A very few of us who don’t have a shed, cellar or cupboard that isn’t full of old tins of leftover paint that have been kept for touch-ups or in case they can be used for other projects in the future! But, if you are anything like the majority of us, these cans of old paint will be gathering dust with their labels fading until you can’t remember what they are when you come to look!
So we get to the question, when you have decided to tackle a new DIY project, how long does paint last? The answer is, like most things, not completely straightforward, as it depends on many different factors. However, paints do have a shelf life, and it is worth understanding the things that will impact that so that you get the best value from your paint!
Below, we have set out some information about the different types of paint and the elements that might impact how long they last. We hope that you find it useful!
Types of Paint
Compass, yardstick, and leftover paint. pic.twitter.com/FlEnzJIxgY
— Gina Biggs / Strawberry Comics (@ginabiggs) May 21, 2022
There are four main categories of paint that you are most likely to have at home from DIY projects: each has a different shelf life and different things that will impact it.
Oil-Based Acrylic Paint
Oil-based or acrylic paints are typically used on woodwork and metal and are thick and glossy and apply smoothly to a surface. Because of the paint’s chemical makeup, it does have the longest shelf life of all the paints. However, because of the oil content in the paint, it is prone to splitting.
So, how long does emulsion paint last? Unopened cans could last for anything up to 15 years, and fully sealed contents, once opened, should last for several years, maybe up to 10.
If they look and smell ok but have separated, oil-based paints will come back to usable paint if you give it a good mix with a paint stirrer. If left open, however, these paints will quickly dry up, so it is crucial to store paint following the instructions on the tin.
Water-Based Emulsion Paint
Water-based paint, or emulsion, is a very common paint to have in the house, as you can use it on walls and ceilings in most home decoration projects. In America, this is known as latex paint, and it has a much lower chemical content than oil-based paint.
If stored properly, in a dry place out of direct sunlight, and safe from extreme temperatures, this opened paint can last for anything between two and ten years. If the paint is repeatedly frozen, it can develop grainy lumps and semi-solids. If the conditions are not too bad, it may be possible to stir the paint until these lumps have disappeared, but if the opened paint has gone bad, it may be time to buy a new tin of paint!
But the good news is that this type of paint lasts for a good number of years if stored correctly.
Milk paint is probably the less well known of paint types, but it is often used on furniture when restoring or reproducing antique furniture. Milk paint is the least well-lasting paint type of paint due to the milk proteins. Old paint is really not worth attempting to use as it doesn’t last beyond a few days unless it is extremely well sealed, perhaps bashed down with a rubber mallet to ensure no air contact. You should keep it in the fridge while you are using it, and you should not store it in a garage or shed.
Chalk paint is often used on upcycling furniture projects and gives a lovely traditional smooth and chalky finish to wood or even metal. It can be layered in different colours and distressed by sanding down.
How long does paint last once opened? Well, typically between one and five years if it is not exposed to the air and the cans are well sealed. The paint can develop a thickened skin which can be let down with water and stirred until it has become smooth again.
Signs to Look Out for That Your Paint Has Gone Bad
So, when you ask the question, does paint go off, the answer is yes. If the paint has been exposed to the air or temperature extremes in your paint store, it may be unusable.
Here are some of the main signs to look out for when you open up old paints for your next paint job.
Opened cans of oil-based paints that have been frozen more than once can become lumpy. One way to protect them from this is to store any leftover paint indoors or cover it in plastic wrap, giving it some protection against the cold.
Yes, paint can acquire a bad odour, and if it does, the paint has likely developed bacteria. Water-based acrylic paints are most prone to this issue, although paint companies are developing anti-bacterial paint, which extends how long paint lasts and protects against this issue.
If your paint smells bad, you don’t want to end up with walls that smell the same, so it is probably time to buy new paint if this happens to you!
So, Does Paint Go Bad?
We will be painting our trash bins this summer to a tri-bin system with recycling ♻️ & compost 🪱. We are upcycling the bins & using leftover paint from the high school. Stoked! pic.twitter.com/mm8ijRgaP6
— Sonia Myers (@sonia_storying) May 19, 2022
If you are starting a new paint job and have decided to look at your old paint or unopened paint in your shed or garage but are wondering, does paint expire? Well, then the answer is yes, but over very different timescales, depending on the type of paint and how it has been stored.
Below we have brought together the main paint types and how long their lifespan is:
- Gloss or acrylic paint – 2 up to 15 years
- Emulsion or latex paint – 2 up to 10 years
- Milk paint – 1 up to 2 years if unopened and in a can. A few days if mixed up from a powder or once exposed to air
- Chalk paint – 1 up to 5 years
There are several ways to extend the lifespan of old paint that are worth following, as it is a great way to save money when tackling your next paint job.
You can use a paint strainer to filter out any flakes or lumps from your latex or emulsion paint, leaving it smooth and ready to apply a fresh coat to your walls.
Stirring an old paint that has split will most likely bring it back together again and make it good for use. Keeping paint at the right temperature and not allowing it to freeze will help prevent lumps. Keeping any chemical-based paints away from extreme heat is also a very important storage tip!
Keep Your Paint Sealed and Stored Safely
So, how long does paint last? By now, you should have all the information about the different types of paint and the elements that might affect how long they last. Paint is an economical product if treated with care and stored correctly in the right conditions, as you can keep it for many years and use it on multiple DIY projects. Even if you find that your paint has an issue and has gone lumpy or split, you will most likely be able to get it back to a usable condition by following some of our tips above.
So good luck on your next painting project, and keep that paint sealed and stored safely!
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Ian loves everything that revolves around the home improvement niche. He loves trying out new home appliances. He has also handled a lot of equipment and has a lot of insight. Plus, he’s worked on various home improvement projects that became a success. If Ian isn’t busy working on his latest project, you can find him reading up about another one!