How Long Can You Leave Paint In A Sprayer? (Airless & HVLP)

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Paint sprayers save us time and effort on our home DIY projects. You can paint your walls in a matter of minutes, but afterward, how long will the paint last?

Are you taking some time before your next coat, or just curious about the lifespan of thin and thick paint?  

If you're wondering how long you can leave paint in a paint sprayer, this guide will give you the answers you need, along with tips to preserve it for longer.  

Can I Leave Paint Inside A Paint Sprayer? 

Generally, it’s not recommended you leave  leave latex paint or same paint in your airless paint sprayer overnight.

This is because latex paint and acrylic paint can dry quickly in the container and lead to issues with the function such as the ones below.

Checking Paint Sprayer
  • Filter Blockage 
    The filter provides a necessary cleanup of impurities from the paint. Once it’s dried and caked onto the filter, it makes it much harder to do so. This can lead to poor performance of your sprayer or rougher finishes.  
  • Clogged Spray 
    Once the paint has dried up in the nozzle or any of the tubes of spray gun, it’s going to struggle to spray new paint. An excessive buildup of old paint in the nozzle will eventually lead to a complete block, and no paint will be able to spray.  
  • Blocked Intake 
    The suction nozzle of spray gun brings the paint up from the container into the spray gun. If this becomes jammed with old, flaky paint, then you can expect a lot slower use or splatter from the nozzle. 

    The harder it is for the extraction, the more likely the sprayer will malfunction. 

    The time between cleaning will also vary between different paints; oils will take longer to dry and can be left longer, but a waterborne paint will need to be cleaned within 20 minutes of use. 

    Thankfully, there are things we can do to store paint in airless paint sprayers and stop them from drying quickly. We will explore different methods below.  

How Long Can You Leave Paint In A Sprayer Without Problems?

Most manufacturers agree that you could leave paint in the sprayer for approximately 2 - 4 hours before you begin to run into problems. Theoretically, that should be enough time to leave a coat on before spraying again. 

Airless sprayers can use paint pots for applications, and storing the same paint is much easier; simply put the lid back on. Unlike airless sprayers, HVLP models, you’ll have shorter lengths of time to store.  

Different companies will also provide different information. For example, both Wagner [1] and Graco sprayer [2] do not recommend leaving paint in a sprayer overnight.

Can you leave thick paint in the sprayer overnight?

Leaving paint in the sprayer overnight should, as a general rule, be okay. However, paint sprayer sit within paint or paint sit in the sprayer overnight should only be done if necessary, for example, if you're going to continue using that same sprayer in the morning for the next paint coatings then you can leaven paint sit in the sprayer overnight. 

But for some helpful tips, we’ve compiled a table below on how to keep paint from drying. 

Wagner HVLP Sprayer

Wagner Airless Sprayer

Disassemble the sprayer, take off the nozzle, suction cup, and clean interior tubes. Cover the paint pot as airtight as possible, which should preserve it for a night.  

Remove intake from paint and place into a bucket of water. Scrub the outside of any residue paint. Place the spray gun in water along with the tip & tip housing. You can leave it in the water for a few days if need be. 

Graco HVLP Sprayer

Graco Airless Sprayer

Remove paint canister from the spray gun and seal as airtight as possible. Remove the nozzle and intake valve, and run under the faucet at high pressure to clear paint. You should resume painting within a day after storing the HVLP model. 

Replace the lid of the paint. Relieve any remaining pressure from the sprayer. Squirt a little Graco Throat Seal liquid into the pump of the sprayer. Clean the outside of the siphon hose and leave inside a bucket of water along with the spray gun, tip, and tip housing. You can leave for up to 3 days.  

graco paint sprayer

Potential Problems When You Leave Paint In A Sprayer 

The real main issue that’ll arise is paint drying. In turn, this leads to other problems in your paint sprayers, for both airless and HVLP. So, what are the issues it causes? 

Blocked Filter 

As mentioned before, the filter will clear out impurities from the paint, and give you a nice, even finish. When dry paint is jammed inside, it’s not going to work.

This leaves any dust, particles, or debris in the paint to be sprayed out onto your walls, fences, etc. Dried paint can take hours to clean from the filter.  

Clogged Sprayer 

It’s simple; if the insides of the HVLP and airless sprayer are clogged with old, dry paint, then new paint won’t be able to get through. 

The inner tubes for paint and air to merge won’t be as effective because there’s no room for them to work together. You’ll experience splatter, dribbling paint, or no paint at all.  

Damaged Components 

Suddenly, clogged sprayers will be the least of your problems. Leaving paint on the nozzle to dry will make it doubly hard to remove. The excess scrubbing and cleaning could lead to your nozzle breaking.

The old paint inside of the nozzle, if not cleaned out, won’t allow new paint through and cover the nozzle completely.  

Chipped Finish 

The old paint left inside will separate while drying, meaning the oils or impurities left inside will remain on the surface.

When this mixes with the new paint, it won't get filtered out and will spray directly onto your surface. This will make paint chips or peeling paint much more likely and will give you a costly job to fix later on.  

How To Get The Remaining Paint Out Of A Paint Sprayer? 

If you want to avoid any drama later on, it's best to ensure there's no paint left in your sprayer. Below is a guide on how to remove the remaining paint out of a sprayer: 

Airless Sprayer

  1. 1
    Dip the intake hose of the airless sprayer into a bucket of water, and spray the last bits of paint back into the pot.
  2. 2
    Stop just as the water comes out of airless sprayer, then spray again into a sink or bucket until the water is clear.
  3. 3
    Dismantle the paint spray gun (nozzle, tip house, any connections) and clean the parts in warm, soapy water.  
  4. 4
    Use a trimmed brush to scrub off any remaining paint from the outside of the airless sprayer. You can use a paint thinner or mineral spirits if this is too difficult.  
  5. 5
    Set aside to dry airless paint sprayer on a clean towel or dry area of your garage. 
wagner airless paint sprayer

HVLP

  1. 1
    Disassemble the spray unit: remove air vacuum, paint container, and nozzles.  
  2. 2
    Pour the remaining paint back into the pot. Remove the suction nozzle from the container lid and soak (along with the nozzles and top caps) in warm, soapy water. 
  3. 3
    Use warm soapy water to clean out the paint container, making sure you clear all paint from the inside.  
  4. 4
    Use a small brush to scrub the tubes, nozzle, and suction cup. Make sure there is no paint in any of the connections.  
  5. 5
    Set aside to air dry.  

You may need to clean your HVLP sprayer multiple times to remove any dry paint. But once done, it’ll save you time and effort later. 

Leaving Paint In A Sprayer FAQs

Can I leave paint in my sprayer between coats? 

You can leave paint in a sprayer for up to 4 hours between coats, but it's recommended to spray onto a tester sheet periodically to prevent clogging.

Can you leave paint thinner in a sprayer? 

Generally, it is not recommended to leave paint thinner in a sprayer, because the leftover thinner can cause problems once you come to use it again in the future.  

How long does it take before paint dries in a paint sprayer? 

Anything over 4 hours is a safe assumption before the paint dries. If it's waterborne paint, it can take as little as 30 minutes to dry. Thicker oil-based paints won't dry as fast.

How can I unclog a blocked nozzle? 

To unclog a blocked nozzle, disassemble the nozzle and leave to soak in a water solvent for a few minutes. Blow air through the nozzle while it is wet, and use the fine brush or needle to remove any residue from the nozzle.  

Conclusion

Leaving paint in our spray guns is going to cause us endless problems. To avoid any issues while using your sprayer, always clean thoroughly after use.

Even if you don’t have time to clean immediately after, try to soak them in water to come back to later. To keep your trusty spray gun working for longer, let it soak its paint away! 

References:

1. https://www.wagner-group.com/uk/

2. https://www.graco.com/us/en.html