How can you tell if paint is bad? Rancid- or Sour-Smelling Paint
After the lid is opened, some paint might have a sharp smell: rancid, foul, or sour. Other paint might smell like mold or mildew. If the smelly paint is applied, the smell may lessen but not disappear. Bacterial growth is the driver behind this smell.
How do you know if old paint is still good? Determine if the paint is still good
Latex has a shelf life of 10 years. If it has been subject to freezing, it may not be usable. Test by stirring and brushing onto newspaper. If there are lumps, the paint is no longer good.
How long can you keep leftover house paint? A previously opened can of paint lasts 5 years on average if properly sealed and stored. Old paint shelf life can also vary among different types of paint. In particular, an unopened can of latex or acrylic paint lasts up to 10 years.
Does indoor house paint expire? When properly sealed in a container, oil-based paint boasts the longest shelf life of any type of paint. A can that’s been opened and properly resealed may easily last a decade in storage, while unopened paint can last up to 15 years.