Heated Nitrogen painting.
So what makes nitrogen so good? It’s better than compressed air because it contains no moisture and the molecules remain a uniform size upon application. Here’s why:
• Nitrogen is anhydrous. That means it has no moisture, which distributes nitrogen-based equipment. The lack of moisture reduces flash times, decreases bake times, and ultimately improves cycle time.
• Nitrogen is inert. That means the molecules don’t expand or contract like compressed air does. The molecules are a uniform size and provide a more solid layer of paint. That means fewer coats of paint have to be applied, which reduces your overall paint consumption.
How It Works
The Heated Nitrogen Spray system takes atmospheric air from your existing air compressor and runs it through a membrane. The membrane traps the nitrogen and removes all moisture out of the air.
The nitrogen is circulated back through the membrane, adding back in some of the other materials that were discharged from the air—like argon, carbon monoxide and other trace gases. That combination of gases produces different sized molecules, which gives a tighter mill build.
• Heating to a controlled temperature. The gas is sent to a delivery hose, which heats the gas and controls precise delivery temperature. That’s important because changes in atmospheric temperature change the viscosity of the paint you’re applying. Painters have to adjust the pressure they spray with depending on changes in the air temperature throughout the day. By heating the nitrogen, the pressure you spray with can stay the same throughout the day no matter what the air temperature is doing.
.• Eliminates puddling. The nitrogen systems provide a perfect mill build—a solid layer of paint. The molecules in the paint are a uniform size and don’t puddle.
• Eliminates haze. “The distinction of image compared to compressed air is night and day. “The paint appears so much crisper.” That’s because solvent in paint creates haze. The nitrogen system eliminates the solvents in paint with heat, and you’re applying fewer coats that contain solvent.
• Improves transfer efficiency. Transfer efficiency is better because the ionized material is pulled into the panel, and doesn’t allow it to bounce back off. You get better coverage of paint on the car. You only have to apply two or three coats of color—rather than four or five—which greatly reduces your paint consumption.
• Reduces overspray. Nitrogen carries more paint directly to the panel, and reduces overspray by about 50 percent. Nitrogen travels twice as fast as compressed air, allowing you to shoot at a lower pressure.
Filters in the spray booth last 40 percent longer because of the reduced overspray. This also leads to less contamination in the paint that has to be sanded and buffed afterward.
• Eliminates flash time. There’s no flash time with nitrogen, no waiting 15 minutes between every coat. “You can go into the booth and spray every coat of paint back-to-back. Painters can even take the clear coat into the booth with him to apply right away allowing him to paint three extra cars every day—and chop two days off his average cycle time.
• Reduces bake time. There isn’t any water in the nitrogen and excess moisture is removed from the paint in the heating process.
“The paint is already starting to kick when it hits the panels. This allows bake cycles to decrease from 30 to 20 minutes.
“We can sand and polish cars just two hours after baking.
• Eliminates reducer. The paint material is less viscous after it’s heated, so it doesn’t take as much reducer to apply.
Return on investment
Shops will watch their material consumption drop due to the improved transfer efficiency, over spray reduction, and the simple fact that you don’t have to apply as many coats of paint. The time frame for your return on investments depends on the number of cars you paint. The more cars you move through, the faster the system will pay you back.
As a rule of thumb, if your shop sprays an average of 10 panels per day, five days per week, you will experience a full return on your investment in a maximum of 18 months with Heated Nitrogen Spray.
Regardless of what type of paint you use—waterborne or solvent—you should save about 30 percent on your materials.