Paint storage throughout the winter demands consistent environmental temperatures and water-tight sealing to prevent lumping, skinning, and freezing. When they freeze, water-based paints lose their colour and adhesion abilities, and the container can even burst under the pressure of the expanded frozen water. Conversely, oil paints thicken, requiring extended periods of strong stirring to return to their original state. For these reasons, paint can become unusable, so it’s essential to ensure your paint storage is adequately protected during the winter.
Best Practices for Paint Storage Throughout the Winter
- Insulate your paint storage space – Maintaining a consistent temperature is much easier when your space is insulated. Any heating solution you’ve implemented to keep the room warm will work much more effectively with the inclusion of wall, floor, and ceiling insulation.
- Keep the cans off the floor – Ensure they are placed on shelves, pallets, or racks to prevent them from touching the ground, which will stay colder, even with insulation.
- Keep the seal tight – If you use your paint during the winter while in storage, ensure the rim is clean and reseal the lid using a rubber mallet to ensure it is water-tight after use.
- Decant Leftover paint – If only a small amount of paint remains in your large can, transfer it to a smaller airtight container to reduce exposure to air and prevent skinning.
How to Seal Paint Cans for Storage in the Winter
- Clean the rim – Debris and dried paint can interfere with the airtight seal of the lid.
- Close the lid with a mallet – To ensure it is tightly sealed.
Why Does Water-Based Industrial Paint Freeze?
Water-based industrial paint freezes because its primary liquid component is water. Water-based paints are the most susceptible to becoming completely unusable when stored incorrectly in the winter, because the freezing point of water is 0°C. When water-based paint freezes, the expansion permanently damages the chemical structure of the paint.
When industrial water-based paint is manufactured, the pigments, binders, and additives are finely balanced to achieve a perfect emulsion. But when frozen, these elements separate and don’t remix properly. This causes the paint to become lumpy, stringy, and gritty, not to mention visually comparable to cottage cheese. No intensity of stirring or shaking will return the paint to its original quality.
At first, the paint may appear normal if you attempt to recombine it. However, the adhesion and colour will still be affected post-freezing. This causes compromised colour uniformity, the inability to properly bond with the surface, and inhibited curing, leading to cracking and peeling.
Does Industrial Oil Based Paint Freeze?
No, industrial oil based paint doesn’t freeze; it thickens. The drying oils used in industrial oil paint have a freezing point of around -20°C, much lower than water-based paints, so it doesn’t solidify. Instead, the molecules of the oils and solvents in the paint move closer together, slowing the liquid down and altering the viscosity of the paint.
Think of oil based paint like honey. At room temperature, honey is thick but pourable. When warm, it simply spills from the container. But honey becomes very difficult to pour when cold, as its viscosity is much higher. The same concept applies to industrial oil based paints, so they must be kept at a stable temperature during colder months.
Unlike water-based paints (which are practically unrecoverable after freezing), the thickening of oil paints from freezing temperatures can be reversed. This is because the change to the paint is only physical, not chemical, like it is with water-based paints. Unless oil based paint has been exposed to extreme temperatures for prolonged periods, it can be gradually warmed and stirred to restore it to its normal consistency.
How to Store Industrial Paints Throughout the Winter
Maintain a temperature-controlled environment, referencing the paint manufacturer’s data sheet for the ideal storage temperature. Controlling the environment in which your paints are being stored doesn’t just relate to the air; it also extends to the temperature of the surface your paints are resting on. Storing paints throughout the winter applies to every aspect of the room, including the insulation in the walls, floors, surfaces, and ceilings.
What is the Ideal Temperature to Store Industrial Paint?
The ideal storage temperature for most industrial paints is between 10°C and 30°C. But you should reference the manufacturer’s data sheet to be sure. Formulation differs paint-to-paint, especially between water-based and oil-based variations, so some will be more sensitive to freezing than others.
Does Humidity Affect Industrial Paints?
Yes. When improperly sealed, high humidity can cause your paint cans to rust, encourage the paint to absorb excess moisture, and promote quality degradation. Conversely, low humidity and inadequate sealing cause the solvents within your paint to evaporate and affect the solubility of the paint’s components, leading to separation and layering.
So, the ideal relative humidity for paint storage that maintains stability and longevity is between 40% and 60%.
Why is it Important to Seal Paint Cans Properly?
Sealing your paint cans properly is crucial before you store them over the winter. Humidity and air are the destroyers of balanced emulsification. When exposed to it, the paint develops a dry film, becoming more viscous, chemically degrading, and even expiring.
Does Paint Go Off?
Although industrial paint has no strict expiration date, it can go off. This occurs due to improper storage, exposure to the elements, or long periods without use. Water-based paints can freeze and spoil through bacterial growth, and oil paints are susceptible to forming a hard skin if exposed to air for too long. Proper sealing and a consistent temperature in your storage environment will help to deter degradation and extend the shelf life of your paint.
You can tell if your paint has gone off in a few ways:
- Smell: Expired paint smells pungent and sour, similar to sour milk, indicating bacterial growth.
- Consistency: The paint resembles cottage cheese and won’t incorporate.
- Separation: Some separation is usual, but if distinct layers form, they won’t mix back together.
- Skin Formation: Expired paint develops a thick, rubbery skin, signaling spoilage.
Industrial Paint for Sale at BC Paints
If your industrial paint has degraded over the winter, browse our stock at BC Paints. We are leading manufacturers and suppliers of industrial paint, based in the Midlands, delivering to customers across the UK. We offer everything, from industrial to floor and marine and home paints, all manufactured to BS 381C and 4800.
With bulk discounts for trade and fantastic customer service, we can ensure you have a ready supply of paint for your application within as little as a day. Contact us today to speak with our experts and get recommendations for replacing your degraded paint.
