.
“One of the biggest mistakes is leaving the tip on the gun while you’re cleaning,” he says. “You want the sprayer, basically, to free-flow during the process, moving a significant amount of cleaner through the pump and hose till it runs clear. Leaving the tip on also drastically reduces the life of the tip. You can add 20% or 30% to its life by cleaning without it.” Cleaning a handheld sprayer that’s been used for water-based paint is even simpler: just dump the unused paint back into the bucket, rinse the cup thoroughly in a slop sink, and spray through one or two full paint cups of hot, soapy water.
Spending an extra five or 10 minutes to remove all the dirty solution is worth the effort, ensuring that the next time you pull the trigger, the equipment is perfectly clean—and that you won’t have to unclog a hose or take apart the sprayer tip to remove debris. In addition, thorough cleaning will eliminate problems on color changes and product changes, such as from a dark color to a light color.
Cleanup after using a two-part epoxy, urethane or polyurea requires additional diligence. “You really need to pay attention to the pot life, and if you don’t flush that pump, you’re going to be in trouble,” says Bob Zaffino, president of The Paint Project, which provides sales, service, and design of spray equipment and systems. “With two-component coatings, they tend to fuse to the metals, nicks and cavities inside the sprayer.”
BEYOND CLEANING: BEST PRACTICES
In addition to appropriate cleaning, there’s a wide range of tricks of the trade that even the most novice members of your paint crew need to be aware of in order to keep spray equipment running smoothly:
Pay attention to the pump. The first sign of a problem with a piston pump is when the upper packing begins to leak. That’s a visual notification … paint will come out of the fluid section, which can be observed through a weep hole opening, and it’s time to have the pump serviced. For gas-powered units, you’ll want to heed the manufacturer’s recommendations on when to change the oil—generally 200 or 300 hours of run time.
Tips on spray tips. Worn-out spray tips can cause problems with usability as well as finish quality. “The obvious sign that your needles or seals are worn is that they will start leaking or dripping,” says Weiss. “Water-based paints are generally, although not always, more abrasive. It’s just the nature of the ingredients that go into paint, and that’s what wears out the guns, tips and seals. When you’re dealing with airless sprayers, the tips will only last about 50 gallons.”
Don’t neglect your filters. Dirty filters can cause problems with paint flow or, in a worst-case scenario, the need to repack the pump more often. The good news is that maintenance is as simple as taking out the filters, rinsing them, and reinstalling them. “Everyone recommends it, but it’s a step a lot of people skip,” says Noto. Most professional sprayers have three filters in them, designed to prevent mechanical issues and ensure you’re spraying clean paint: 1) an inlet screen (aka, rock catcher) on the tube that goes into the paint itself and catches debris such as grass, leaves or dried paint; 2) a filter on the sprayer itself; and 3) a filter in the handle of the gun. “They are cleanable and reusable to a point, but will eventually need to be replaced, depending on the coatings you’re using,” says Noto. “If you’re doing deck stain, they could last a year, because it’s extremely fine-ground and thin. If you’re using an inexpensive barn paint or line-striping paint, you’ll have to replace them more often. It’s not so much the hours of use, it’s what you’re spraying.”
Watch the workspace. In addition to paying attention to internal cleanliness of the unit, you need to make sure your paint sprayer is operated and stored in a clean environment. “If you’re running a sprayer in a really dirty or dusty facility, it’s going to be hard on the equipment,” Weiss says. “Operating an electric unit in a dusty environment, for example, you’re going to burn out the armature and brushes, and the engine will start tripping breakers. And it may sound like common sense, but you also should never set up pumps below where you’re painting. Overspray dust is gritty, abrasive, and very hard on any equipment with moving parts.”
Rust never sleeps. Water-based paints may be kinder on the environment, but water itself can cause problems in the inner workings of your sprayer due to the minerals and iron in the water supply. “Many of the parts are carbon steel or chrome-plated rather than stainless steel, so there’s a lot of rusting that occurs, especially on the pickup side and the pump sections itself,” says Zaffino. After you’ve flushed the sprayer with hot, soapy water, he recommends storing it with RV antifreeze or another rust and corrosion preventive if you’re not using the sprayer for a week or more. With solvent-based paints, mineral spirits or compatible solvents should be used for flushing the sprayer. For longer storage, using a 50/50 blend of mineral spirits and non-detergent oil won’t dry out, because they’re petroleum-based.
Heed the temperature. Paint that is too viscous is not only hard to atomize, it will produce subpar results. “During cold weather, when you throw the paint in the back of a pick-up, drive an hour to the job site, and the temperature of the coating drops significantly, you’ll have to increase the pressure to avoid tailing in the spray pattern,” Zaffino says. “You need to bring your paint to room temperature for it to flow properly.”
Pre-filter your paint. The multiple-filter system will catch most of the crud before it gets into the spray system and causes clogs. It can be prudent, however, to filter the paint before it even goes into the sprayer or before you start to siphon from a can or bucket. A simple strainer, or even a pair of pantyhose, can eliminate problems with a plugged-up siphon and resulting pump malfunction.
Prepare for winter. Colder weather will be arriving shortly—which means winterizing your equipment. “In warm climates, you can leave water in the sprayer as long as you use a rust and corrosion preventive,” says Noto. “But in cold weather like we have in Minnesota, it can freeze and cause damage, which is why most contractors pump their sprayer dry. Some people use gasoline or antifreeze, but we tend to stay away from that because it can be poisonous. Mineral spirits are a great winterizer. It pushes all the water out and leaves a coating on the interior surfaces so it makes it through the winter. When you go back to a water-based coating, you just need to run water through it to pump the mineral spirits out.”
Zaffino’s company got started in—and continues to do—a significant amount of repair business, giving him a mechanic’s-eyes view of what sends spray equipment into the shop. “I know no one likes to read manuals, and I don’t like to either,” he says. “The fact is, about half the pieces of equipment we see in our shop are in here because of negligence. I can’t stress enough how important it is to be trained on things like safety, use, operating techniques and maintenance.”
From small residential contractors to very large industrial contractors, Weiss believes there is one thing in common: the need for productivity. “Being competitive on a spray job means we need to be efficient about labor and material, particularly paint,” says Weiss. “With a sprayer, the way you achieve that is using the correct gun on the right piece of equipment, having a clean pump with no worn parts, and adjusting the pressure to the correct level to atomize the paint particles. If you do that, it gives you more control and makes the equipment easy to use; and if you don’t, it’s going to be difficult to do high-quality work. Experienced contractors recognize this and make sure the equipment that goes onto a job site is in good repair.”