A common misconception in the world of DIY is that if paint spoils or develops a foul odour once opened, stored, and then reused, it must be inherently faulty or of poor quality. In truth, paint spoilage can often be traced to improper handling, poor storage practices, or other external factors unrelated to the product’s formulation. Manufacturers generally provide storage and usage guidelines to help preserve paint quality over time, but these are not always followed as carefully as they should be. Failure to do so can result in unwanted smells, lumps, or even mould growth—problems that do not stem from the paint’s inherent quality.
One of the prime culprits behind spoiled paint is contamination. This typically happens when brushes, rollers, stirrers, or even hands are not completely clean and dry before making contact with the paint. Small amounts of bacteria, dust, or other debris can enter the tin, where they can multiply over time, especially in warm or humid environments. The next time you open the paint, you may be greeted by a foul smell or find the paint has turned lumpy. Consequently, it is essential to ensure all your painting tools are absolutely spotless and thoroughly dried before introducing them to the paint.
Closely connected to contamination is the mistake of reusing the paint tin as a mixing or washing vessel. If any water or cleaning residue is introduced into the tin—perhaps from a roller that has just been rinsed—this can dilute the paint, encourage microbial growth and make the paint smell bad. Instead, it is advisable to pour only the amount of paint you need into a clean paint tray or a separate container. In this way, the main tin remains uncontaminated, and the remainder of the paint is preserved in the best possible condition.
Another key recommendation is to refrain from pouring any unused paint back into the original tin once you have decanted it. Although this may seem economical, the leftover paint in your tray or temporary container may already contain impurities or added moisture and over time the paint may smell bad. Transferring it back into the tin introduces the risk of spoiling an entire batch. Should you wish to keep that excess paint, store it separately in a sealed container to avoid contaminating the primary supply.
Stirring practices can also contribute to paint spoilage. It is best to use a designated paint stirrer or a clean, dry wooden or metal rod to ensure that no debris or moisture is introduced. Thorough stirring can help re-blend any separated components, but only when the tool itself is impeccable. Never add water directly into the paint tin to adjust consistency; this should be done in a separate, clean container if the manufacturer’s instructions allow for thinning. By diluting in a secondary vessel, you protect the original tin from unintended microbial growth and preserve the proper formulation of the paint.
Storage conditions remain a major determinant of paint longevity. Tins should be stored in a cool, dry area where temperatures remain fairly stable. Extreme heat accelerates spoilage, while freezing can cause the paint to separate irreversibly. In addition, sealing the tin as tightly as possible after each use helps keep out air and moisture, preventing both oxidation and the formation of mould or bacteria.
Manufacturers often include precise guidelines for storing, stirring, thinning, and applying paint—along with notes on proper brush or roller maintenance and cleaning. If these recommendations are overlooked, the resulting degradation or odour is unlikely to be deemed a manufacturing fault. In essence, when paint has been spoiled by contaminants, poor storage, or improper handling, the responsibility rests with the user. Of course, if you have followed all procedures correctly and still find the paint in poor condition, it is advisable to contact the manufacturer. However, in many instances, diligent adherence to best practices -such as using clean tools, sealing tins tightly, and storing paint in a stable environment—will ensure that your paint remains fresh, odour-free, and ready for future DIY projects.
Find the products you need here…(click), and remember to read the instructions, and to store any leftover product correctly so your paint does not end up smelling bad.
