The internal pressure of a new tennis ball is NOT 14psi, it's 26.7psi. The atmospheric (open air) pressure is 14.7psi, so if 14psi can do the trick, how come balls LOSE their pressure if left in the open air, despite the higher pressure in the open air????? The answer is that, as mentioned, the internal pressure is much higher, it's 26.7psi, as can be easily confirmed on the Net. And why other similar solutions use 30-32psi pressure inside their pressurized container.
You put 14psi into the bag with balls lower than 14psi. How can it repressure the ball to 14 psi? I believe you have to put higher psi into the bag to make the balls into 14psi? That’s the maximum available psi can I pump into the bag?
I have 3 of these and it's saved me a god darn fortune on balls. I can't stand playing with soft tennis balls and this device works absolutely 100% as advertised. the three tubes I own have already paid for themselves many many times over
I have lots of balls and have 15 pressure tubes and just ordered another 3. I have had no trouble with any of them and have opened and reclamped them many times. I have two bags of balls. One bag is in the tubes and the other I use for two or three weeks until they start to soften, and then put them in the tubes and use the one's that come out of the tubes. I pump mine up to 20 psi as the greater the pressure difference between the air outside and the air inside the ball, the quicker the air will be forced back into the ball (retired physics teacher!). If you put very soft balls in the tubes, it will take about 3 weeks for them to be hard again. If you put balls that start as new in the tubes straight after you play and use them again a few days or a week later, pressure is maintained. The time to harden also depends on the ball's brand e.g. Wilson US Open balls restore quicker than Slazenger balls. As air passes from the tube into the ball, the pressure difference decreases so the rate of transfer decreases. I use the pump to check the pressure about once per week and top it back up to 20psi. This reduces the time. The worst thing a tennis player can do is practice with soft balls and play a match with hard new balls that fly off the strings. You get scared to hit the ball and start poking instead of hitting through the ball. Also, playing 'touch' shots with hard balls requires a different impact force to when using soft balls. Keeping your balls in pressure tubes means you are hitting with balls that behave similarly to new ones every time you play.
This is interesting stuff I must say. I have a Box of 70-80 tennis balls and I have my dad feed them to me, I purchase the best balls available but they slowly lose their pressure and my Box of 70 tennis balls has to be replaced around once per year at least and yes all the balls look fine still just they are soft. I have been reading many of the comments here and it seems this concept does work. I can imagine what you say is correct, that the air slowly leaks out of the tennis balls through the rubber and if you store them at high pressure the air will slowly leak back into the tennis ball, Sounds pretty logical. My only issue is I have 70 tennis balls not 8 tennis balls. So I am thinking I get a sealed box that can hold 25 PSI, put a valve on it so I can pressurise the box. So when I finish my tennis practice, I will poor all the tennis balls into the box and seal it and use a small air compressor to pressurise the box, this way I can store 70 tennis balls in one pressurized unit. Then when I am ready to go back to the courts I can simply get all my tennis balls out of the pressurized box and put in my practice box. Thanks so much for this info because I am about to get a ball machine and wanted to use pressurized balls in the machine but I was afraid they would not last. Perhaps this concept of storing balls under pressure is the answer. Either way this is great info so thanks a million and happy hitting everyone. 🎾
HI@@brucesaunders2613 I didn't notice this comment until just now. I ended up getting a Spinfire V2 ball machine and got some pressureless balls. I didn't like the pressureless balls at all, they don't properly emulate a real tennis ball and I found them putting more pressure on my strings and I didn't like that. I put Wilson US Open balls and AO Dunlop balls through the Spinfire ball machine and they were great #Perfect. Yes they slowly go flat from new but not any where near what I was hearing like they won't last at all, I have found them to be great. Another thing those Pressureless balls lose heaps of felt and proper pressurised balls I have found don't lose anywhere near the felt off the ball. Pretty much none after 300 balls. So yeah I am using pressurised balls. I'll do another reply because I am using a different way to re pressurise the older balls.
Bag eventually leaks all over after a while, same thing happens with the replacement. No amount of ironing the ends helps it. Lasted just under a year.
I live in Florida and ordered 3 tubes 2 weeks ago and just received them 2 days ago. I have a bunch of old tennis balls that I want to restore so I put the tubes to test. I hope these tubes will do the job. I'll keep you posted...
You didn't say how long it takes to revive balls. Also why don't YOU sell the pumps too? Become a distributor and make more money and help us at the same time.
I have ordered several of these and I have to say they're legit. I kept using the same tennis balls for months and it was only when the felt start to wear out when I had to change. I bought them as gifts for people and man did it save them a lot of money.
But the PSI (air pressure) inside of the tennis ball will only increase until the air outside of it has the same PSI as the tennis ball does inside. With 8 tennis balls, they will not get even close to 14 PSI. This is a scam. It will only increase their life by 2 days or so. It’s not worth the money.
If the balls have equal pressure to the outside, and you pressurize it to say 20 psi, and it equilibrated to 14 psi inside the balls and in the tube. Then would it still be a scam?
Actually I can actually attest that this works.i played with the same tennis balls for a long time and the bounce is great. The weight of the ball has gone down because of the lost felt but the bounce is still there
In normal use I would expect balls going into the tube to be only slightly lower than ideal pressure. Only a small amount of air would need to move into such balls and so I think it should work just fine. If the balls are a lot below ideal at the start then you would need to pump up the initial pressure in the container to allow for this. A lot of people use such containers and they do work.
would it be possible if i just buy a fat bike tire and cut the middle then put the balls inside then fold both side of ends then pump it up? Is my theory wrong?
So maybe. I am thinking about doing this. It must be a tubeless tire so that the air is around the ball. And tubeless tires have liquid sealant. If you cut the tire then you'll have trouble sealing it. I think the best way to do this is to try to get the tire sealed on the rim without liquid sealant. Maybe have a small protecting cover with small holes (for air) around the balls. The other thing is that normal air (atmosphere) is 14 psi. the tennis ball is twice that. I think this guy is doing everything right, but just not getting his numbers/explanation correct. The psi of the plastic container is showing the difference between the outside and inside air pressure. I think the same is true than of pumping up a bike tire.
That will work if you can fold the ends very tightly so the airs won't come out. I'm planing to buy one of these big tubes in the link! smartstore.naver.com/bktoffroad/products/3617355674
Found myself here after my tin of Slazenger hard court which had only had a few games on them felt a bit lifeless tonight! A good product you have there
Just buy a case of new balls. A year old tennis ball is still a year old and will not keep the pressure for more than an hour of play. Even a new dud ball from a can that exploded during shipping will not keep the pressure for more than a day or 2. If you get three of these and rotate new cans in then you might find it worth it. Cannot expect to use this twice a summer and balls last forever.
Tennis balls start with an inner pressure of 14 psi, lose this inner pressure once out of the can because the normal air around the tennis ball is 0 psi, and the higher pressure air on the inside leaks out through the rubber. The way to restore them is by storing them in PressureBall at a higher pressure - e.g. 22-25 psi. The higher pressure surrounding the ball then "leaks" into the inside of the ball - increase the inner pressure. We only recommend storing them at the higher psi while repressurizing them. Once they're bouncing properly again, just store them at the normal 14 psi, and they'll keep bouncing like brand new balls until the felt wears out. You can read more info here if you like: www.pressureball.com/frequently-asked-questions/#revive
Air naturally moves from a high pressure region to a low pressure region until the pressures are equal. The air in a new ball is at a higher pressure than the air outside the ball so air molecules leak through the microscopic holes in the material that the balls are made from both during impact with the strings and sitting in your tennis bag. A new ball will be soft if you don't play with it for a few months If the pressure outside the ball is higher than inside, air will go back into the ball through the same holes that let it out. Retired physics teacher here. I have lots of tubes and they really do work. However you need to be patient. A soft ball will take about 3 weeks to become hard again.
