How Long Does Paint Last And Other Things You Should Know
You might want to use that old bucket of paint – but how long does paint last? It’s important to know the lifespan of paint before you go dipping into those old opened cans of paint in the garage.
Here, you’ll learn about paint and how long it lasts. We’ll also show you a few things that can harm paint after you store it and a few ways you can preserve paint so it will last longer.
When Does Paint Expire?
Each type of paint is different. Its chemical makeup determines how long it will last. Paint cans are stamped with a manufacturer’s expiration date but can last much longer if stored properly. Its shelf-life is determined by the carrier.
For example, an unopened can of oil-based paint last will last for 15 years. Unopened water-based paint can last up to ten years.
Specialty paints, such as milk and chalk paint, have a lower shelf life.
The tables below show how long paint can last if stored in the right conditions.
|Paint Type||Unopened Lifespan|
|Oil-based paint||up to 15 years|
|Water-based paint||up to 10 years|
|Chalk paint||up to 5 years|
|Milk paint unmixed||up to 2 years|
|Paint Type||Opened Lifespan|
|Oil-based paint||up to 10 years|
|Water-based paint||up to 7 years|
|Chalk paint||up to 2 years|
|Milk paint mixed||up to 7 days|
The best way to extend the life of paint is to reseal its container, making it as airtight as possible. If you can achieve a good seal and store paint in a climate-controlled environment, it will last longer.
Different Types of Paint
There are two types of paint: Water-based paint and oil-based paint.
- Oil-based paint uses natural oils such as linseed oil or synthetic oil such as alkyd to carry binders and pigment.
- Oil and alkyd paints store longer than water-based paints because of the use of solvents. However, most people use water-based paints because they are less toxic.
- Oil-based paint is heavy-duty and resists scratches, fingerprints, stains, and dings. When oil-based paint dries, it forms a hard enamel. This type of paint suits interior and exterior heavy traffic surfaces, such as doors, entryways, and window frames.
- Water-based paints use water as the carrier for pigments and binders. This type of paint has fewer fumes, is less toxic in the home and the environment, and dries faster than oil-based paint.
Most household paint is water-based.
Acrylic latex is the main ingredient of latex paint. It provides a seal on surfaces and is resistant to mold and mildew growth. It is a popular choice for interior and exterior walls.
Latex paint is made of water and has few toxins, making it an eco-friendly paint choice. However, latex paints are more susceptible to freezing and require storage in a climate-controlled environment.
Acrylic paints are composed of an acrylic polymer emulsion that is durable and applies well to porous surfaces. Although it is water-based, it does use more chemicals than latex paint.
This versatile paint is great for interior and exterior paint jobs. Apply acrylic paints to glass, plastic, metal, stone, fabric, and leather.
Chalk paint is latex-based with a fine powder additive which provides a matte, chalky finish. The decorative paint is used on furniture, wood, and metal. People like using it as it creates an aged look on surfaces.
Milk paint is a dry mix of milk protein, clay, limestone, and pigments. The paint is eco-friendly and is 100 percent natural. Milk paint is used as an interior paint. The paint also spoils faster than other paint brands because of its natural milk proteins. Once the paint is mixed, it lasts for up to seven days.
What Makes Paint Go Bad?
Several factors cause opened cans of paint to go bad. Such factors will cause paint to spoil within months. You can make your used paint last for several years with extra care.
Paint develops a foul odor if it has bacteria contamination. Mold and mildew can also form, causing the paint to sour and clump.
If paint smells, it is best to throw it out as the smell can linger on walls and may worsen over time. If mold is present, you can try skimming it off the top and stirring the paint to see if it will come back to a good consistency.
Heat exposure can change the chemical composition of paint, preventing it from bonding to surfaces.
Heat will also dry out the paint to the point of no return. If paint develops a thin film due to heat exposure, remove the skin and mix the paint. Apply the paint to a test area to see if it adheres to the surface.
Water-based paints are more susceptible to freezing temperatures than oil-based paints. Frozen paint can form lumps that you may be able to break down by stirring.
If the paint separates, try to stir it back to life. If it keeps separating after stirring, then throw it away.
Tips On How To Store Paint
Leftover paint can last many years is stored the right way. The main reason paint goes bad is because it’s exposed to air. If you can seal your paint after opening it, the paint can last for five years or longer.
To seal an opened paint can, lay plastic wrap over the can and then tamp the lid back on the can with a plastic mallet to avoid denting.
You can buy a new empty paint can from hardware stores if you have damaged your old paint can or if it has lots of dried paint around the lid.
Another way to preserve paint is to minimize its exposure to bacteria. Use a clean paint stick for stirring and handle paint cans with gloves when opening and closing the lid.
Once you have sealed your leftover paint, store the paint in a location that will not experience extreme temperatures.
If your garage does not have climate control, opt to store it inside your home. An interior closet or under the sink are good storage options.
Frequently Asked Questions (FAQ)FAQ
Does paint go bad?
Paint shelf life varies by type. Cans have an expiration date printed on them from the manufacturer, but the paint can last past the expiration date if properly stored.
How long does paint last in cans?
Storing paint in original manufacturer cans is recommended. An unopened can of water-based paint can last up to ten years. Oil-based paint can keep for up to fifteen years.
How long does paint last in a bucket?
Once you pour paint into a bucket, its shelf life decreases. If the bucket has a lid, the paint can last several months if stored in a climate-controlled location.
Can you use old paint?
You can use old paint if it does not smell, have mold, become lumpy, is too thick, or is separated. You can try to stir old paints back to life and paint a test spot to see if they will adhere to the surface.
Does acrylic paint have a shelf life?
Acrylic paint has a shelf life of about ten years if unopened. Opened cans that are airtight can last for about five years.
Paint Shelf: Conclusion
Unopened and opened cans of paint can last a long time when stored in proper conditions. Oil-based paints tend to last the longest, with up to a fifteen-year lifespan. Water-based paints do not last as long but can still survive up to a decade in ideal conditions.
The key to storing opened paint is to reduce as much air exposure as possible. Reducing air exposure is achieved by resealing and using new empty paint cans. Harsh temperatures and exposure to bacteria will also kill unused paint in a short amount of time.
If you have paint that will expire soon, you can use it on touch-ups around the house, paint old furniture, or use it for crafts.