How Long Can You Leave Paint in A Paint Sprayer?


Last updated: June 27, 2023

Discover how long you should leave paint in a paint sprayer and other related information in this guide.

How long can you leave paint in a paint sprayer?

Leaving paint in your sprayer is frowned upon, as evidenced by best practices discouraging it. However, sometimes you may have no other viable option apart from leaving paint in a paint sprayer.

If you are wondering how long can I leave paint in a paint sprayer before it can damage it, then you are in the right place.

In this article, I will discuss the reasons, effects, pros, and cons of leaving spray paint in your paint sprayer. Let’s dive in.

How Long Can You Leave Paint in A Paint Sprayer

For most sprayers (both airless and HLVP), you can leave the paint to sit in them for 1 to 3 days. While you can leave paint sitting in your paint spray gun, the best painting practices dictate that you should clean it immediately after using it if you want to prolong its lifespan.

Can You Leave Paint in the Sprayer Overnight?

Yes, you can leave paint in a sprayer overnight. This is mostly the case when you have to paint an additional coat the next day and still need to finish the paint in your sprayer. 

If you have to leave paint in your sprayer, there are a few things that you need to be aware of:

  • First, you should always leave the sprayer and its intake in a bucket of water to prevent clogging.

  • Second, store the paint sprayer indoors because outdoor temperatures tend to be low, which can lead to the paint thickening. When this happens, it can block your sprayer and damage its mechanism.

  • Finally, remember to leave the nozzle or cap in a thinning solution to prevent blocking due to the paint thickening or drying up.

How Long Can You Leave Paint in a Wagner Sprayer?

If you are using a Wagner sprayer, it is not recommended to let the paint inside for over 3 days. However, there are some products you can use to elongate the time. Most of these are Greco products but are compatible with Wagner sprayers.

How Long Can You Leave Paint in a Graco Sprayer?

So, you know how I keep saying you should not let paint stay in your sprayer for more than 3 days? 

This is still the case with Graco sprayers but with an exception. The exception is that paint can sit in your Graco sprayer for a year or even more if you use the right products.

You must buy Graco Pump Amor, Graco Throat Seal Liquid, and 30wt oil. When used correctly, the products can help preserve the paint and sprayer for over a year.

How Long Can You Leave Paint in a Spray Gun?

For most sprayers, you can leave paint for up to three days. However, if you wish to leave it longer, consider using products like those discussed above. 

Always check if these additives are compatible with your spray gun before buying or using them.

How Long Can You Leave Paint in a Sprayer Between Coats?

Leaving paint in a spray for a few hours or overnight should be okay between coats. You cannot leave it for more than a few days for most sprayers as the paint may thicken and cause clogging and damage to the sprayer’s mechanism.

Is Leaving Thick Paint in a Sprayer Okay?

Yes, you can leaven thick paint in a sprayer. However, since the paint is already thick, it is important to significantly reduce the time you leave it sitting in your sprayer.

Leave it for, at most, overnight if you are using an airless paint sprayer and only for a few hours if you are using an HVLV sprayer.

What you need to know about leaving paint in airless paint sprayers Vs. HVLP paint sprayers

When using an HVLP paint sprayer, leaving the paint for the least time possible is best. Do not leave the paint for any longer than a day.

The main reason is that HVLP sprayer nozzles are particularly fragile and susceptible to damage if the paint becomes thicker.

Also, do not use thicker paint mixtures than outlined by the sprayer manufacturer. If you use a slightly heavier, thicker paint mixture, do not leave the paint sitting for more than a few hours.

Airless sprayers are more robust than their counterparts. You can leave paint sitting in them for up to 3 days without worrying about them being damaged. 

What You Need to Know About Leaving Paint in HVLP and Airless Sprayers

They are also capable of spraying a heavier paint mixture than HVLP sprayers.

No matter the sprayer you are using, best practices require you to clean it immediately and do so properly. 

This will ensure that your sprayer is well-maintained, in top condition, and has a longer lifespan.

However, some situations or scenarios might force you to leave paint in your sprayer. 

If this or a similar situation arises, it does not mean you put your sprayer in a nice corner and return later. You have to be mindful of some of the things outlined below.

  • Drop your sprayer’s pressure.
  • Put the dump and intake tubes in a bucket of water.
  • Turning the halfway should help prevent the paint from drying.
  • Close the lid and also put the sprayer in the bucket of water.
  • Put the dump and intake tubes in a bucket of water.

Consequences of Leaving in the Sprayer for a Prolonged Time

Some of the problems that can arise from leaving paint in your sprayer for longer than the recommended time include the following:

  • Voiding the warranty: Most manufacturers do not cover repairs or replacement if the damage was caused by leaving paint inside.
  • Sprayer problems and malfunction: The sprayer may develop problems, especially the nozzle. It may stop working altogether.
  • Paint cannot be reused: If the paint thickens or hardens, you may not be able to use it or have to dedicate more time and resources to use it again. You’ll have to clean the dried paints off the sprayer and unclog it nozzles carefully to make it operational.

Step-by-step instructions for cleaning your paint sprayer after use

Here are the steps to follow when cleaning your paint sprayer after use:

  • Engage the trigger lock.
  • Switch off the sprayer.
  • Move the pressure to the lowest control setting.
  • Trigger the sprayer to release pressure and then engage the trigger lock.
  • Move the prime valve to the drain or prime position.
  • Take out the sprayer’s filter assembly assembly and put it back with no filter.
  • Take out the switch tip and guard.
  • Use flushing fluid (paint thinner, water, etc.) to clean the filter, switch tip, and guard.
  • Take out the siphon pipe and put it in a flushing position.
  • Keep the prime valve in the horizontal position and switch the power on.
  • While holding the sprayer on a pail, engage the trigger and increase the pressure until you see the flushing fluid coming out.
  • Put the sprayer on a flushing pail and hold it against the pail. Go on and trigger the sprayer so it flushes the system, and release the trigger and engage the safety.
  • Move the prime valve to open and let the flushing solution circulate for 2-3 minutes so it cleans the drain tube.
  • Elevate the siphon tube and turn on the sprayer for at least 30 seconds to remove the flushing fluid.
  • Turn off the sprayer.

Precautions When Using a Paint Sprayer

Some precautions to take when using a pain sprayer include:

  • Wear safety equipment.
  • Avoid operating the sprayer close to the fire and electrical hazards.
  • Follow all the safety instructions outlined by the manufacturer.
  • Always use a sprayer in a ventilated area.
  • Clean the sprayer after using it.

FAQs – Leaving Paint in Airless Paint Sprayers

How long should the paint in the airless paint sprayer sit before I have to remove it?

The paint can be left for up to 3 days for many sprayers. However, leaving paint in an airless sprayer should not be a habit, something you do if you do not have any other choice. As stated above, a good example is if you must return and continue using the paint left in the sprayer after a few hours or the next day.

Should I attach the sprayer hose when leaving paint in my airless sprayer?

I recommend covering the hose with a plastic wrap or damp cloth. You may also leave the drain and suction tube in the paint can. Also, you should ensure that you release the pressure from your sprayer.

What problems can occur if I let the paint sit in my sprayer for a long time?

The sprayer may start developing problems, especially the gun’s nozzle. It may stop working altogether. Also, if the paint thickens or hardens, you may be unable to use it or have to dedicate more resources and time to use it again.

Is leaving oil-based paint in my paint sprayer causing damage to it?

If you do not leave the paint for more than the recommended 3 days, there is no reason why it should cause damage to your airless sprayer. However, leaving oil or oil-based paints for longer will cause more damage to the sprayer than latex water-based paint.

Can I leave paint in the sprayer between coats?

Yes, you can let paint sit in the sprayer between coats. However, leaving the airless sprayer and the intake in a water bucket is important. In most situations, you should be able to paint the next coat within a few hours or a day. 

Content Summary – Leaving Paint In The Sprayer

While leaving paint in your airless sprayer is not recommended, sometimes you may have no choice but to do so. 

However, if you have to leave it this way, you must take the necessary precautions to protect your sprayer from damage. This is important, especially because a great sprayer is costly.

Follow the precaution outlined in the post, and read the manufacturer’s instruction manual to ensure your airless sprayer remains in top condition for longer.

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