Old paint can be a great way to save money on a DIY home improvement project. As a mix of chemicals, paint requires proper storage and the right conditions to avoid going bad. If you’re storing cans for future use, you’ll need to think about the best options that will ensure your paint lasts for years and steps you can take to prevent it from spoiling.
To help you, we’ve created this guide on how long paint can last. From opened to unopened cans, let’s explore how long paint can stay good for, reasons it can expire and ways to dispose of these chemicals.
Does Paint Go Bad?
Yes, paint can go bad eventually when it is not properly sealed and stored. Like any other chemically-based household product, an opened can of paint may last up to 10 years with proper care and storage.
While there is no specific formula that determines the day that paint has expired, there are many factors that will determine the shelf life of your paint. These include the type of paint, the container it has been kept in, the climate it was stored in, and much more.
These days, most manufacturers will print an expiration date directly on a can of paint which can give you some idea of whether the product inside is still good. But the sell-by date on paint isn’t as hard and fast as the one on a gallon of milk. You wouldn’t want to drink a glass of milk that expired last year, but paint that is similarly out of date may still be perfectly usable.
How Long Is Paint Good For?
An unopened can of acrylic or latex paint may last up to 10 years, while oil-based products can have a shelf-life of 15 years. With proper storage conditions, opened paint can last between 5 and 10 years, on average. When evaluating whether the product is good or bad, you may need to consider the type of paint
How Long Is Paint Good For Once Opened?
There are many types of paint on the market and their longevity is highly dependent on their formulation. Chalk paint tends to have the shortest shelf life, while oil-based paint has the longest. Latex and water-based acrylic paints fall somewhere in between.
When properly stored and under ideal conditions, unopened chalk paint can be used after anywhere between one and five years have passed since its purchase. Unopened latex or water-based acrylic paint is good for up to ten years, while oil-based may last as long as 15 years.
Once a can of paint has been opened its lifespan can be significantly diminished, as prolonged exposure to air can alter the ratio of liquids and semi-solids. However, when it’s been tightly sealed and stored in a cool, dry place, you can generally expect a can of opened paint to stay good for around two years.
How To Tell If Paint Is Bad?
You can tell if paint has gone bad based on the smell, texture and consistency. Like sour milk, a rancid or sour scent can mean your paint has expired and should be thrown away. Another indication that paint has gone off is the exterior appearance of the can. If the can is bulging or the lid is warped, you’ll know the paint has been likely been infested by microorganisms that are feasting on the paint and giving off gas.
You can also often tell if paint is bad by its appearance. Improperly stored paint will often have visible mold or mildew in the can. In addition to being less effective, moldy paint is a serious health hazard and should not be used anymore.
The final indicator that paint has expired is its texture and consistency. While common for the liquid and solids in paint to separate over time, you can mix these components by thoroughly stirring the contents of the pant can until they blend.
Mixing Old Paint
For the perfect blend, you can take separated paint back to the store where it was originally purchased and have them shake it up for you. Thorough blending is vital for color consistency, so the latter option is crucial if you’ll be using the paint for touch-ups.
It’s important to note that separated paint cannot be salvaged if the contents of the can have frozen and then thawed. This process irrevocably alters the chemical properties of the paint. If you live in a colder climate and have stored your paint in the garage or shed with no form of temperature control, it is likely beyond saving.
Paint that has solidified into a consistency that is lumpy or chunky is no longer good to use, as it won’t properly adhere to a wall. The same goes for paint that exists in a jiggly, jelly-like state somewhere between a liquid and a solid.
The exception to this rule is latex-based paints, as they tend to form a thin skin along the surface when the paint begins to dry out. This skin can be easily removed with a wooden paint stirring stick or by pouring it through a paint strainer. As long as that skin hasn’t infiltrated the rest of the paint, you should be good to go.
How To Store Paint Properly
When storing paint, climate control is far and away the most critical factor to consider. Paint has the best longevity when it’s stored in a cool, dry environment that is insulated against extreme swings in temperature. Generally speaking, you’ll want to keep paint in a room that stays in the range of 60 to 80 degrees Fahrenheit.
Making sure the can is properly sealed is the other key component in paint preservation. Before putting the lid back on an open can of paint, take a few minutes to clean away any extra paint that has accumulated around the lip of the lid for a better fit.
Next, stretch plastic wrap over the top of the can before replacing the lid. This will create an airtight seal that protects against contamination. Finally, use a rubber mallet and tap it around the perimeter of the lid to affix it firmly into place.
How To Properly Dispose of Old Paint
Paint can be incredibly toxic and damaging to the environment when it’s not disposed of correctly. If your paint is still good but you no longer have a use for it, you can donate it to people or organizations who can put it to use. For paint that can’t be saved, try these tips.
Oil-Based Paint Disposal
Oil-based paint is considered hazardous waste, as it is full of chemicals that can pollute water sources and otherwise harm the environment. Fortunately, many communities have collection sites set up where they can collect oil-based paints and other toxic products.
Some municipalities even have designated days where these items can be set out for collection by waste management. Look on your local government website to see what resources are available in your area.
Latex Paint Disposal
Like oil-based paint, latex paint can be dropped off at a recycling center or disposal site. Some areas will allow you to solidify the paints and dispose of them with your regular household garbage.
This process entails stirring together equal parts of latex paint and clay-based cat litter and allowing the mixture to sit and thicken. Within a few hours, the paint will have solidified. You can then throw out the entire can, although you’ll want to make sure to leave the lid off of it.
If your can of paint is more than half full, you can transfer it to a different container for this process. Line a box or trash can with a plastic bag, and then pour the contents of the can. Next, add an equivalent amount of cat litter. Combine the paint and litter thoroughly, and leave the mixture to solidify for at least an hour before disposing of it.
What Are The Dangers of Using Old Paint?
Using expired paint is a bad idea from a practical standpoint alone. Paint that has gone bad won’t adhere well to walls and the color may be off. But aesthetics are not the only reason to avoid using paint that has passed its prime. Using old paint can also be hazardous to your health.
When paint is stored in a moist or humid environment instead of a dry one, poor storage can foster the growth of mold. Mold can cause serious medical complications in many people including headaches, fatigue, and respiratory difficulties. Introducing mold-infested paint into your space is a pretty major health hazard.
Even sealed and properly stored paints can be harmful depending on their manufacture date. We are constantly discovering that materials that were once regularly used in home-building (like asbestos) are quite dangerous.
Paints manufactured before the 1990s often contained dangerous components with the potential to make people ill, including lead and mercury. Oil-based paints manufactured after that time period can also emit toxic fumes if they haven’t been stored correctly.
Is It Safe To Store Paint In The House?
Yes, it can be safe to store paint in the house or indoors as long as you place it in a cool, dry location where the temperature stays above freezing. While sealing the can is crucial, temperature plays a powerful role in keeping paint usable for longer periods.
Outbuildings like sheds and garages don’t provide much in the way of temperature control or insulation, so they are not ideal for storing leftover paint. Keeping it in your home is a logical solution and one that is safe for the most part. The major thing to keep in mind is that paint is highly flammable, so it’s crucial to store it away from heat sources like furnaces that could ignite it.
Basements, closets, and cupboards are usually the best places to store paint in your home because they have a consistent temperature. Wherever you store paint, don’t keep it on the floor as that can cause the cans to rust and degrade. Instead, keep it on a shelf or other elevated platform where it will also be out of reach from small children and pets.