There are many questions people ask when it comes to exterior and interior painting. But most people overlook this question:<\/p>\n
How long does paint stay last? Or how long can excess paint remain in the can before it goes bad and is unusable?<\/p>\n
Gallons of paint can be stacked up in the garage or shed for longer than you\u2019d like to acknowledge.<\/p>\n
Knowing how your store mixed the paint will be the key to how long it lasts. When it is stored in perfect conditions, paint will last several years up to a decade. However, it should be a full gallon of paint that was never opened.<\/p>\n
An opened can, sealed improperly or subjected to impurities might only last a few months.<\/p>\n
Here is a general guideline to how long paint will last:<\/p>\n
Latex or Acrylic-Latex Paint –2 to 10 years
\nOil-Based Paint –2 to 15 years
\nChalk Paint –1 to 5 years
\nMilk Paint –1 to 7 days<\/p>\n
The manufacturers of paint estimate their shelf life conservatively. PPG and Glidden both suggest their latex paint, unopened should last two years. Sherwin-Williams and Behr each quote: about a year. Most experts, outside of the manufacturers, say well preserved paint can be shelf stable for up to 10 years.<\/p>\n
Oil-based paints have a similar shelf life. Because the paint has solvents included, it can last even longer if it\u2019s stored properly and preserved well. Some experts say up to 15 years.<\/p>\n
Again, manufacturers are more cautious with their estimations, but most agree chalk paint will last a year. Because of the chemical makeup of chalk paint, it could last for several years. The paint is made not to film over, but you could run into a thickening issue. If that happens, try adding a small amount of water to correct the consistency.<\/p>\n
Milk paint is made from milk proteins. Naturally, they will break down fairly fast. The paint, when left at room temperature will break down within a couple of days. If you refrigerate it after use, you\u2019re still only going to get a week at best. The dry pigment, as it arrives to you, could last indefinitely if it\u2019s stored in a cool dry place.<\/p>\n
Use your nose. If the paint smells off, sour or foul, it\u2019s bad. Some will produce a mildew or mold smell. Anything less than the expected chemical smell of paint should give you cause for concern. Smells mean you should discard the paint and start over.<\/p>\n
If your paint has been stored where it could have frozen and thawed, proceed with caution. Some paint companies say that freezing is not an issue, as long as there is no pungent odor. Others say that once it\u2019s frozen and thawed, adhesion can be affected or consistency off. This gets more true if you know the can has repeatedly frozen and thawed.<\/p>\n
Paint is made to produce a film to dry. Sometimes the gallon will form the film on top of the paint in storage. If there is any more than a film on top, like lumps or solidness, get rid of it. Paint with chunks in it cannot be rectified.<\/p>\n
Jellied paint is always bad. This is a sign that the paint has gone from liquid to something else entirely. Anything less than a shiny liquid needs to be tossed.<\/p>\n
Want to preserve your paint like the pros? Here are their suggestions to get the longest shelf life from paint:<\/p>\n
Store paint in a cool, dry place where temperatures will not dip below freezing.<\/p>\n
Avoid all extreme temperatures, high and low.<\/p>\n
Do your best to keep impurities out of the paint. This includes things like dirt, grass or leaves.<\/p>\n
Transfer your paint to a plastic, sealable container that is made for this sort of storage. This will keep rust from getting into the paint.<\/p>\n
Before you seal the gallon, place plastic wrap under the lid before you seal it. Use a rubber mallet to hammer the lid down. Try not to dent the can.<\/p>\n