Upgrading a Tennis Ball Saver

[happyandbob]

I have a big box of dead tennis balls that I've been collecting to eventually ship out to https://www.recycleballs.org. I was looking at the balls the other day as I was dropping a new set in, and many of the balls are dead but the felt seems to be in decent shape.

I have a couple of the yellow tennis ball savers that I use now and then (they work meh) and thought I might be able to repressurize them if I can add more pressure to those yellow savers.

I bought a tire valve stem to install on it to see if it would hold more pressure ($9 for pack of 4)

grabbed some dead balls. this one is fuzzy but I wanted to make sure the ball was pretty dead.

drilled a 1/2" hole in the top of the saver

installed the valve

pumped it up to just under 30 psi

it bowed out the sides, top, and bottom -- it doesn't sit flat on the bottom anymore

The whole thing took 5 minutes. So far, I don't hear any audible leaking. I'll report back on how the balls look in a week.

 

[JEDI MASTER]

i did that too last year.. unless you have new o-ring seals... mine slowly leaked.. 2 days later..back to 0 pressure.

 

[happyandbob]

I happen to have just replaced the o-rings a month ago. maybe I'll have better luck, but probably not I'm guessing. Either way, I'm not liking how the whole thing deformed. I'm going to see what I can do to buttress the sides.

 

[JEDI MASTER]

I happen to have just replaced the o-rings a month ago. maybe I'll have better luck, but probably not I'm guessing. Either way, I'm not liking how the whole thing deformed. I'm going to see what I can do to buttress the sides.

they can only withstand around 10-15lbs of pressure...

 

[struggle]

Yeah, 30 is way too much for these.

I thought they were supposed to create around 16 or so on there own compression but can't recall.

Keeping the o-ring lubed is crucial.

 

[BenC]

I did the same thing but drilled the white side since the material seems thicker there. I think the best strategy is to use the valve to maintain pressure (around 15 psi) since some of it escapes and some goes into the tennis ball itself. Too much pressure might damage the container and/or cause the balls to collapse.

 

[Crazy Finn]

Small Pony Keg works better than your ball saver for re-pressurizing.

 

[happyandbob]

Yeah, 30 is way too much for these.

I thought they were supposed to create around 16 or so on there own compression but can't recall.

Keeping the o-ring lubed is crucial.

definitely seems like it. I checked this morning and it had dropped to 10 psi.

now that I started, I guess I'll turn it into a little project. maybe I'll glue some schedule 40 pvc and a screw cap to the top of the inner sleeve. I was hoping there would be some engineering tolerance and when the thing is marketed to deliver 14 psi that the vessel would be designed to withstand at least 25 psi. it was worth a shot ¯\_(ツ)_/¯

 

[happyandbob]

Small Pony Keg works better than your ball saver for re-pressurizing.

thanks for the tip I am sure it does, but it seems a bit big for my needs I suspect.

 

[Nate7-5]

Pressureball.com

Been using them for over a year and they are fantastic.

 

[happyandbob]

Pressureball.com

Been using them for over a year and they are fantastic.

thanks! I considered but saw that several folks had issues with the seal busting after a couple of months. How much pressure do those things hold? enough to revive a dead ball or only enough to keep fresh balls lively?

 

[GeoffHYL]

thanks! I considered but saw that several folks had issues with the seal busting after a couple of months. How much pressure do those things hold? enough to revive a dead ball or only enough to keep fresh balls lively?

I have 2 pressureball devices. I fill them to 20 PSI, have left them at that pressure for months at a time, no problems. I think going above that could cause issues with the plastic material. 20 PSI is a bit high anyway, the balls end up too bouncy if left in there for too long.

 

[Nate7-5]

I use them to keep balls at slightly above 15psi so I can use them for 5-6 sessions over 3 weeks

 

[happyandbob]

I use them to keep balls at slightly above 15psi so I can use them for 5-6 sessions over 3 weeks

gotcha. I'm going to keep tinkering to see if I can make something small that will help me revive some completely dead balls I have. will definitely look at pressureballs to replace the yellow saver that I just killed

 

[Injured Again]

gotcha. I'm going to keep tinkering to see if I can make something small that will help me revive some completely dead balls I have. will definitely look at pressureballs to replace the yellow saver that I just killed

If you want to revive dead balls, you're going to need more pressure than a Pressuretube can support. I had a Pressuretube that lasted 53 weeks (one week past the warranty period!). In all my time, it never worked as any more than a pressure maintainer. Now that I have a corny keg that I pump up to 32 PSI, flat balls can regain most of their bounce within two weeks.

Yeah, the corny keg is way larger than I need. I intend on filling most of it with tennis balls that I never intend to play with again, just to reduce the internal volume and to reduce the number of pumps needed from my mountain bike floor pump.

 

[Crazy Finn]

My buddy has one of these, it's pretty great. 1.75L mini-keg.

Homebrew Beer Kegs

Why bother bottling your homebrew when you can keg it? Pick up some corny kegs and kick those bottles to the curb. Never again will you find yourself bottling beer for hours on end. If you already have a homebrew keg system, be sure to pick up some extra o-rings and poppet valves so you're not...

www.northernbrewer.com

 

[happyandbob]

If you want to revive dead balls, you're going to need more pressure than a Pressuretube can support. I had a Pressuretube that lasted 53 weeks (one week past the warranty period!). In all my time, it never worked as any more than a pressure maintainer. Now that I have a corny keg that I pump up to 32 PSI, flat balls can regain most of their bounce within two weeks.

thanks. I figured the pressure balls would just be something that helps maintain pressure

I have parts on order for two different variations on capping a new tennis ball tube with pvc fittings to see if I can get that to hold 25-30 psi. Will report back.

if that doesn’t work I’ll probably try to make a complete pvc ball tube but will be heavy to carry in my bag I suspect

 

[Injured Again]

thanks. I figured the pressure balls would just be something that helps maintain pressure

I have parts on order for two different variations on capping a new tennis ball tube with pvc fittings to see if I can get that to hold 25-30 psi. Will report back.

if that doesn’t work I’ll probably try to make a complete pvc ball tube but will be heavy to carry in my bag I suspect

I've seen plans for a PVC tube ball pressurizer in this forum. I guess it take a high pressure capable PVC pipe and extra sturdy endcaps and fittings for anything that holds more than nine or ten balls. I think the problem with those is how to get a reliable seal. The threaded end couplers rely on the glue for a watertight (and presuably airtight) seal. The caps that screw on all leak.

Good luck and would love to see what you put together.

 

[travlerajm]

definitely seems like it. I checked this morning and it had dropped to 10 psi.

now that I started, I guess I'll turn it into a little project. maybe I'll glue some schedule 40 pvc and a screw cap to the top of the inner sleeve. I was hoping there would be some engineering tolerance and when the thing is marketed to deliver 14 psi that the vessel would be designed to withstand at least 25 psi. it was worth a shot ¯\_(ツ)_/¯

It sounds like your seal might be leaking, but also, some of the pressure drop is due to air being pushed into the balls. Venting frequently improved performance in mine:

https://tt.tennis-warehouse.com/index.php?threads/supercharged-3-ball-tennis-ball-pressurizer.670729/

 

[happyandbob]

It sounds like your seal might be leaking, but also, some of the pressure drop is due to air being pushed into the balls. Venting frequently improved performance in mine:

https://tt.tennis-warehouse.com/index.php?threads/supercharged-3-ball-tennis-ball-pressurizer.670729/

That's good info. Thanks! And maybe you're right that the pressure is getting into the balls. They do seem to be firmer now that it's been a couple of days.

I'm continuing to experiment with increasing the ability to hold PSI. I took out the seal and filled that groove with vaseline to prevent any air from escaping from that side of the o-ring as well. Next I'm going to tightly wind the outer shell with thread and then cover it with JB weld, making a little composite sleeve to provide additional support right where the oring sits on the yellow can when closed.

 

[happyandbob]

update. I think the vaseline behind the o-ring eliminated whatever leak there might have been. I pumped it up to 28 yesterday and it was still in the mid-25s this am (presumably some of it went into the ball).

To see if there was any leak, I pumped it to 30 and then put it in a bathtub of water to see if I could see any bubbles. No bubbles! Pics below, one with flash and one without. I had to hold it down because it wanted to float.

I may hold off on the JB weld to see how this holds up over time, but promising so far.

 

[happyandbob]

I've seen plans for a PVC tube ball pressurizer in this forum. I guess it take a high pressure capable PVC pipe and extra sturdy endcaps and fittings for anything that holds more than nine or ten balls. I think the problem with those is how to get a reliable seal. The threaded end couplers rely on the glue for a watertight (and presuably airtight) seal. The caps that screw on all leak.

Good luck and would love to see what you put together.

Ok, so the parts came in today. This one looks the most promising:

I was hoping to slip an opened ball sleeve through the top of this and have the metal flange catch on the lip just below the threads. Then I would use this and teflon tape to seal the threads

It's so close but the metal flange on the ball sleeve just barely catches on the lip, but not enough to provide a real mechanical connection. I was thinking JB weld around the metal flange to secure it to the PVC and then fill in the gap below the flange and the PVC with non-exanding foam insulation or liquid nails.

If only that flange was 1 or 2 mm wider in diameter it would work perfectly. Rats. Need to think about what the best way to build out that flange just a tiny bit would be. Maybe I'll try to leverage that plastic cap that comes on the can.

If anyone has any suggestions, I'm all ears.

 

[happyandbob]

Ok, here is an update. I had assumed there was a single manufacturer for all of these tennis cans, and maybe there is, but for whatever reason, Wilson cans seem to be shaped slightly differently than Penn cans. The metal lip on this Wilson can, caught on the collar of the PVC better than Penn cans did.

Using JB Weld, I spread a liberal layer of epoxy just under the metal ring of the can and slid it up through the PVC adapter, then pulled it back down until the metal ring sat on the collar.

Once that cures, I'm going to epoxy this gasket I made from the plastic cap of the tennis ball can to the top of the metal ring and then epoxy over that to create the air seal.

 

[travlerajm]

Ok, here is an update. I had assumed there was a single manufacturer for all of these tennis cans, and maybe there is, but for whatever reason, Wilson cans seem to be shaped slightly differently than Penn cans. The metal lip on this Wilson can, caught on the collar of the PVC better than Penn cans did.

Using JB Weld, I spread a liberal layer of epoxy just under the metal ring of the can and slid it up through the PVC adapter, then pulled it back down until the metal ring sat on the collar.

Once that cures, I'm going to epoxy this gasket I made from the plastic cap of the tennis ball can to the top of the metal ring and then epoxy over that to create the air seal.

That looks like a really cool project! I’m not sure if the material in the lid will adhere well to the epoxy. If the lid is a polypropylene like plastic, then you need a special glue for it that is more chemically compatible. Hardware stores like Home Depot carry polypropylene glue.

 

[happyandbob]

That looks like a really cool project! I’m not sure if the material in the lid will adhere well to the epoxy. If the lid is a polypropylene like plastic, then you need a special glue for it that is more chemically compatible. Hardware stores like Home Depot carry polypropylene glue.

It is, unfortunately. I'm hoping that the epoxy won't necessarily have to stick to it, just give it some physical support (like fibers in a concrete). My plan is to spread a layer of JB weld over the metal ring, then the plastic ring, then another layer of JB weld -- totally encapsulating the plastic. Not sure it's going to work, but my hope is that if the ring is totally encapsulated, the JB weld won't have to stick to it, just stick to itself, the metal, and the PVC. The ring inside, I'm hoping just provides support against air pressure/leaks. Fingers crossed.

 

[travlerajm]

It is, unfortunately. I'm hoping that the epoxy won't necessarily have to stick to it, just give it some physical support (like fibers in a concrete). My plan is to spread a layer of JB weld over the metal ring, then the plastic ring, then another layer of JB weld -- totally encapsulating the plastic. Not sure it's going to work, but my hope is that if the ring is totally encapsulated, the JB weld won't have to stick to it, just stick to itself, the metal, and the PVC. The ring inside, I'm hoping just provides support against air pressure/leaks. Fingers crossed.

You might consider trying rubber bands sealed with rubber cement, or a large silicone o-ring sealed with silicone.

 

[happyandbob]

You might consider trying rubber bands sealed with rubber cement, or a large silicone o-ring sealed with silicone.

Thanks. That's my plan to seal the screw top. I'm encapsulating that gasket with JB weld to give some strength to the seal between the metal ring and the PVC. Under that seal, to fill between the clear can and the PVC pipe I bought some runny silicone (the kind used to find leaks and seal car windshields). So I'll fill that void with silicone. Then where the screw top meets the JB weld, I'm going to put a bead of silicone caulk or silicone glue or Sugru so there is flex there.

 

[happyandbob]

These savers are working pretty well for me. I had one start leaking but that stopped as soon as I resealed the groove for the o-ring with vaseline. At some point I will probably move to something more viscous -- thread locker or molding clay maybe? But all four of these are holding 25+ psi consistently.

 

[travlerajm]

These savers are working pretty well for me. I had one start leaking but that stopped as soon as I resealed the groove for the o-ring with vaseline. At some point I will probably move to something more viscous -- thread locker or molding clay maybe? But all four of these are holding 25+ psi consistently.

You could mass produce those and retire.

 

[happyandbob]

Using vaseline to fill that channel where the o-ring sits was a good proof of concept, but I'm noticing that I need to touch up the vaseline every 5-10x I open and repressurize the cans. With an eye toward more durability, I thought I'd take two of the cans, clean them very well and fill that channel with non-hardening modeling clay instead of vaseline.

I worked the clay into a thin rope and filled the o-ring channel with the clay, making sure it was pressed in very well to fill any voids.

Then I pressed the o-ring into the clay, cutting away any extra that o-ring pushed out.

My youngest happened to have two different brands of modeling clay handy, so thought I might as well try out two different kinds to see if one works better than the other.

I put a thin bead of vaseline on the o-ring like the manufacturer recommends and resealed it back up. It holds 30+ psi like a champ.

 

[happyandbob]

Update. The clay seems to do a better job than the vaseline holding pressure in the mid to high 20s, but if you pump it up to 35, here is what the clay looks like after a week at 35.

It still held pressure, but the clay was a mess and got forced out of the groove.

This seems to be working ok and I suspect will be much lower maintenance. I'm kicking myself for not trying this first. I put a rubber band behind the o-ring to act like a shim and have the o-ring make a tighter seal against the walls of the saver. It's a lot harder to screw down, but seems to be holding pressure just fine at 30 psi.

 

[TennisPete]

Hi guys,

New to the forum, I've been looking at ball repressurization for a while and been trying to come up with a decent solution and came across this thread. Thought I'd chime in.

I'm currently using a Hozelock 7 litre garden sprayer (Part number Hozelock 4231) - it's the only sprayer I could find from the different manufacturers with a wide enough mouth for tennis balls, enough capacity for 12 balls, with good enough build quality so it doesn't leak.

It's got a 3 bar (45 psi) pressure release valve and cost me £25. It holds easily 12 balls at a time and the balls don't get in the way of the pump mechanism.

75 pumps takes it up to 45 psi, (3 bar, the stage at which the safety release valve pops) so extrapolating from that 53 pumps takes it up to 32psi (which seems to be the consensus level for bringing very old balls back to life). 25 pumps takes it up to 15psi (which is roughly can pressure, for keeping new balls alive between matches).

I've deliberately not put a proper pressure gauge on it, so I'm trusting the accuracy of the release valve. I really wanted to find the cheapest and easiest solution, and as soon as you start adding gauges, schrader valves, etc., you end up spending more money than you save on balls!

I also looked at the different PVC pipe home-build options, but from previous experience in pool pipe maintenance I decided it probably wasn't worth the effort and the cost. Corney Kegs seem nice, but too expensive and too much hassle for me.

My solution is working well so far, I'm planning to do some tests on it and maybe a YouTube video to share the knowledge, but at the moment I can't really see a cheaper and easier solution. Going down the garden sprayer route meant I didn't need to make any modifications at all. The YouTube video wouldn't be very interesting - all you do is buy the tank, put the balls in and pump it up 25 times! I just need to find the solvent which gives the new ball smell to introduce to the tank for maximum satisfaction!

Hope this is useful.

 

[travlerajm]

Hi guys,

New to the forum, I've been looking at ball repressurization for a while and been trying to come up with a decent solution and came across this thread. Thought I'd chime in.

I'm currently using a Hozelock 7 litre garden sprayer (Part number Hozelock 4231) - it's the only sprayer I could find from the different manufacturers with a wide enough mouth for tennis balls, enough capacity for 12 balls, with good enough build quality so it doesn't leak.

It's got a 3 bar (45 psi) pressure release valve and cost me £25. It holds easily 12 balls at a time and the balls don't get in the way of the pump mechanism.

75 pumps takes it up to 45 psi, (3 bar, the stage at which the safety release valve pops) so extrapolating from that 53 pumps takes it up to 32psi (which seems to be the consensus level for bringing very old balls back to life). 25 pumps takes it up to 15psi (which is roughly can pressure, for keeping new balls alive between matches).

I've deliberately not put a proper pressure gauge on it, so I'm trusting the accuracy of the release valve. I really wanted to find the cheapest and easiest solution, and as soon as you start adding gauges, schrader valves, etc., you end up spending more money than you save on balls!

I also looked at the different PVC pipe home-build options, but from previous experience in pool pipe maintenance I decided it probably wasn't worth the effort and the cost. Corney Kegs seem nice, but too expensive and too much hassle for me.

My solution is working well so far, I'm planning to do some tests on it and maybe a YouTube video to share the knowledge, but at the moment I can't really see a cheaper and easier solution. Going down the garden sprayer route meant I didn't need to make any modifications at all. The YouTube video wouldn't be very interesting - all you do is buy the tank, put the balls in and pump it up 25 times! I just need to find the solvent which gives the new ball smell to introduce to the tank for maximum satisfaction!

Hope this is useful.

I’m tempted to try this when I ever get back home.

 

[happyandbob]

following up, here is the best way to do this -- credit to a buddy of mine who came up with this clear config:

Using the clear saver allows you to monitor if the balls are collapsing or not. This is critical for restoring dead balls, pressure won't get into the ball once the ball collapses. With the yellow savers, you have to guess or try to hear the collapse.

Buy a rubber sheet and cut out to match the inner diameter of the outer tube (the cap), this goes into the bottom of that tube. Then when you screw down the inner tube, it compresses that rubber gasket, making the seal. The pressure value goes into the inner tube, not the outer tube. You end up using the whole contraption upside down, but it easily holds 35 psi and you can see the state of the balls the whole time.

I'm still using the yellow tubes for storing balls in use (with a thin rubber band behind the o-ring), and while those will hold 30+ psi, I usually have those pumped to 20 psi so balls stay fresh.

 

[travlerajm]

following up, here is the best way to do this -- credit to a buddy of mine who came up with this clear config:

Using the clear saver allows you to monitor if the balls are collapsing or not. This is critical for restoring dead balls, pressure won't get into the ball once the ball collapses. With the yellow savers, you have to guess or try to hear the collapse.

Buy a rubber sheet and cut out to match the inner diameter of the outer tube (the cap), this goes into the bottom of that tube. Then when you screw down the inner tube, it compresses that rubber gasket, making the seal. The pressure value goes into the inner tube, not the outer tube. You end up using the whole contraption upside down, but it easily holds 35 psi and you can see the state of the balls the whole time.

I'm still using the yellow tubes for storing balls in use (with a thin rubber band behind the o-ring), and while those will hold 30+ psi, I usually have those pumped to 20 psi so balls stay fresh.

Nicely done!

 

[Booger]

Do you think there's a better way to do this with PVC pipe and fittings? This way you skip the weak plastic and o-ring?

 

[happyandbob]

Do you think there's a better way to do this with PVC pipe and fittings? This way you skip the weak plastic and o-ring?

I messed around with a couple of PVC based configurations. The low pressure PVC is too weak to hold any significant pressure and the schedule 40 PVC is hella heavy. Plus schedule 40 PVC is meant to be glued for pressure applications, any threaded PVC connections or caps do not hold pressure. It was a big fail, at least for me. Maybe someone can come up with something better than I tried.