How Long Does Paint Last? (Solved! For Opened & Unopened)

Chances are, if you are reading this article, you have an old can of paint that you put in storage ages ago, and you are wondering what the possibilities are of still being able to crack it open and using it.

Depending on the type of paint, whether it is latex or oil-based, maybe chalk or milk paint, lifespans differ. The method in which it was stored will also play a major role in the paint's future usability.

This guide should help eliminate your concerns and give you a definitive answer to the age-old question, “Is this stuff still good?”.

There are a few major factors when it comes to the lifespan of the paint. The first is the variety of paint we are discussing. Additives in the paint can either lengthen or shorten longevity, so we will want to know what we are working with right off the bat. The second major factor is how the paint has been stored.

That old half full, half sealed can of paint that has been out in the cold garage all winter may very well have expired, while the paint you sealed in a jar and put on the shelf in the basement may still be as good as new. Paint needs to be stored in a climate-controlled environment.

Storing paint where it is exposed to extreme cold, heat, or sunlight will change the chemical makeup of the paint ingredients, in turn ruining the paint altogether. Paint also needs to be stored with little exposure to air.

Paint has a substantial amount of water which would evaporate with exposure. For this reason, a properly stored, unopened can of paint could potentially last up to a decade, while an open, partial can could last months, or maybe even a few years. Keep these factors in mind next time you slap the lid back on a can and plan to store it indefinitely.

How Long Does Paint Last In A Can
  • Acrylic Or Acrylic Latex Paint
    Paint with acrylic or latex will have a shelf life of roughly 2-10 years. While this may seem vague, it will all depend on storage conditions. The most well-sealed and temperature-controlled examples will keep for the longest time.
  • With improper storage, with an unsealed container, or in an element exposed setting, these paints could deteriorate and be ruined in as little time as two months.
  • Oil-Based Paint
    Oil-based paints tend to be the longest-lasting, generally due to the ingredients used—lifespan on these ranges from a minimum of 2 years to a maximum of 15 years.
  • The solvents used in oil-based usually tend to be more forgiving and help the paint last longer overall. Like latex or acrylic based though, improper storage could lead to these paints deteriorating in mere months.
  • Chalk Paint
    These types of paint have short lifespans right from the beginning. A typical chalk paint only lasts in storage for a minimum of 1 to a maximum of 5 years in proper storage conditions.
  • There is good news though, Chalk paint just becomes thicker over time and can be thinned with water so that you can use it once again, even after it may seem ruined.
  • Milk Paint
    In its initial powdered form, this paint will last indefinitely as long as it is not exposed to moisture. Once the milk proteins are added, the paint will only last between 1-7 days.
  • Refrigeration will help stretch to that 7-day mark, but that generally is the maximum lifespan for this product. Milk Paint is not recommended to be stored at all if possible.
  • Spray Paint
    Spray paint has its distinct lifespans and storage tolerances. Lifespans vary not only based on storage conditions but also the spray nozzle condition. Spray paint cans do have an expiration date stamped on the bottom of the can, but that usually just gives the consumer an idea of how long the aerosol will last, not the actual paint. 
  • Spray paint itself can last between 2-8 years as long as it is stored properly. Even if the aerosol has left the can, users should be able to decant the paint and spray from an airbrush. The issue usually stems from improper nozzle cleaning before storage.
  • The easiest way to prevent this from happening is to finish the project and then tip the can upside down and release a small bit of the aerosol through the nozzle. This will clear any paint and prevent it from drying inside of the nozzle, which would then need to be unclogged.

How To Know If Paint Is Bad

Using old paint is entirely safe. Cans sometimes have "use by" dates stamped on the lids or bottoms, but this is usually just a manufacturer guideline rather than a definitive expiration. Below is a list of how to determine if your paint is actually bad or still appropriate to use.

  • Has A Foul Or Rancid Smell
    If your paint has gone "sour," it can no longer be used and should be disposed of as per local regulations and guidelines.
  • Has Been Frozen And Thawed
    Paint that has been frozen and thawed can sometimes be used if it has not developed lumps that cannot be mixed back into a liquid state.
  • If your paint has been thawed, remove the lid, use a mixing stick or paint strainer to skim the liquid paint from the semi-solid, discard the material caught in the strainer, and you should be able to mix and use the remaining liquid.
  • Is Lumpy
    Lumpy paint is generally past its lifespan. You could strain the paint through a screen and use the liquid paint, but most often, the clumps of paint you remove contain valuable amounts of additives necessary for the paint to adhere properly to the material you plan to paint.
  • Has Become Jelly-like
    When the paint has become "jelly-like," it has become unusable. This state usually comes from too many heating and cooling cycles while in storage.

How To Store Paint Properly (Tips From A Pro)

Storing paint properly is the best way to ensure longevity. No matter what type of paint you are saving, the same general rules apply.

First, the storage area must be relatively cool. Room temperature is the best. Next, keep paint out of the sunlight; the sunlight hitting the paint in cycles will heat and cool the paint daily, and this will cause the paint to heat up and cool down, which is not ideal in maintaining consistency.

Whether cans are opened or unopened does not change the space that they should be stored in. Even unopened cans are susceptible to heating and cooling-related degradation. If you are storing opened cans of paint, you should transfer the unused portion to a sealed jar. This prevents any possibility of rust from an old can compromising the paint.

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The Correct Way To Dispose Of Unusable Paint

Always wear proper personal protective gloves and glasses when painting. As for disposing of paint, different varieties require different solutions. For oil-based, you will want to research your local government’s policy on hazardous waste. Most municipalities will have a pickup or dropoff calendar where you can dispose of the spray cans and any leftover materials.

For water-based or acrylic paint, remove the lid and place the pint somewhere that the water can safely evaporate and the paint can harden. To aid in this process, you can use cat litter to harden the paint leftover in containers. Once solidified, the cans can usually be placed with regular recyclables for pickup.


How Long Does An Interior & Exterior Paint Job Last?

The material in which you are painting and the environment in which those materials live are usually the main factors affecting paint longevity. Using old paint, as long as it has been determined that the paint is still usable, will not affect the dried lifespan.

Generally speaking, you can expect interior paint, barring extreme climates, to last between 5-10 years before chips, bubbles, or peeling occurs. Roughly the same can be said for exterior paints, 5-10 years before degradation in reasonable climates. Exposure to storms, cold, or sunlight will affect paint lifespan.


Frequent Questions About Paint Lifespan

How long does painted brick last?

Paint on a brick, when using appropriate paint, could last up to 20 years! This will change due to climate and exposure to elements, but bricks have an amazing ability to hold paint.


How long does glow in the dark paint last?

Glow in the dark paint is illuminated by infused phosphors in the paint, which allow it to glow after being charged by UV light. This type of paint can last for up to 10 years before needing a fresh coat to glow again!


How long does paint last on concrete?

Most brands require you to re-apply paint to concrete every 5 years. Concrete that is out of the elements or treaded on less than average may hold paint for up to 10 years.


Can you add water to old paint?

In some cases, such as water-based acrylic or chalk paint, you will be able to add water to thin the paint, either due to it becoming thick over time or to provide more coverage.

Conclusion

Hopefully, this article will solve the riddle of whether or not your old paint is considered good or bad. As long as it has been stored in a sealed container, in a climate-controlled space, and has not been contaminated by rust or air, you should be in good shape! Remember that paint can last up to a decade or longer when stored properly.