Upgrading a Tennis Ball Saver

happyandbob

Semi-Pro
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.
 

happyandbob

Semi-Pro
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.
 

struggle

Legend
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

Rookie
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.
 

happyandbob

Semi-Pro
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. (n)

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)_/¯
 
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happyandbob

Semi-Pro
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

Professional
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.
 

happyandbob

Semi-Pro
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

Hall of Fame
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.
 

happyandbob

Semi-Pro
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

Hall of Fame
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

G.O.A.T.
definitely seems like it. I checked this morning and it had dropped to 10 psi. (n)

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:

 

happyandbob

Semi-Pro
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:

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

Semi-Pro
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

Semi-Pro
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

Semi-Pro
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

G.O.A.T.
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

Semi-Pro
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

G.O.A.T.
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

Semi-Pro
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.
 
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