You can tell paint has gone bad by the smell and texture. A rancid or sour-smelling paint means your paint has gone bad. In particular, the smell of bad paint is similar to sour milk. Other indicators of expired paint include a lumpy or chunky paint consistency.
Aside from consistency or texture, another way to know if the paint's gone bad is just to smell it! If it smells unpleasant or you see mold, you will need to discard it (correctly). And, yes, mold can grow inside a paint can and be a serious health hazard if you put it up on your walls.
Not only can expired paint smell bad, but it could also irritate your skin, nose, eyes, and throat, so it's best to toss it out. If your paint doesn't smell but has an unusual consistency, it can also make your home's paint look like an eyesore.
Expired or bad house paint may exhibit signs such as a foul odor, clumping, separation, or a thick, rubbery texture. Mold growth, curdling, or an unusual color change are also indicators. Always check the label for the recommended shelf life and storage instructions.
Most paints last one to two years in an open can. Latex paints can last an average of 10 years in an unopened can. Oil-based paint lasts up to 15 years in an unopened can. The paint goes bad by hardening or becoming rancid when air or debris gets into a can that isn't sealed well.
For one, the expired paint will have adhesion issues. More importantly, it can be hazardous by giving off excess VOCs or paint fumes. In this case, it's best to get new paint. However, the paint may still be good if the water has separated from the solids.
Oil based paints have a shelf life of anywhere from 2 to 15 years. Depending how well it was sealed and stored. One of the best ways to tell if your stored paint has gone bad is to test it on a piece of board or timber. If lumping occurs it could be that chunky sized bits of paint have formed despite a vigorous stir.
We've got the scoop on why old paint smells so bad and it is simply a buildup of bacteria and mould that causes it to smell like sour milk (OR MUCH WORSE). Bacteria sometimes gets into the paint from the manufacturer but it is most likely to becomes contaminated once opened.
The bottom line is that watery paint is unusable. So if your paint is too watery and you attempt to use it to paint your home, you will notice that the paint won't adhere to surface correctly. It will be 'thin' and therefore will perform poorer than expected.
So, if you notice a rancid smell, you must dispose of the paint. Consistency: paint develops a jelly-like and lumpy texture when it expires. So, when you open your paint tins, mix them with a stirring stick. If you find lumps in your paint, it's not useable, and you need to get rid of it.
Employ Agitation Techniques. Employing a brush or a specialized paint mixer can evenly redistribute the pigments and mediums in dry paints, bringing them back to life. Art Hack: Test the archival quality of revived paint by applying it to a test surface and checking for changes after a week.
“We do not have expiration dates on [Sherwin-Williams] paint but we do give it a shelf life of three years (most architectural coatings) from the time of manufacturing,” says Sherwin-Williams' Director of Product Excellence Dennis Fiorilli.
Conclusion. To sum up, it is generally okay to paint over old paint as long as you prepare your surface correctly.
Recycling Your Paint
Sherwin-Williams is pleased to volunteer many of our stores as drop-off locations. Ready to drop off your leftover paint? Search for a Sherwin-Williams store* in any of the participating states/jurisdictions.
Paint Shake and Re-Tints
If you bring your old paint to a Home Depot paint center, you can have it shaken up in their machines. This saves the effort of stirring up your old paint, but it also sets up another great service: paint re-tints.
You might notice the consistency of your paint has changed. There may be a “skin” on the surface or lumps that won't stir out. If either of these is present, your paint has most likely expired.
How much water? You should add max 10% of water of the total volume of the paint.
After cleaning your painting tool, be sure to let it dry completely before starting your next project! Wet brushes and rollers will dilute latex paint and repel oil-based paint, which could impact your paint color and application.
It won't adhere as well to the surface and will most likely come up patchy when dry. Also off paint can have a sour odour which you might not notice until you have finished painting. If you do use gone off paint you will need to strip off the walls and ceilings where you used the paint and start again.
Both can work, but acrylic paint's elasticity and resistance to wear and tear make it better for high-touch areas and furniture. Latex paint works well for larger indoor projects where low toxicity and easy cleanup with a brush are priorities.
In most cases, an opened can of paint lasts between two and five years. If stored carefully, it may last even longer. However, the storage environment, temperature changes and other factors can impact the shelf life.
Shelf life under normal conditions is two years unopened. Partially used cans might develop skinning if not tightly sealed.
With our wide selection of paint by Sherwin-Williams, HGTV Home® by Sherwin Williams, Valspar® and STAINMASTER™, your perfect color is waiting for you.