Troubleshooting Common Spray Issues: Runs, Orange Peel, and Fisheyes

Troubleshooting is a form of problem-solving, often applied to repair failed products or processes on a machine or system. Obviously, the ideal situation is that every commercial coating or spray paint application will go on flawlessly and without issue. The unfortunate reality of our field is that even the best and most knowledgeable sprayer can come across unplanned issues.  So, you're out on a job, and problems arise - now what? Join us as we break down the most common spray issues, what causes them, and what you can do to prevent them before they happen.

PAINT RUNS, ORANGE PEEL AND FISHEYES - What are they and can they be fixed?

• Paint Runs - "Why is my paint running/sagging?" is the most commonly asked question post-commercial spray paint application regarding finish defects. A paint run (or sagging) occurs when excess paint pools on a vertical surface and gravity pulls downward, creating a drip. It is caused by applying too much paint, holding the gun too close, moving too slowly during the application, or using paint that is too heavily thinned. To avoid runs, adjust your equipment and spray technique. You can do this by adjusting the fluid output, optimizing your air pressure, controlling your spray distance, adjusting speed if needed, and checking your viscosity. You can adjust your fluid output by turning the fluid control knob clockwise to reduce the amount of paint flowing through the gun at any given time. You can optimize your air pressure by increasing it slightly to improve atomization or even by switching the nozzle tip to a smaller orifice to reduce fluid volume. Keep your gun at a consistent distance of 10 to 12 in from the surface and adjust the speed to a quicker and more continuous spray. When you have stopping points or inconsistent distances from the surface, it can inadvertently cause too much paint to collect in one specific area. Ensure your paint is not over-thinned! If you notice running while the paint is still WET, you can dab it smooth with a clean cloth and immediately smooth it out. In the event your Paint has dried before you notice the run, you will need to sand the areas affected down and repaint, or in some cases, you should be able to buff it out and re-coat.
• Orange Peel - Orange Peel is a bumpy, textured paint defect that resembles the skin of an orange. It occurs when paint droplets fail to break apart finely enough due to poor atomization in the paint or when the paint dries too fast, preventing the droplets from leveling out into a smooth, glossy film before solidifying. Orange Peel is caused by improper atomization due to low air pressure, incorrect nozzle size, and, most commonly, a clogged tip. It can also be caused by high paint viscosity, incorrect spray technique, and environmental factors such as temperature or humidity levels. To prevent this from happening, there are a few things you can do. Ensure your paint is at the correct viscosity before application. You can do this by adding an appropriate thinner or solvent so the particles are easier to atomize. Adjust the equipment by increasing the air pressure or fluid volume on your spray gun, and ALWAYS use a clean tip. (We will touch base on cleaning paint nozzles in the next section.) What happens when you need to fix the existing Orange Peel? No worries, you can use a wet sanding technique to carefully sand down the high spots of the textured paint. After wet sanding, the surface will look dull - use a dual-action polisher paired with a heavy cutting compound, followed by a lighter finishing polish to restore shine. If the orange peel is severe, sanding it down may strip the clear coat completely. In this case, you will need to sand the entire section flat and apply a new layer of paint.
• Fisheyes - Fisheyes look like small, crater-like holes where wet paint pulls away from the surface. They are caused by contaminants like silicone, oil, wax, or grease. What causes Fisheyes? Surface contamination, moisture, or air contaminants, and paint incompatibility. Surface contaminants can be anything from tiny traces of oils from cleaners, hand lotion, or even aerosol silicone from other products being applied near your worksite. Moisture contaminants typically come from water or compressor oils getting pushed through your air hose or spray gun. Accidentally mixing different paint bases can also be a factor. To prevent this, there are a few easy steps. If the paint is still WET, immediately stop spraying and wipe the area clean using a grease and wax remover or solvent like acetone. If your paint or coating has already cured, you can sand and feather the surface so that the craters are smooth and the edges do not cause ridges. Take a moment to inspect your equipment - ensure that the air compressor lines feature working moisture and oil filters, as compressor blow-by is a top culprit. Finally, you can always use an additive. Professional painters often use "Fisheye Eliminator" as a mix-in to their paint. It lowers the surface tension, forcing the paint to lie flat over minor contaminants you may have missed in the prep stage.

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EQUIPMENT MAINTENANCE
Typical commercial spray paint gun maintenance involves a strict daily flushing of the fluid passages, weekly deep cleaning of the air caps and needles with compatible solvents, and regular inspection of wearable parts like seals and gaskets. Proper lubrication of moving mechanisms prevents sticking and ensures optimal spray. Here's a quick breakdown of a typical maintenance schedule.

• DAILY MAINTENANCE

1. Flush the System: run the appropriate cleaning fluid through the system until the fluids run clear. Use Water for water-based coatings,  or mineral spirits/solvent for oil-based materials.
2. Clean the Assembly: remove air caps, fluid nozzle, and needle. Soak them in an approved cleaning solvent to help break down any build-up. 
3. Wipe Down: Clean the external body of the gun with a lint-free cloth, dampened with solvent. Never submerge the entire spray gun body as this can degrade the internal packings and seals. 
4. Check your Filters: Remove and rinse out filters and screens after every use to prevent blockages. 

• WEEKLY MAINTENANCE

1. Deep Clean Passages: Remove the needle and nozzle. Use a specialized cleaning brush to clear dried material from the gun's internal fluid passages.
2. Inspect Wear Parts: Check all fluid seals and gaskets for swelling, cracks or damage, which can ultimately lead to leaks and pressure loss. 
3. Lubricate Threads: Apply gun lubricant or manufacturer-recommended oil to moving parts, adjustment knobs, and the front threads where the air cap attaches to keep the assembly smooth. 

• PERIODIC MAINTENANCE: Maintaining the broader commercial spray set-up, such as an airless rig, pressure pot, or HVLP turbine, requires preventive upkeep on a seasonal or hourly use basis. 

1. Spray Tips: Inspect and replace airless spray tips typically after every 40-60 hours of use to maintain fan width and material efficiency.
2. Pump /Pot Seals: Routinely check pump packings and lid seals
3. Piston Lubrication: For airless rigs, check and refill the lubrication reservoir to keep the piston moving smoothly and extend the life of the internal packings. 

TOP QUESTIONS ASKED: TROUBLESHOOTING/COMMERCIAL SPRAY GUN

1. "My Spray Gun is Not Priming? What Now?" - If your commercial spray gun fails to prime, it is usually caused by dried paint, a stuck check ball, or an air leak. Start by relieving system pressure, then check for clogs. Ensure the fluid is being pushed to the intake, and inspect suction seals. 
2. "How Do You Clean Dried Paint from the Spray Tip?" - To quickly clean dried paint from a spray tip, soak the detached tip in a solvent matched to your paint. (ie. lacquer thinner for oil-based paint, hot water or ammonia for latex paint.) This will soften the residue! Then you should scrub with a soft brush and use a toothpick or wire tip cleaner to gently poke debris out of the tip.
3. "How can I correct Fluctuating Spray Pressure in my Commercial Spray Paint Gun?" Correcting fluctuating spray pressure depends on whether you use a compressed air system, such as an HVLP gun, or a high-pressure airless system. For a HVLP/Compressed Air System, set the working pressure correctly, check for pressure drops, and inspect air lines and regulators. Signs that your HVLP/Compressed air system needs help are if your air pressure drops or surges when you pull the trigger. For an Airless Paint Sprayer, you will need to clear clogs, bleed air from your system, check the prime/drain valve, inspect all worn pump components, and ensure that there is an adequate fluid supply. Signs that your Airless System needs help will be if your sprayer is pulsing, surging, or fluctuating during operation. 
4. "What's the Proper Surface Prep for Commercial Spray Applications?"