DIY Tennis Ball Re-Pressurizing System
NOTE: I offer this information free of charge and with no warranty and I accept no responsibly to any injury or damages you might cause to yourself, to others or property. If you want a professional grade product backed by a company with customer serve then I suggest going with reBounces.
To re-pressurize Tennis balls I use four Ball Lock style Cornelius Soda kegs. Each keg can hold upwards of 60 balls totaling 240 balls which fills my ball cart.
This system uses CO2 at 50-60PSI to re-pressurize tennis balls. Supposedly, pressuring with air does work, but it takes upwards of 4-6 weeks to re-pressurize balls. While CO2 only takes a days or two to a week depending on the type and quality balls.
The downside to using soda kegs is that the opening, while large enough for a ball to pass through, is not large enough for balls to just poor out. It requires taking some out by hand and shaking the kegs to get balls out. Once you have the technique down it only takes a few of minutes to remove ball from a keg.
Re-pressurizing of yellow balls lasts 7 to 14 days +/- and takes 3-7 days to re-pressure depending on the quality of the ball, etc.
I get approximately 20 Kegs filled at 50PSI with 5lbs of CO2. Your mileage may vary due to temperatures. My local cost for having a 5lb CO2 tank filled is $16.75 (with tax) A larger tank will cost more but might be a better value for having refills done as it tends to be cheaper with bulk.
That's approx $0.80 cents per keg. I use four kegs at a time so I can re-pressure 240 balls for slightly over $3.00. Less than the cost of a single three ball can of tournament balls. (Someone correct me if my math is off.)
Kegs safety: as I only go as high as 50-50PSI. I am well within the 130PSI working pressure of the kegs. There is also an over pressure release value on the keg lid to prevent over pressuring.
There are three main components to the DIY Tennis Ball Re-Pressurizing System:
1) Cornelius Soda Keg(s)
2) CO2 Tank
3) CO2 Regulator and hose
Preparing the keg(s)
Each keg has two posts on top. One is the “liquid post” and the other is the “gas post”. Within the keg are two metal tubes. The long “dip tube” which attaches under the “liquid post” and the short “gas tube” under the “gas post.” The long “dip tube” could restrict the number of ball a keg is able to hold. You can either replace the “dip tube” with another “gas tube” or cut the long tube down by unscrewing the “liquid post” to remove it. Be careful when removing the “liquid post” as inside is a “Poppet Valve Assembly”with a spring can can easily become lost.
CO2 Tank
The CO2 tank I have used is a 5LBS aluminum cylinder tank. Steal is cheaper, but heavier and not as rust resistant. When buying a tank make sure it has been recently tested and certified. From what I understand The Department of Transportation (DOT) requires that most portable CO2 tanks, both new and used, be re-certified every five years.
CO2 Regulator
A CO2 Regulator controls amount of CO2 that flows from the tank/cylinder in the keg. Do not attempt to use CO2 in a keg without a regulator. You can get regulators that control gas from one tank with one or two gauges. One gauge reads the pressure reached in the keg and the other indicates the amount of CO2 left in the tank. Single gauge regulators lack the gauge to read the tank level. Regulators have a pressure adjustment knob or screw that allows you to set the amount of CO2 delivered to the keg.
Putting it Together
Putting it all together is quite simple. Connect the hose to the CO2 regulator's outlet fitting use a small hose clamp and secure tightly. Attach the ball lock fitting onto one of the soda keg Posts. Yes. That is it.
Set the regulator to 50PSI and turn the value on. You will hear some rumblings inside the keg for a few moments. When the regulator has reach the set PSI inside the keg you can disconnect the ball lock fitting.
Rough costs are:
$115 for two used kegs, shipped. You can also order a 4 pack.
https://www.cornykeg.com/…/converted-ball-lock-cornelius-s…/
$68.88 for a 5lb CO2 tank.
https://www.amazon.com/…/B00…/ref=oh_aui_detailpage_o09_s00…
$54.83 for a CO2 regulator (sends the correct amount of gas to the kegs.)
https://www.amazon.com/…/B00…/ref=oh_aui_detailpage_o09_s01…
$11.90 for hose and ball lock tap connector that connects from the regulator to the keg.
Link for the hose and ball lock:
https://www.amazon.com/…/B00…/ref=oh_aui_detailpage_o01_s00…
50 cents for a small hose clamp to go on the hose that connects art the regulator.