Why Paint Sprayer Won’t Build Pressure – Explained!


Last updated: June 7, 2023

Discover the causes and solutions of paint sprayer that won’t build pressure.

Why Paint Sprayer won t Build Pressure

Sprayers need to operate with the correct pressure setting to ensure proper atomization of the material and to deliver a flawless finish. When there’s little or no pressure build, you will end up with no spray or insufficient coverage.

If you’re in a pickle with your device and it’s not building pressure, we may have the perfect solution for you. In this article, we will look at what causes a pressure drop in sprayers and how you can fix it.

Why paint sprayer won’t build pressure

A drop in your sprayer pressure can be caused by several things – a clogged nozzle, a clogged filter, a low-pressure setting, a broken clutch, a damaged valve, and using a hose that is too long. You will need to troubleshoot the machine to identify and fix the particular problem. 

Why Is Paint Sprayer Pressure Important? 

The right operating pressure is vital to properly applying paint to any surface. It is how the paint material is atomized in an airless sprayer and effectively “pumped” over a distance. It is also responsible for the rapid speed and flawless finish a sprayer provides compared to a roller or paintbrush. Check out the reasons you should use a roller or spray paint for your paint job through the link for more insights.

When pressure is too low or insufficient, the material will not be sufficiently atomized, which often leads to an uneven spray pattern. Likewise, if pressure is too much, the paint will be sputtered too much, which results in excessive overspray and increases wear of the spray tip, seals, and other components.

So, besides choosing a device that will deliver enough pressure for your project, you want to use the right operating pressure. Most sprayers (irrespective of the type) usually come with a pressure regulator that lets you adjust the pressure to your coating and the size of the project.

What PSI is Needed For Spray Painting?

This depends on the sprayer you’re using, the size of your project, and your personal preference. No two sprayers usually have the same pressure settings.

If you’re using a spray gun that uses compressed air, then it’s likely HVLP or LVLP. HVLP stands for high volume, low pressure, while LVLP is short for low volume, low pressure.

In both cases, the machine operates with a low pressure to finish the job. Experts generally recommend 10-15 PSI for spray painting, but this can be increased to 28-29 PSI to ensure smoother coating.

Specifically, if you’re using an HVLP gun, you will often need at least 25 PSI to power the machine. A good example is when you need to spray a car. The pressure can rise to 35-40 PSI if you’re painting a large surface or something that requires higher atomization.

For an airless paint sprayer, you will need to check the product data-sheet to know what pressure to use for the machine. In addition, you need to consider the size (height) of the hose you’ll be using, as a longer hose will require more pressure to push the material to the target surface. This is often the case when you’re painting a storey building and need to push paint over several feet.

Ultimately, to get the ideal pressure for any sprayer, you should check the specific recommendations for that model.

What Causes Paint Sprayer to Lose Pressure?

If your sprayer isn’t building pressure, there are a few places to look: the nozzle, the filter, the clutch, and the pressure settings. Let’s look at each one in more detail:

1.Clogged Nozzle

The nozzle is one of the first places to look when you have a sprayer that doesn’t build pressure. Pressure loss often occurs when there are clogs or blockages in the nozzle tip. It could be sand, dirt, or other solid matter that has entered the tip or pump system. Paint buildup from residues can also clog the nozzle. When this happens, the tip will not be able to atomize well, and you need to take quick action to unclog the can.

2. Ramp Up The Pressure

Sometimes you may be using the wrong pressure settings to operate the sprayer. When the pressure is too low, the machine will be ineffective and will not pump material as it should. This can happen with both beginners and experienced DIYers.

3. Clogged Filter

Another thing that could cause your sprayer to output low pressure is when the filter is clogged or jammed with paint or solid debris. Most sprayers have a filter system that removes any solid impurities in the paint mixture. This ensures other components, such as the pump, suction, hose, nozzle, and wand, don’t get clogged.

Besides cleaning filters, you will need to replace them from time to time as they get worn out. Some larger sprayers may have multiple filters. If one filter has issues, it can cause the entire unit not to function properly.

4. Broken Clutch

A broken or displaced clutch can also cause a pressure drop. The job of the clutch is to drive or control the pump while the pump moves the fluid through the system. This arrangement reduces the work on the engine and ensures it doesn’t overuse the pump.

Consequently, when you have a faulty clutch or one that is displaced, the gun will not work properly, or the pressure output will be lower than it used to be.

5. Dirty or Damaged Valve

If your sprayer is working but doesn’t build enough pressure to pump the material, the problem could be coming from the valve. It could either be dirty or damaged.

The inlet valve ensures the material flows correctly. But it has to be closed completely to create the pressure that is needed; otherwise, some of the paint will escape through the back hose, causing the machine to pump in a different direction.

Inside the valve, you will find other components like the balls and seats. The ball needs to move in order to create a blockage which is required to build pressure. If the ball gets dirty or damaged, it may stick and not move, causing the material not to come out properly.

Troubleshooting & Fixing A Paint Sprayer That Won’t Build Pressure 

Follow the steps below sequentially to troubleshoot and fix your sprayer’s pressure problem. You don’t have to do everything on the list. Just start with the simpler steps; once the issue is resolved, there’s no need to continue. 

  • Inspect the nozzle: Remove it from the trigger and check if it is clogged. If it is, clean it and take out any solids that may be blocking the lines. If the clogging is too much and cannot be cleaned or you notice a bigger hole in it, then the nozzle is seriously damaged or worn out and need to be replaced.
  • Change the spray tip: Sometimes, the problem may be that the nozzle you’re using is too big. In this case, you want to change the tip size. Make sure the spray tip is compatible with the paint. If it’s too large, it will not be able to pump enough material. In other words, use a thicker tip for thicker paint!
  • Increase the pressure: Check the pressure settings and make sure it’s not too low. If it is, ramp it up; that might fix the problem. Even if you set the pressure correctly the first time, sometimes paint with the same viscosity may have different pressure requirements depending on the brand. So, always check and make sure you’re using the correct pressure. 
  • Clean the filters: Check the filter in the tank or backpack (depending on the model) to see if it’s clogged. If it is, clean it out. As earlier indicated, some units may have multiple filters in different locations, such as the pump, gun, inlet screen, etc. For such systems, clean the filters individually. Flush out the backpack with water and rinse the tank a few times. See if this fixes the problem. If it doesn’t, or you’re not able to clean out the debris or paint in the filter, consider getting a new filter.
  • Put the clutch in place: Check the clutch to ensure it’s in alignment with the rest of the unit. To do this, you will need to disassemble the sprayer. If you notice any problem with the clutch, follow the instructions provided by the manufacturer to fix it. The exact steps will be different for each model. 
  • Clean or replace the valves: To fix a problematic valve, you need to dismantle it first. Then clean or replace it depending on what you find inside. To remove the valve, you either hit it gently with a hammer or unscrew the bottom to reach the base. Once you disassemble the valve, get the balls and seats out and clean them thoroughly. Replace any broken or damaged parts. 
  • Other suggestions: Make sure the paint you are using is not too viscous, especially if you’re using an air sprayer. If it is, thin it down; otherwise, opt for a larger spray tip. It’s also recommended to strain the paint to get rid of dirt and debris. In addition, make sure your hose is not too long. 

How to Select the Correct Pressure for Your Paint Sprayer 

Selecting the correct pressure for your sprayer is important for achieving a good quality finish. Proper pressure settings will prevent runs and lines in the spray pattern and ensure a smooth finish.

Luckily, the process for setting optimal pressure is relatively simple if you know what to do. Follow the step-by-step guide below to select the correct pressure settings for your sprayer.

  1. First, set up the machine following the instructions in the user manual. Make sure you have your safety gear on. 

  2. Next, lay down some scraps of cardboard. We recommend using a darker color if you’re using lighter-colored paint. This will make it easier to see the spray pattern.

  3. Now, set the sprayer pressure to the lowest setting and trigger the gun quickly. Spray a small amount on the cardboard. Notice how the paint is expelled from the gun. If you notice it’s spitting as it leaves or the fan pattern is not consistent, it means the pressure is not high enough. You will want to ramp it up a bit. In this case, proceed to step 4. However, if you notice the fan pattern is uniform, and there’s adequate atomization, it means you’ve gotten the correct pressure. In this case, move on to step 5. 

  4. Next, dial up the pressure and test again. Repeat the process until the paint is sufficiently atomized. 

  5. Now that you’ve found something that works, take note of the pressure setting in case you need to refer to it later. 

Why is My Paint Sprayer Sputtering?

If you’re using your sprayer regularly, it is likely to splatter or sputter at some point. The guide below shows how to identify possible causes and fixes.

1. Loosed Nozzle

One of the most common causes of sputtering in a sprayer is when the nozzle is not tight enough. So, start by checking the nozzle for any looseness and ensure it’s properly screwed into place. Make sure the threads are not stripped.

When the nozzle is loose, air enters and interferes with the fluid supply, which results in sputtering or spitting. To fix this, tighten the fluid nozzle. If the nozzle cannot be tightened due to possible damage, we recommend getting a new one.

2. Clogged Nozzle

If the fluid nozzle is clogged, it will negatively impact the spray pattern, which is undesirable. Upon inspection, if you notice the nozzle is clogged, clean it thoroughly together with the fluid passage.

Ensure there are no particle buildups or hardened paint in the spray gun. Use an appropriate cleaner. In addition, replace any damaged seals or O-rings.

3. High-Pressure

Sputtering is common with airless sprayers because of their high-pressure requirement. Depending on the type of sprayer you’re using, you will find it easier to avoid sputtering if you keep the pressure low. This way, the paint will come out with less force. Start at the lowest pressure, then increase until you’re satisfied with the spray pattern. Using lower pressure also increases the lifespan of the spray tip.

4. Worn Spray Tip

All spray tips eventually wear out. However, using abrasive materials and higher pressure will wear out the tip sooner. Worn spray tips usually give a hissing sound. Another sign is a change in the spray pattern. For instance, a circle resulting from an oval spray pattern. When you notice this, the tip is probably worn out and needs to be replaced.

Why Paint Sprayer Won't Build Pressure

Why Does My Paint Sprayer Have no Suction?

If your paint sprayer has no suction, there are a few things that could be responsible.

1. Too Much Material

First, the machine might be overloaded with paint, which may cause the clogging of the nozzle or one or more of the different filters.

If the suction filter is clogged, you will need to remove it and clean the screen with a brush. Be sure there is no dry paint in it because that can be sucked into the pump and obstruct the spray tip.

Sometimes, it might be the gun filter that is clogged and needs cleaning. This often happens when the pump draws paint but can’t release it through the nozzle. Before checking the gun filter, make sure the machine is powered off and release the pressure inside the spray valve by setting it to prime position. Then, you can dismantle the handle of the gun to access the filter inside.

Clean the filter thoroughly if it’s dirty, rusted, or filled with dry paint.

2. Paint Jam

Another reason why your sprayer may not have suction is when the nozzle has a paint jam. Here, the motor runs but doesn’t pump material. The problem can be connected to nozzles and filters.

Check to ensure these are clean because if they are dirty, they will prevent the material from flowing. Remove and clean them thoroughly and replace any damaged parts.

In addition, ensure you clean the sprayer every time you finish a project. Also, lubricate the pump (put some oil inside) if you’re storing the machine away for a period of one month.

Techniques for Using a Paint Sprayer

  • As with any other equipment, using a sprayer requires some practice. If you’re a beginner, you may want to start out spraying water until you become comfortable with spray techniques.
  • Be careful when handling the spray gun. The tip can deeply inject the skin, leading to a serious injury or even death.
  • Always lock the trigger when you’re using the spray gun. Also, remember to shut off the machine before doing any maintenance or repairs.
  • Maintain consistent distance. Hold the gun about 12 inches away from the target surface. And try to maintain the gun position and work within your reach.
  • Avoid fanning the spray gun, as that result in an uneven finish. Do not fret, if you experience uneven finish, we have a whole post on how to solve uneven finish.
  • Keep the gun moving before pulling the trigger, and continue your stroke after releasing the trigger. This will help prevent excessive material at the start and toward the end of each stroke.
  • Don’t use paint without straining it first. This is because even new products can contain flecks of dried paint which can clog the machine and damage the pump over time.
  • Clean the machine after every use to prevent clogging. You can use water or any suitable solvent. Run it through the system until it’s clean.
  • When storing the system away for long periods, store with mineral spirits inside to prevent rusting.
  • To prevent the nozzle from clogging, clean the tips every time you finish using the sprayer. This will not only prevent pressure loss but also ensure the device lasts longer.

FAQs – Paint Sprayer Won’t Build Pressure

What Causes Airless Sprayer Not To Prime?

If you have a sprayer that won’t prime, there are a few things that can be responsible. 

  • The valve is set incorrectly
  • There’s dirt or dried paint on the screen
  • The suction tube is not fully dipped into the material
  • There’s leakage in the suction tube
  • The valve is worn out

How Much PSI Do I Deed To Run a Spray Gun?

This depends on your project’s size and the spray gun you’re using. No two sprayers have the same settings. For most spray patterns with lower pressure requirements, you will often need around 15 to 50 PSI. Typical pressure settings are 15-20 PSI.

How Many PSI Do You Need To Paint a Car?

To ensure consistent flow, opt for at least 15 PSI when you need to paint a car. But sometimes, this might not work well with some car paints. So, you may want to go for a higher HP compressor – anything between 20 to 29 PSI is recommended for better results.

Can I Use a Small Air Compressor For Spray Gun?

Yes, you can, but it won’t yield the best results. A small air compressor may work fine if you’re using the sprayer for a brief period (i.e., a few seconds at a time). But when you need to use the gun for longer periods (which is often the case), a larger compressor would suffice. Spray guns, generally, require higher volumes of air because they have to provide continuous flow to achieve a similar texture across the workpiece.

Can a Pancake Compressor Run a Paint Sprayer?

Yes, it can as long as it meets the requirements of the sprayer, especially with regard to pressure (PSI) and flow rate (CFM). In most cases, the compressor will not work well with the spray gun. Besides pancake compressors, you can also try using pontoon or hot dog compressors to run a paint sprayer, but these are not the standard options.

Content Summary – Paint Sprayer Won’t Build Pressure

Like every piece of machinery, paint sprayers comprise of different bits and pieces that work together to produce the desired results. A single chink in the armor can cause the whole unit to shut down or not work properly. When it comes to pressure issues, there is no fast rule. You will need to troubleshoot the system to discover exactly where the problem is coming from. Once you do, it’s easier to fix the problem, especially if you follow our recommendations above.

Ultimately, to get the best results, you want to choose a pressure that is suitable for your project size. There’s no set rule to doing this; you will need to evaluate the overall picture. Ideally, you want a pressure setting that will eliminate any tails in your spray pattern and reduce overspray and wastage.

We hope you found the guide helpful. Let us know if you have any more questions about why your paint sprayer won’t build pressure.

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