What to Do When the Spray Gun Fails to Spray Paint?
4 Answers
Solutions for a spray gun failing to spray paint: 1. If the spray gun is not spraying paint, it may be due to a clogged paint tube. Clean the paint tube thoroughly; 2. If the paint tube is not clogged, check the paint supply pump to see if the suction cup is blocked. If it is, clean it properly; 3. Check whether the pump is functioning correctly to draw and pump paint. If there is an issue with the pump, improper paint suction can also cause the spray gun to fail to spray paint. Cleaning the pump and suction cup should resolve the issue. Precautions before using a paint spray gun: 1. Clean the nozzle. New paint spray guns often contain a lot of anti-corrosion oil, which must be cleaned before use. Otherwise, it can severely affect performance or even render the gun unusable. Also, remove grease and metal shavings from the nozzle threads and other threaded parts; 2. Clean the interior of the paint spray gun. Cleaning the interior requires the use of a paint cup.
I've been doing automotive painting for almost ten years, and I've seen too many cases of clogged spray guns. First, check if the paint is mixed too thick—if it's like honey, it definitely won't spray properly. Add some thinner and stir it well. Then, check if the air pressure is sufficient; the compressor gauge should read at least 40 psi or higher. If the issue is with the spray gun itself, the most common problem is the nozzle being clogged with dried paint residue. You’ll need to disassemble it, soak it in a dedicated cleaner for half an hour, and use a needle to clear every tiny hole. Last time, my apprentice forgot to clean it, and the entire spray gun was ruined the next day. A worn-out seal can also cause air leaks, but replacing it only takes a few minutes. Remember, you must clean the gun immediately after painting—it’s just like washing dishes after a meal.
Last year when I was spraying my motorcycle at home, I encountered the same situation and spent half a day figuring out the problem. First, check if the paint can is empty—don't laugh, some people really forget to add paint. Then, see if the spray gun trigger is stuck; sometimes a rusty spring can cause this. A normal reading on the pressure gauge doesn’t always mean there’s enough pressure—I once had a hose flattened by a wheel, cutting off the airflow. If the nozzle is clogged, soak it in some banana oil and gently scrub it clean with a toothbrush. Also, remember that different paints require different thinners; using the wrong one can cause clumping. After using the spray gun, hang it upside down to prevent residue from accumulating in the barrel.
Our repair shop encounters car owners with spray gun failures every week. Paint issues account for 70% of the cases, either due to insufficient mixing or incorrect dilution ratios. Air-related problems make up the remaining 30%, which could be caused by clogged air compressor filters or air hose leaks. The most vulnerable part inside the spray gun is the needle seal—once worn, it must be replaced. A simple troubleshooting method: first remove the nozzle and soak it in solvent, then increase air pressure and test-spray. If that doesn't work, disassemble the gun to inspect components. For daily maintenance, always flush the gun three times with dedicated cleaner immediately after use—don't skimp on this cost, as buying a new spray gun would cost half a year's supply of cleaner.
