I Made A Tennis Ball Pressurizer I Think It Works

[WilsonPlayer101]

I made a tennis ball pressurizer from a home water filter housing. My first attempt was with a tennis ball can and a ABS fitting and screw on top. It was not air tight and I was spending a lot of effort and time doing so, so I scrapped it and went with a better design. This new one is successful in holding pressure but I won't know until tomorrow if it successfully charges/pressurizes tennis balls. I am going to play tennis tomorrow at about 4:00 PM PST and I will know if it charged the tennis balls. In theory if it holds pressure then it should charge the tennis balls.

I put the tennis balls in at 2:30 PM PST Friday and pressurized the can to 28 PSI. Today it still holds pressure so it must be air tight. Only draw back to this is I bought a non-transparent water filter housing. If it was clear I could see if the tennis balls implode. I understand that new balls don't implode at over 20 PSI and these were used only once so they should be fine. My understanding is at about 24 to 30 PSI tennis balls can be charged in 3 or 4 days. More later why I chose a solid color rather than transparent.

This was not my idea or design but found this on YouTube. After my first attempt failed I thought this water filter housing is a great concept and should work.

I am not going into how I made it step by step now but if you want to know then just post that you want to know and I will post details.

 

[WilsonPlayer101]

That photo was cut off when I try to put the URL from Photobucket. I don't see at this forum to upload directly but you have to host it somewhere and then put the link in your post. I will try again.

 

[WilsonPlayer101]

Some vids where I got the idea that this could really be done. All are spoken in Spanish and I only know about five words in Spanish so that didn't help. I just watched the vids a bunch of time to figure it out.

I actually had this idea before I watched the vids in Spanish but had the idea from a vid of a guy crushing tennis balls in a water filter housing without the filter in it and crushing it from water pressure. That gave me the idea that a water filter housing may work and I just had to figure out how so I found vids.

This gave me the idea to use a water filter hosuing -

This vid gave me a good idea how to make it.

Another

 

[WilsonPlayer101]

It holds 4 tennis balls but for the first test I only put 3 in. These three came from a can of 4 Dunlop balls so maybe I should have put all 4 in. These Dunlop were good on the court and were about $3.15 after tax.

I don't teach tennis nor have a ball machine so I don't need a lot of tennis balls at one session. If I needed many at once maybe I would do the beer keg method or paint pot method but 3 or 4 are plenty at once. I can easily afford a new can every other time I play but I made this to see if it worked and also seems right to get more life out of a ball than just one time. When we play, my friend and I buy new tennis balls and alternate between who buys a new can. In reality we can use one can twice even without buying a new can but we don't and get a new can each time so it will be interesting if this pumps up the balls like new. As long as the felt is good and they can be recharged then I am doing this.

 

[antony]

I have a gaxco ball saver and I like it

 

[princemidplus]

I'd like to know what balls you use that keep their felt intact. I've used slazenger, dunlop, pro kennex and wilson and I find that after 3 sets of singles the balls are pretty much finished as the felt has worn right down. The pressure in the balls is still ok but the balls play like little rockets which are hard to spin anymore. It has never been worth my while to even consider repressurising a tennis ball that has little felt left on it

 

[WilsonPlayer101]

I have a gaxco ball saver and I like it

I had one but didn't have much luck with it.

How long do you keep the balls in it? I didn't notice any signifigance in bounce so I gave up. How many times do you use it until you start over with a new can when you play?

 

[WilsonPlayer101]

I'd like to know what balls you use that keep their felt intact. I've used slazenger, dunlop, pro kennex and wilson and I find that after 3 sets of singles the balls are pretty much finished as the felt has worn right down. The pressure in the balls is still ok but the balls play like little rockets which are hard to spin anymore. It has never been worth my while to even consider repressurising a tennis ball that has little felt left on it

Well, if this does work to pressurize the tennis balls I only plan on using the tennis ball set 4 times. The initial use when the balls are brand new then recharge (pressurize) them three more times and start with a new can. I play probably less than most people at this forum. I read about people here play for hours at a time, play best of 3 or best of 5 sets. I only play once a week for maybe an hour. Warm up for 20 minutes then play 1 set. I don't have the time to stay out hours at a time. When we are done the felt is still good. Bounce is fine but we get a new can every week just to have tennis balls that bounce new. I think after using them once the ball still bounces well but after waiting a week between sets the bounce is not as good so if I can pressurize them between weeks it may be helpful. They aren't dead between weeks but they just don't bounce so great.

The balls I buy usually are Penn or Wilson for under $3.00 after tax so economically I can easily afford new balls every other time playing and my friend can too. The felt on those are good out of the can. I did try "Flare" by Wilson that are red and at the get go those have little bounce and bad felt but maybe I just got a "dud".

So why do this? I guess I was intrigued by pressurizing tennis balls and from a scientific stand point I just did this to see how well it works but in the end if it works I might as well try to get more life out of the balls. That makes sense since I made it I should use it.

Doing a search for Pressurizing Tennis Balls here at TT there seems to be a lot of interest here for this. So many people are on the quest to do this.

 

[princemidplus]

Well, if this does work to pressurize the tennis balls I only plan on using the tennis ball set 4 times. The initial use when the balls are brand new then recharge (pressurize) them three more times and start with a new can. I play probably less than most people at this forum. I read about people here play for hours at a time, play best of 3 or best of 5 sets. I only play once a week for maybe an hour. Warm up for 20 minutes then play 1 set. I don't have the time to stay out hours at a time. When we are done the felt is still good. Bounce is fine but we get a new can every week just to have tennis balls that bounce new. I think after using them once the ball still bounces well but after waiting a week between sets the bounce is not as good so if I can pressurize them between weeks it may be helpful. They aren't dead between weeks but they just don't bounce so great.

The balls I buy usually are Penn or Wilson for under $3.00 after tax so economically I can easily afford new balls every other time playing and my friend can too. The felt on those are good out of the can. I did try "Flare" by Wilson that are red and at the get go those have little bounce and bad felt but maybe I just got a "dud".

So why do this? I guess I was intrigued by pressurizing tennis balls and from a scientific stand point I just did this to see how well it works but in the end if it works I might as well try to get more life out of the balls. That makes sense since I made it I should use it.

Doing a search for Pressurizing Tennis Balls here at TT there seems to be a lot of interest here for this. So many people are on the quest to do this.

I definitely see the benefits of doing this if your felt lasts longer than you play for. I tend to play at least 3 sets of singles when I play. Maybe 2 with a long warm up. I also only play on hard courts so the court tends to rip the felt off especially if dusty. Thus I've never had the need to pressurize my own tennis balls. Balls cost more here in south africa too. I'd be keen to see if this works and as I can buy second hand balls at my club that the social oldies have used for a few games and are almost like new except for the decreased pressure

 

[WilsonPlayer101]

This is sort of like the Gaxo but with a valve to pump it up. Someone on TT had a Gaxo or similar and added a valve to pump it up.

 

[WilsonPlayer101]

I definitely see the benefits of doing this if your felt lasts longer than you play for. I tend to play at least 3 sets of singles when I play. Maybe 2 with a long warm up. I also only play on hard courts so the court tends to rip the felt off especially if dusty. Thus I've never had the need to pressurize my own tennis balls. Balls cost more here in south africa too. I'd be keen to see if this works and as I can buy second hand balls at my club that the social oldies have used for a few games and are almost like new except for the decreased pressure

Today when I play I will see how well this device works and report back. I guess I just get curious how and if things work so I did it.

 

[WilsonPlayer101]

Here is an interesting video considering pressure loss and how a pressurizer can keep the balls pressure at the right level or can increase it. But yes you are right, the felt health is equally as important.

 

[antony]

I had one but didn't have much luck with it.

How long do you keep the balls in it? I didn't notice any signifigance in bounce so I gave up. How many times do you use it until you start over with a new can when you play?

I had one but didn't have much luck with it.

How long do you keep the balls in it? I didn't notice any signifigance in bounce so I gave up. How many times do you use it until you start over with a new can when you play?

I use US Open balls at the moment and playing at a 3.5 level I just use them for 2-3 days then I open up a new can.

 

[WilsonPlayer101]

I use US Open balls at the moment and playing at a 3.5 level I just use them for 2-3 days then I open up a new can.

Yeah my plan is to use them 4 times then get new balls but I may just use 3 times but all depends on how well this device works and how well the felt lasts.

 

[WilsonPlayer101]

Another video that inspired me to do so. I don't understand him but I am under the impression this works for him and he is happy with his pressurizer. He seems to be from Spain. Looks like a nice old man -

This is what got me on this kick to make a pressurizer. I watch many Tennis vids on YouTube and YT suggested this vid to me. It opened my eyes to pressurizing tennis balls with a sealed device with pumped air into it. From watching this I did a lot of research. I think this guy is from New Zealand. Before this I had no idea a device can be made to pump up with air and pressurize the tennis balls. I thought only screw on pressurizers were made. From research I found that this guy offers great customer service if you have problems with his tube. He is responsive.

 

[antony]

Yeah my plan is to use them 4 times then get new balls but I may just use 3 times but all depends on how well this device works and how well the felt lasts.

It’s just nice knowing I’m not wasting the balls when I open a fresh can and play just a little bit with them

 

[PrinceMoron]

I won a ball pressuriser at some tournament but it only held 3 balls, which may be ok if people but 3 ball tubes in your neck of the woods.

 

[Pctopcool]

Many people actually missed an important point which is ambient air temperature. For ideal gas, P=rho*R*T. So, even you pressurize the ball to your target pressure, if the temperature change, the internal pressure will be very different.

For example, I just opened my corny keg, which was pumped up during the coldest winter month. The bounce from these pressurized balls made me feel like playing with Nadal.

 

[Injured Again]

Well, if this does work to pressurize the tennis balls I only plan on using the tennis ball set 4 times. The initial use when the balls are brand new then recharge (pressurize) them three more times and start with a new can. I play probably less than most people at this forum. I read about people here play for hours at a time, play best of 3 or best of 5 sets. I only play once a week for maybe an hour. Warm up for 20 minutes then play 1 set. I don't have the time to stay out hours at a time. When we are done the felt is still good. Bounce is fine but we get a new can every week just to have tennis balls that bounce new. I think after using them once the ball still bounces well but after waiting a week between sets the bounce is not as good so if I can pressurize them between weeks it may be helpful. They aren't dead between weeks but they just don't bounce so great.

The balls I buy usually are Penn or Wilson for under $3.00 after tax so economically I can easily afford new balls every other time playing and my friend can too. The felt on those are good out of the can. I did try "Flare" by Wilson that are red and at the get go those have little bounce and bad felt but maybe I just got a "dud".

So why do this? I guess I was intrigued by pressurizing tennis balls and from a scientific stand point I just did this to see how well it works but in the end if it works I might as well try to get more life out of the balls. That makes sense since I made it I should use it.

Doing a search for Pressurizing Tennis Balls here at TT there seems to be a lot of interest here for this. So many people are on the quest to do this.

A few random thoughts. The felt on premium balls tends to last a **lot** longer than on lower tier balls. When I practice with my son, we are basically going non-stop for the entire 90 minutes, and start another rally within a couple of seconds of when the previous one finishes. We both hit hard, with a lot of spin, and both of us use shaped strings. We will typically use two cans and even so, the felt on lower tier balls won't last two sessions or three hours. Two cans of the US Open balls are still playable after three sessions, though by that they start to lose their pressurization throughout a session and also start playing noticeably slower, like that the rubber has work hardened and is absorbing more energy from being hit or when bouncing on the ground.

Second thing is that here in the Pacific Northwest, a majority of our courts are indoors and they're pretty fast as well. Those of us who are tournament players and want to compete in places like southern California on slow outdoor courts, using repressurized balls works well because as they slow down but still retain their bounce, it's a good substitute for practicing on slower courts that we don't have.

Lastly, I purchased a PressureTube about 18 months ago. It's great for maintaining pressure but doesn't work well to repressurize balls because it can't survive the higher pressures to allow that to happen in a short timeframe. About 20 PSI is all it can take. Mines sprung a leak from two places right at the one year mark and I emailed the manufacturer to ask some questions, and got nothing in response. There was a leak in the plastic encapsulating the base of the schraeder valve, and another one at the bottom opening where the plastic is heat sealed.

 

[WilsonPlayer101]

Okay I played a set. I am happy to report back that it worked. The bounce in the ball was well preserved with member Injured Again saying premium balls felt lasting longer I think I will buy those from now on because I do feel the felt on these are not as good as I would like. I usually buy Penn or Wilson for $2.96 after tax. I think spending more on premium balls will be a better choice if I am going to recharge balls. I will buy US Open balls as he does. Sorry to hear your Pressure Tube has problems and they haven't responded.

Here is a guy who made his own. In comments I think he said it works but the tube gets worn out after awhile -

 

[WilsonPlayer101]

Okay I recommend anyone wanting to reuse balls two or three or maybe more by pressurizing them make what I did. It isn't hard. If you want detail just ask and I will post.

One thing I want to mention is that I have a solid color filter housing because I saw the transparent ones at Home Depot about ten miles from home when I was doing errands in that area but I was unsure if I would be making one. Next day I went to HD by my house and they had the solid white one and I so happened to find the plugs I needed so I was so excited about that I just bought the white one. That location was out of transparent ones. No regrets since it works.

 

[antony]

Okay I recommend anyone wanting to reuse balls two or three or maybe more by pressurizing them make what I did. It isn't hard. If you want detail just ask and I will post.

One thing I want to mention is that I have a solid color filter housing because I saw the transparent ones at Home Depot about ten miles from home when I was doing errands in that area but I was unsure if I would be making one. Next day I went to HD by my house and they had the solid white one and I so happened to find the plugs I needed so I was so excited about that I just bought the white one. That location was out of transparent ones. No regrets since it works.

If you’re just reusing a can or two worth of balls, why not just use the Gaxco tennis ball saver for $17 each. I keep mine in my bag. The tubox you linked seems kind of annoying and bulky. I’m already annoyed with twisting my gaxco tube lol

For those that reuse balls with machines I can understand taking the time to build a large pressurizer

http://tt.tennis-warehouse.com/index.php?threads/large-tennis-ball-pressurizer.657879/

 

[Raul_SJ]

Okay I recommend anyone wanting to reuse balls two or three or maybe more by pressurizing them make what I did. It isn't hard. If you want detail just ask and I will post.

So what is the bottom line, after playing three sets one day, it can be used two days later and opponents will not notice a difference. Almost as good as new?

 

[Injured Again]

So what is the bottom line, after playing three sets one day, it can be used two days later and opponents will not notice a difference. Almost as good as new?

No, two days is not quite enough in my experience to restore once used balls to new bounce conditions. It takes more like 3-4 days at 30-32 PSI, and then even if the bounce is as high as new, the balls come off the string and off the court more slowly the more they are used.

That being said, third time used US Open balls still play better and more consistently than brand new Penn Championship balls.

 

[Raul_SJ]

That being said, third time used US Open balls still play better and more consistently than brand new Penn Championship balls.

Has there been a factory change with Penn balls? Opponents would sometimes bring Penn ATP Tour and the balls were great -- probably better than Wilson US Open. Think the name was then changed to Penn Marathon.

 

[louis netman]

Please find me a pressurizer that can do 250 balls...
And I don't want to load them into the charger one by one...

THX!

 

[antony]

Please find me a pressurizer that can do 250 balls...
And I don't want to load them into the charger one by one...

THX!

There are DIY guides all over the internet. Make sure your seals are good

http://tt.tennis-warehouse.com/index.php?threads/large-tennis-ball-pressurizer.657879/

 

[Pctopcool]

Has there been a factory change with Penn balls? Opponents would sometimes bring Penn ATP Tour and the balls were great -- probably better than Wilson US Open. Think the name was then changed to Penn Marathon.

I think penn ATP became penn tour, since Dunlop won the ATP sponsorship. Some people found penn tour is slightly different than the old penn ATP. Propenn marathon has been the same forever iirc.

 

[WilsonPlayer101]

If you’re just reusing a can or two worth of balls, why not just use the Gaxco tennis ball saver for $17 each. I keep mine in my bag. The tubox you linked seems kind of annoying and bulky. I’m already annoyed with twisting my gaxco tube lol

For those that reuse balls with machines I can understand taking the time to build a large pressurizer

http://tt.tennis-warehouse.com/index.php?threads/large-tennis-ball-pressurizer.657879/

Reason is I had one but I was never successful with it restoring the bounce in the balls using that. I tried and it didn't work for me then a few years later same thing. In theory it should work seeing it makes the pressure in the device 14 PSI which should pump pressure into the balls. It works for you and other people but I never noticed a difference but when I found out I could make something to pump air into it to raise the pressure into the 20s I thought I would attempt to make a device like this. If I could find the Gaxco I have I will give it another shot. I misplaced it and have to find it.

 

[WilsonPlayer101]

Guys, if any of you have an Instant Pot I think this would pressurize and restore the tennis balls within an hour. I could cook stew in an hour in this so I think an Instant Pot will do wonders for your balls.

Just kidding. If you wanted melted balls you should use this!

I have heard people who used a pressure cooker to do so though. A conventional pressure cooker, not Instant Pot. They installed a bike valve. Sealed it with

balls in it and pumped away and it worked. Just don't apply heat then the balls are toast so to speak.

 

[antony]

Reason is I had one but I was never successful with it restoring the bounce in the balls using that. I tried and it didn't work for me then a few years later same thing. In theory it should work seeing it makes the pressure in the device 14 PSI which should pump pressure into the balls. It works for you and other people but I never noticed a difference but when I found out I could make something to pump air into it to raise the pressure into the 20s I thought I would attempt to make a device like this. If I could find the Gaxco I have I will give it another shot. I misplaced it and have to find it.

Oh, I don’t really try to restore the pressure. I just try not to lose any after hitting. Thanks for explaining

 

[Injured Again]

Has there been a factory change with Penn balls? Opponents would sometimes bring Penn ATP Tour and the balls were great -- probably better than Wilson US Open. Think the name was then changed to Penn Marathon.

The Penn Championship are probably close to their bottom tier ball - they are the ones sold at Costco for around $2 a can. I think there's only a 50/50 chance of getting three balls in one can that bounce similarly, and they all go flat after about an hour or serious hitting.

The ATP Tour and Marathon balls are very nice, with good consistency and quality control.

 

[Holdfast44ID]

I'm using two beer/soda kegs and an air compressor for this. Works great!

 

[WilsonPlayer101]

I tried the pressurizer again and it was even better. The first time I had the balls in there for 3 days @ 28 PSI but this time I put the same balls in for 7 days @ 30 PSI and wow the bounce was even better. The felt was still good but you can see it will wear down more if we use it one more time. So we can do another pressure treatment again and the balls should be okay BUT we will use new tennis balls next week we play. We plan on using one can three times. The initial use then two times pressurized. My friend will bring a new can next time and he has the Penn Champion balls. I use those too just because the price is under $3 after tax. I know, not the best tennis balls. When it is my turn again I will buy Wilson US Open to see how well it works with the pressurizer and how long the felt will last. Will we go three uses or four or five? We shall see.

I am impressed by the pressurizer. If I needed to do more tennis balls than just 3 or 4 I would probably do the garden pesticide sprayer or painter pot. But then again maybe make one more water filter housing if I just needed 3 or 4 more balls pumped up.

 

[WilsonPlayer101]

A few random thoughts. The felt on premium balls tends to last a **lot** longer than on lower tier balls. When I practice with my son, we are basically going non-stop for the entire 90 minutes, and start another rally within a couple of seconds of when the previous one finishes. We both hit hard, with a lot of spin, and both of us use shaped strings. We will typically use two cans and even so, the felt on lower tier balls won't last two sessions or three hours. Two cans of the US Open balls are still playable after three sessions, though by that they start to lose their pressurization throughout a session and also start playing noticeably slower, like that the rubber has work hardened and is absorbing more energy from being hit or when bouncing on the ground.

Second thing is that here in the Pacific Northwest, a majority of our courts are indoors and they're pretty fast as well. Those of us who are tournament players and want to compete in places like southern California on slow outdoor courts, using repressurized balls works well because as they slow down but still retain their bounce, it's a good substitute for practicing on slower courts that we don't have.

Lastly, I purchased a PressureTube about 18 months ago. It's great for maintaining pressure but doesn't work well to repressurize balls because it can't survive the higher pressures to allow that to happen in a short timeframe. About 20 PSI is all it can take. Mines sprung a leak from two places right at the one year mark and I emailed the manufacturer to ask some questions, and got nothing in response. There was a leak in the plastic encapsulating the base of the schraeder valve, and another one at the bottom opening where the plastic is heat sealed.

Make one like mine. It holds pressure and I pump it up to about 35 PSI. I hear about too many problems with the PressureTube leaking.

 

[Injured Again]

Make one like mine. It holds pressure and I pump it up to about 35 PSI. I hear about too many problems with the PressureTube leaking.

I purchased a pre-assembled corny keg pressurizer over a year ago. Works great!

I'm in the process of trying to fix my leaky PressureTube so I can use it at low pressure (15 PSI) to help maintain the bounce of the green dot balls that I use when I hit with my wife.

 

[WilsonPlayer101]

I purchased a pre-assembled corny keg pressurizer over a year ago. Works great!

I'm in the process of trying to fix my leaky PressureTube so I can use it at low pressure (15 PSI) to help maintain the bounce of the green dot balls that I use when I hit with my wife.

I'm impressed by the Keg Pressurizers. If I used a lot of balls at one time I would use the Keg. I leave the balls in the pressurizers I make for two weeks. I have two now so I have enough for using pressurized balls every week pumped for two weeks. The balls bounce pretty good.

What is the cause of the leak in your PressureTube? Did you try to submerge it in water to see where the air is leaking out?

 

[louis netman]

There are DIY guides all over the internet. Make sure your seals are good

http://tt.tennis-warehouse.com/index.php?threads/large-tennis-ball-pressurizer.657879/

I go through a lot of balls and had two working corny kegs that pressurized the balls quite well -- The problem was getting them in.....and then getting them out.
Just a BIG PITA and waste of time, and that was only 120 balls. I need to swap out lots of 250+.

I have since sold the corny kegs to a brewer...

 

[WilsonPlayer101]

I usually just pressurize for a few days but decided maybe 2 weeks at 34 would be better and man were the tennis balls lively. This thing really does the trick. I recommend this to you to make one.

 

[Injured Again]

What is the cause of the leak in your PressureTube? Did you try to submerge it in water to see where the air is leaking out?

It primarily leaks around the Schraeder valve. The plastic surrounding the base of the valve isn't airtight any more. I tried heating up the plastic to shrink it, and then apply a bead of hot glue. Neither worked.

I believe the layers have also separated at the open end where the clip goes, and there's a minor leak there as well.

 

[WilsonPlayer101]

If you don't want to make your own look at what Head makes. Looks like it has a valve so it isn't one of those old yellow Tourna ones with no valve to pump it up -

https://headpressurizers.com/en/headx3pump/

 

[kayak4water]

That photo was cut off when I try to put the URL from Photobucket. I don't see at this forum to upload directly but you have to host it somewhere and then put the link in your post. I will try again.

This looks like one only needs to add a valve and a pressure gauge to the filter housing after drilling the holes.
Can one buy all parts from a big box home improvement store?

It’s tempting to try the ABS pipe project despite the difficulties you had with leakage. Maybe ABS doesn’t have the same air/water tightness in screw fittings as in cemented fittings?

I’m interested because something like this would make a nice gift for my friends who don’t use pressureless balls

 

[WilsonPlayer101]

I'm out and about now and can't type a thorough response now but will later this evening when I'm home. I will give better instructions on how to make one. This really extends the life and usage of the balls.

 

[WilsonPlayer101]

When I made mine I got some things at HD and some online.

The water filter housing I got at HD. Online I got the pressure gauge and the air valve. Not sure if you can get these at HD. You need that metal piece that screws into the water filter housing then screw the valve in it for it to fit.
You need not drill holes, the holes are there and are made to fit water pipes in it.

You also need white threading pipe tape to seal the connections to make it air tight.

I now have two. I have two because I found that if you pump it to about 34 PSI and leave it in for two weeks it makes the balls like new. I play once a week so say I open a new ball can and use the balls for a set or two. Put it in the pressurizer and leave it for two weeks. The next week open a new can then place in the second pressurizer. The next week take out the balls from the first pressurizer. Then the cycle repeats. If you play multiple times per week either make more than two or maybe get a garden sprayer and use that because they can hold more. I believe those get up to 60 PSI and you can hook up a pressure gauge. The hand held ones don't have a big enough opening for balls but the type that is a backpack style can fit tennis balls thru the opening.

If you have balls with not much felt left then pumping them up won't work BUT if the felt is fuzzy and healthy this works like a charm. I can get about four uses out of the balls. First time is using them new then three more after you pump them up.

 

[WilsonPlayer101]

As far as PVC pipe goes it's a good concept but I tried to make one and I could not get it to be airtight no matter what I did. Someone posted here he made a PVC pressurizer and it worked but one day it exploded. The end cap or something blew up and the explosion made a big boom and scared the heck out of his wife and neighbors. If you can get one to work then you can pump up more balls than the water filter one BUT it is hard to make it air tight and also maybe the end cap may blow off and you will have a big boom and a tennis ball cannon.

By the way, the water filter one you must not forget to push the red button to depressurize it becore opening it. I never forgot to but I can imagine if you don't you can be seriously hurt.