How to Store Paint Correctly

How to Store Paint Correctly

At the end of a painting job, you will often find that you have paint left in the tin. It is rare to have exactly the amount of paint needed for the job and no more. Leftover paint should not be discarded, as it can be useful for future jobs and touch-ups. However, it is important to store the paint correctly to ensure it remains usable.

Many people tend to store excess paint in a garage, shed, or attic. However, this is often not the best course of action, as these areas are prone to very warm temperatures in summer and very cold temperatures in winter. They can also be very damp spaces. These fluctuating extreme conditions are not ideal for paint storage.

Store Paint Indoors

Most paints need to be stored in a dry location where the temperature is between 5°C and 35°C. (Always check the data sheet for the paint you have to verify specific storage conditions). Paint containers need to be stored securely to prevent falls and should also be kept out of direct sunlight. Metal tins should be kept away from moisture to prevent rust.

These specific paint storage conditions mean that garages, sheds, and attics are often not the best places for storing paint containers. These spaces can get very warm in summer and very cold—even freezing—in winter. They can also be leaky, humid spaces, which could lead to metal tins rusting.

The best places to store paint indoors are cupboards, under stairs, in a utility room, or in a specialist paint storage cabinet. In these spaces, paint can be kept at a consistent temperature, out of direct sunlight, and away from moisture and potential damage.

Lock Paints Away

Many paints, especially industrial paints, are classed as hazardous. It is important to keep these products away from children and pets. You should also ensure paints are kept away from food products to prevent contamination.

Paints should be stored in secure locations, ideally with a lock, or out of the reach of children and pets. For professionals, paint storage cabinets offer a safe and secure way of locking paint cans away to prevent damage, theft, or misuse.

Decanting & Labelling

During manufacturing, some paint tins are topped up with a nitrogen gas-filled void, in the space between the paint and the lid. This inert gas helps to prevent expansion and contraction of atmospheric air in the gap between the lid and paint. Nitrogen also preserves paint for longer depending on its formulation.

Once a paint has been opened and used, this gas escapes and is no longer present when you close the lid. Some paints will skin over if the air gap between the paint and the lid is significant. The solution to this problem is to decant the leftover paint into a smaller container to prevent this large air gap. If you are decanting paints or coatings into smaller containers, remember to label the container correctly, with the product name, date, colour code, and manufacturer.

You can also label the container with where the paint has been used, to make it easier to find the correct paint when you need to touch areas up.

Check Shelf Life

Every paint has a shelf life—the amount of time it can be kept in storage before it goes off and can no longer be used. Depending on the paint, this can be anything from six months to two years or more. It is important to check the product data sheet for your paint to ensure that the shelf life for your stored paint has not elapsed. If it has, the paint should not be used as it will likely leave a poor-quality finish.

Please note, if you have an epoxy coating, the product cannot be stored after being activated. These products have a short pot life. After that time, the product is unusable as it is cured. Higher ambient temperatures when mixing the components can also make the pot life shorter.

Steps for Proper Paint Storage

If you have leftover paint from a project, it’s a good idea to keep it for future use. Leftover paint can be handy for touching up scuffed walls or furniture, repainting an accent piece to match, and more! However, storing leftover paint can be challenging: you need to know how to store it, prepare it for reuse, and ensure it’s still fresh. Here are the essential steps for proper paint storage:

1. Choose the Right Container

If the paint can is nearly full, you can reseal it (more on that in the next step). If the can is less than half full, consider transferring the paint to an airtight plastic or glass container. This helps the paint last longer due to the smaller air pocket and makes storage easier. Clear containers are especially useful as you can see the paint colour without opening them.

Options for paint storage containers include Tupperware, empty plastic ice cream tubs, or glass mason jars used for preserving foods. These are perfect for storing leftover paint and you likely have them at home.

Pro Tip: If transferring paint, choose a container that will be filled completely to minimise air at the top, maximising the paint’s shelf life.

2. Reseal the Paint Can Properly

If you decide to keep the paint in its original can, it’s crucial to reseal it properly. Clean the edge of the can and the lid with a dry cloth to ensure a tight seal.

Next, place a piece of plastic wrap, twice the length of the can’s circumference, loosely over the open can. Set the lid on top of the plastic wrap, and use a rubber mallet or hammer to lightly tap the lid’s edges to secure it in place.

Pro Tip: The lid is on correctly when it’s flat, not slanted or bumpy along the edges.

3. Keep the Paint for Future Use

You never know when leftover paint will be useful. It’s great for touch-ups or new projects. Properly stored paint can be reused for various DIY tasks without the need to buy new paint.

How Can I Tell If My Paint is Still Good?

You can usually tell if paint is still usable. Leftover paint typically lasts around two years if stored properly. Open the container and stir the paint; it should reconstitute quickly and be smooth without bumps. It shouldn’t have an unpleasant odour. If there’s a clear film on top or hard or jelly-like pieces, the paint is likely unusable. A rotten-egg smell is also a sign it’s gone bad and should not be used.

How Should I Dispose of Paint?

Latex-based paints (emulsions) are water-based, quick-drying, easy to clean up, and environmentally friendly, making them suitable for a variety of interior and exterior applications. Oil-based paints (gloss), on the other hand, provide a durable, high-gloss finish with superior adhesion, but require longer drying times, solvents for cleanup, and have a higher environmental impact.

If the paint is no longer good, dispose of it safely. For oil-based paints (gloss), leave the container open to dry out, adding strips of paper to speed up the process. Once dry, you can throw the container away or pry out the dried paint to reuse the container.

For latex paint (emulsion), add clay-based cat litter to the open container and wait for it to dry into clumps before disposal.

With these tips, you’re ready to store and reuse your leftover paint for future projects, whether repainting walls, refreshing wooden furniture, or other DIY tasks. Proper storage makes your projects easier and more cost-effective.

Do you have any tips on storing paint correctly? Let us know in the comments below!