If you hit a tennis ball into the bushes and then discover it a year later, you know it will not bounce very well. It’s probably going to look pretty different too.
Air (pressure) has gone out of the balls over time. They will also be exposed to the effect of weathering. This is when they become damaged and discolored due to long exposure to the atmosphere.
But what about if the ball can remain unopened or perhaps opened but not played with?
Tennis balls do expire. If they are opened and just remain in the can, they will still lose pressure. Even if kept in a sealed can, they will not maintain their quality forever. Balls in sealed, pressurized cans are regarded as having a shelf life of around 2 years.
There are a few things you can do to increase the longevity of tennis balls. I will be sharing one way you can do so later on.
In this article I will be covering:
- How long tennis balls will stay good for once the can is opened
- Whether unopened tennis balls can last forever
- Whether the bounce of an expired tennis ball can be restored
How Long Do Tennis Balls Last Opened?
Even if the balls are not played with, several factors impact how long they will last.
The first is location or climate. If the opened tube of balls is kept indoors and in an insulated home, you can expect to see a noticeable loss of pressure after just one week.
What about if you left them in the car overnight? I will use my own experience, but this is an extreme example.
Right now, I live in northern Norway. In the winter, temperatures can drop as low as 5ºF (-15ºC).
If I leave the balls in the car overnight, the cold weather will cause them to lose their bounce very quickly.
The few times I have left them in the car overnight, they have been virtually unplayable the day after. I would describe it as not far off hitting a rock.
Of course, if you live in a warm place like Florida, this is far less likely to happen. It is nonetheless an excellent example of the effects the climate has on tennis balls.
The second consideration is how much air can escape from the balls. If you pull the metal lid off the tin, take the balls out and leave them on a shelf, they will lose pressure faster.
Even though the metal lid has been removed, keeping them sealed can make there less room for the air to escape. If you are not ready to play with the balls, I would simply advise you not to open them.
The more exposed to the atmosphere the balls are, the quicker they will deteriorate.
Do Unopened Tennis Balls Expire?
You may have thought that because tennis balls are sealed in airtight cans, they will last forever if they are not opened.
The airtight cans have what are called micro leaks. Micro leak refers to a leak so small that it is not possible to notice it. The micro leaks will cause a minuscule loss of pressure. As the leaks are so small, it will take a long time to see the difference.
The balls will not be affected for roughly the first two years after manufacture. After this time, you will notice a difference between the cans over two years old and the ones that are more recently made.
I had a friend who discovered a set of unopened balls from about 10 years ago. This was in 2015, so the balls would have been manufactured around 2005. We decided to play with them and see how they compared.
It was clear that they didn’t bounce as well from the moment we started hitting. After a few rallies, the bounce had already weakened substantially. At this point, we switched back to the newer balls.
Tennis balls last longer in sealed cans because they are designed to trap as much air inside the tube as possible. This trapped air allows the ball to maintain pressure, and thus they bounce for longer.
Can You Restore Bounce Of Expired Tennis Balls?
So, you now know that balls will always last longer when kept in a sealed can. But is there a way to revive the ball once it has lost its bounce?
As of today, it is not possible to revive tennis balls in the same way you do football or rugby balls. You cannot just pump it with more pressure.
The main reason tennis balls don’t have a hole for reinflating is that it would create an imbalance in the ball. It would thus cause the ball to behave differently when in flight. It would likely cause the ball to wobble when in the air.
It’s also important to note that pressure is not the only important quality in a tennis ball. Even if it were possible to repressurize the balls, it’s not possible to repair damaged felt.
The material damage affects the bounce of the ball as the shape is slightly different.
Some products are designed to maintain the bounce of the ball for longer.
One example is the Gamma Revive Tennis Ball Pressurizer (Amazon).
The Gamma Pressurizer stores the balls at 14psi. This is the same pressure level as inside the tennis balls when new.
It would be wrong to say that products like this allow the ball to hold its bounce forever. It is also not true that they could make a flat ball bounce as though it was new.
They can definitely help maintain the pressure for longer by protecting the balls from exposure to the atmosphere.
I have not personally used any pressurizer products. As a coach, I have thousands of balls, and it would take too long to put them all in individually.
However, I do know of a few people who swear by them and go as far as to say that they make the balls feel brand new.
These products also have no consideration for felt damage. They focus solely on preserving the pressure and thus the bounce of the ball.
With the technology available today, no tennis ball can be made to last forever. All will eventually expire.
While there is a small range of products available to help preserve balls, they are far from mainstream.
As for me, I prefer to buy a new set of balls. But what about you? Have you tried any of these pressurizer products? Did you find it made a difference?
Leave a comment below. I’d love to hear your thoughts.