How To Pressurize / Revive Old Tennis Balls...

[rjw]

Clairharmony...whatever you're on, you need to share....

[Boxer]

Originally Posted by ClairHarmony

I have corny keg as well, it already came pre-fitteed for tennis ball recharging. It was I believe $60 or so on clearance from a fly-by-night tennis ball cannister charging company around 11 years ago. I did not know what the rebadged pressurized cannisters they were selling were called...but now I know! Learn something new everyday, corny kegs!

Glad to help with the identification

BUUUT, the one to me FATAL problem with this execution was that the opening on the corny kegs used was obviously NOT designed with tennis bobo ball use in mind.

Yep -- as I mentioned in post #47 above...bit fiddly. Not, IMHO as bad as you make out though -- I upend the keg in one arm and put my other hand in the opening and use it to "deliver" the balls as you put it. I can more or less pour them into the pratice bucket in a matter of seconds...fast as upending a 5 gallon paint bucket full of balls?? No, but not fatally tedious.

This said, I eventually soon found the thing pointless after that first case of balls. The tennis ball savers from Unique sports, bought three of them to hold a total of 9 balls. They work not quite as well, as for sure the balls don't feel good as new each time you play; but they're close enough to be more than useable...no need to ferment them in the trash can just yet.

Doing that is a lot more expensive if you need enough balls to fill a decent size practice hopper or worse yet a ball machine. It probably comes down to what your usage model is...if a smaller number of balls is good, the keg is probably overkill and more trouble than its worth, I agree.

Regarding pressure delivery, I should perhaps state that I had a light duty compressor to hand (air power tools) before I started on the tennis ball science experiment. That takes all the "work" out of it for sure

Beyond this board, no one really cares enough about these to mass produce and special order them...

No further qualification required, I'd say...this is clearly into mad scientist territory in my book and although I get good results I got at least as much fun out of treating it like a science fair project with my kids as anything else -- cheapish engineering and physics lesson with a dash of entertainment and I get a "green" attaboy for recylcing as well

[zorcy3]

Originally Posted by PrinceMoron

OK so what I want is a way to pressurise a ball so much that when I serve it just explodes. Must be a way.

Don't say I didn't warn you, but yes. There is a way and it can still go off in your hand. You will loose lots of balls trying to get just the right pressure, too. You will need a tank that will go high enough to charge the balls with enough pressure to explode. Yes the stainless steal tanks. Stay with all new ball, same make, model and production run. Over charge them. Start at say 50 PSI for a week. When you open the tank, if one does not explode right away, put it back in. Charge to 60PSI. Do this ever 10 PSI till the first one pops, explodes or pfisses out. Then take your balls out, in a black ball bag to increase the pressure in the sun. Gently set them next to you, and pull them out one at a time. Serve.

The idea is that they are right at the limit of bursting, the hot sun will increase it further. The sudden impact will burst them..... Ever hold a balloon in your hand and it hurt when it popped? 100 times that, so it will hurt. Damage to your racket, use an old one that needs restrung.


Good luck, and you were warned.....

[zorcy3]

Originally Posted by zorcy3

Beyond this board, no one really cares enough about these to mass produce and special order them...

Not so, I DO make them. And I do sell them.

The main draw back, is that once you have the 1 or 2 you need, you don't buy anymore. They are stainless steal, they don't break, they don't need much for repairs and you can use it as a jack stand for your car. It's not like the electronics industry, you have to keep updating. I find they only sell for so long, then the business dies down. Was thinking about doing ****, open up the field. Once the pros in one area are done, most of your customers are done too.

Maybe I need a time release that will deteriorate the tank after 2 years. Like MS Windows does.

[Ronaldo]

Originally Posted by ClairHarmony

I have corny keg as well, it already came pre-fitteed for tennis ball recharging. It was I believe $60 or so on clearance from a fly-by-night tennis ball cannister charging company around 11 years ago. I did not know what the rebadged pressurized cannisters they were selling were called...but now I know! Learn something new everyday, corny kegs!

BUUUT, the one to me FATAL problem with this execution was that the opening on the corny kegs used was obviously NOT designed with tennis bobo ball use in mind. Great for getting drunk, but not so much tennis. It's too small I tell you! Meanning in other words, you can't POUR your balls in and out of the thing...only one measely ball at a time, maybe two if I'm generously stretching my memory a bit.

Does the thing work? Absolutely. I never had to overcharge the balls. I just left them at 15-17 PSI which was fine as I would oepn a new batch of Grand Priz balls and leave them in there. Basically, just take out 9 to play each time, then dump them when the felt was gone. Polayed like new the whole time.

This said, I eventually soon found the thing pointless after that first case of balls. The tennis ball savers from Unique sports, bought three of them to hold a total of 9 balls. They work not quite as well, as for sure the balls don't feel good as new each time you play; but they're close enough to be more than useable...no need to ferment them in the trash can just yet. Same deal, use until felt is no good. Honestly, the mini tennis ball maintainers (they should be called this, as they certainly are not ball revivers as the corny kegs can be) are FAR more convenient, take up zilch space but in your bag, don't require a mini air compressor (sound like a bleeting pig for crying out loud, even the crickets in the cupboard, ceiling tiles, and my hair, shudder and complain!!! ...wheww, glad that's over), or high-quality, high-volume, bicycle pump...not cheap, btw. 'Bout 60 bucks. With a cheap K-Mart special pump...your arms will be tiring from the boring and monotnous pump, plus you'll be hunching over much lately? With the nice pump, it felt like it took a good 1 miniute 44 seconds or so while watching the boob tube in high-figh CRT to pump her up...then it was all over. I did not find the experience terribly satisfying, but it was better than the bleeting mini air compressor which took about 45 seconds of excruciating Casey Gag-Anthony!

By comparison, it was an acceptable happy-medium solution to me, with the added benefit of getting in some nice tennis elbow therapy as well...and hey, that's boring as well. Double your pleasure, I guess.

Really, two big problems to me. For these to be justfiable, A) you need to be able to hold 150 balls or so in a SINGLE container, and B) be able to POUR the balls in and out.

I can't overstate the importance of B) especially, enough! To me, it's pretty freakin' important. The pump you up aspect honestly ain't all that bad, and like I said probably good for the ol' elbow as well; but I can't tell you how frustrating it is to buy something like this for hopper use mainly, and find that it's a no go. It's excruciatingly slowwww....to have to plop out one cute, adorable, baby puppy ball at a time! I mean I love delivering babies y'all in my other life as a baby deliverer...but this is too much time and hassle folks to be practical!

With pressureless balls, yeah they stink like oversized golf ball nut sacks, but you can just take the dump them and forget them approach. Incidientally, I drove cross-country during the heat of summer with the corny keg, and it depressurized in the trunk like by half within three days....

I believe the company said they were working on bringing a new and improved larger opening to market, but then they either went under from lack of interest, or simply stopped caring. The market for these is decidedly small pond...the only thing is, on TW you are liable to think this is a large spacious blue lagoon with a loving and committed, agless Brook Shields who just called me...no really, it's true.

Beyond this board, no one really cares enough about these to mass produce and special order them with an *appropriately* sized opening to be useful for high-volume, DAILY use...as would be required by a serious amateur hobbyist, greedy pig, private tennis club owner...mua-ha-ha! Or, your friendly local neighborhood teaching pro/prviate eye and bounty hunter, named Skip McCallister at your service, I also do window cleaning.

Honestly, I only really see that big green machine thingy or the tennis ball charger 150 being "worth" it in the long haul.

I honestly don't think the corny keg is worth the trouble long haul, UNLESS you can get one with a large enough opening to pour balls. In that case, having to use two or even three of these wouldn't be all that half-bad. Corny kegs are robust like tanks, they look like giant, oversized fire extinguishers that sit in a corner. Picking them up and down and looking like you can hurl it out the window, makes you look and feel like an incredibly strong and masculine He-man in front of your woman. The feeling is just incredible! But that's where the endorsement ends for me.

The tennis ball charger 150 has been around forever, in hindsight I think they got the right balance of attibutes. Niche market, so charge up the wazoo if you hope to stay in business. The people who REALLY gonna need, are gonna buy, and beech and complain all the way to picking up the phone; but yeah, in the end, they probably gonna still buy...muttering, bunch of nice smelling, freaking, paper money for a bunch of no good, stinky, smelly overrated hunk of plastic with a lid, valve stem, and boiling needle point, pressure gauge in it#@%#!!!!!

But then? Yeah, you'll probably in the end be satisfied with it, and not complain no more after the first week. Then, you'll begin to compliment yourself in front of the mirror and flex for no good reason. The tennis ball charger has a built-in pump, can be poured, and holds the holy sweet spot of balls...150 or so, and it's *good to go*.

ClairHarmony, I own two Pro-Bounce canisters to pressurize balls! Chose not to buy the ball washer as my balls are clean.

http://web.archive.org/web/200211271...ro-bounce.com/

[zorcy3]

Wow, I just got a letter from reBounce asking me information about my tank. Did anyone else get it? They must be afraid I will infringe on their idea.

[leroy_sunset]

Thread revival!

A while back, there was a TT thread that had pics of a repressurization chamber for tennis balls using a corny keg. I wanted to try this, as I have a basket of very decent (but flat) Penn balls that I would like to use for serve practice.

First, I got a $30 used corny keg from craig's list of goodness. It's a Pepsi-style keg, and I got a tap and gas fitting for the keg from my local homebrew supply store ($9 each). The keg holds roughly 60 balls.

Next, I got a length of 1/4" ID plastic tube that's reinforced for pressure ($2) and two hose clamps ($3! for tiny hose clamps?) from my local hardware store.

Last, I got a Schrader valve (bike tube valve, basically) with threads from an auto supply store for $2.

I heated the tubing up on one end with a hair dryer to make it soft, and then inserted the Schrader valve, then clamped.

I pressurized the keg to 30psi. I heard some thumps inside the chamber - either popped balls or collapsed balls. We'll see in a week or so what's up.

One last thing - eye protection! Pressure vessels + DIY = explosion risk.

[Torres]

http://www.tennis.com/gear/2012/10/g...bounces/39899/

Price is insane for normal folk, but a potential purchase for a club or group of coaches coaching beginners/improvers (less felt wear).

[leroy_sunset]

OK, I gave it a week. I checked the balls after 3 days at 30psi to see if any popped, but they were all fine. I pumped the keg back to 25psi for the remainder of the week.

Of 60 balls, 9 weren't giving me the bounce I wanted to see. 1 of those 9 was totally dead.

I would also say 3 of the balls were "over-inflated."

I am giving the 9 sub-par balls another week in a keg at 27psi. I will serve with the 51 graduates tomorrow night.

[goran_ace]

Originally Posted by leroy_sunset

OK, I gave it a week. I checked the balls after 3 days at 30psi to see if any popped, but they were all fine. I pumped the keg back to 25psi for the remainder of the week.

Of 60 balls, 9 weren't giving me the bounce I wanted to see. 1 of those 9 was totally dead.

I would also say 3 of the balls were "over-inflated."

I am giving the 9 sub-par balls another week in a keg at 27psi. I will serve with the 51 graduates tomorrow night.

Btw, I love your Rebel With A Cause poster.

[leroy_sunset]

Originally Posted by goran_ace

Btw, I love your Rebel With A Cause poster.

Thanks, I've had it since high school. Turns out it's a pretty rare poster. I thought about trying to get JMac to sign it last year at an event I attended, but I was too lazy to elbow my way through a sea of children and pro autograph hunters.

[jrxl]

Originally Posted by leroy_sunset

OK, I gave it a week. I checked the balls after 3 days at 30psi to see if any popped, but they were all fine. I pumped the keg back to 25psi for the remainder of the week.

Of 60 balls, 9 weren't giving me the bounce I wanted to see. 1 of those 9 was totally dead.

I would also say 3 of the balls were "over-inflated."

I am giving the 9 sub-par balls another week in a keg at 27psi. I will serve with the 51 graduates tomorrow night.

Did you have any noticeable pressure loss over the week in the keg?

[beernutz]

I built a similar system using 3 corny kegs about a year ago and keep about 150 balls pressurized in them for use in my ball machine (a Silent Partner Star). I already had the kegs and tubing from my old homebrewing days as well as a nice car tire pressurizer so I think I spent less than $10 in additional parts to complete the system. The only downside I've found is that it takes a bit of time getting the balls into and out of the kegs between uses.

What I do is try is use the balls during a three day period, for example I unload them on a Friday and then leave them unpressurized until after using them the next Sunday when I put them back under pressure. This cuts down on the time spent just moving balls into and out of kegs. I timed it once and it takes about 1.5 seconds per ball grabbing them three at a time, and since a keg typically holds about 65 balls it takes a little under two minutes per keg to load or unload or about 5 minutes total for all the balls I want to use, which is really not that big of a deal.

To jrxl, I'm not leroy obviously but I don't see much pressure loss even over an extended period of time in the keg. I don't use as much pressure as leroy does (mine was determined through trial and error) so his results may be different. I did spend a good bit of time getting the kegs to seal properly by replacing old gaskets and using a keg lube/sealer product on them.

[dak95_00]

I've got that poster and another which lists his match record from ......I think.....1984. I was a big McEnroe fan back in the day. At least, I think I have them around here somewhere.

[leroy_sunset]

No measurable pressure loss whatsoever.

By the way, these were flat balls. If it's just pressure maintenance, then 15psi is fine. But I needed to "recharge" these balls, so I went with a higher pressure. Seems to have worked.

[txt858]

With a few modifications, couldn't this be a viable alternative?



Tank Capacity: 4 Gallons
Operating PSI: 44 - 58 PSI

http://www.harborfreight.com/lawn-ga...yer-65040.html

[retrograde]

Originally Posted by txt858

With a few modifications, couldn't this be a viable alternative?

If you read the customer feedback, there are comments about the pressure chamber being very small, so the sprayer needs to be constantly re-pumped. Not sure if this would affect ability to pressurize balls? I also wonder how long it would hold pressure, Harbor Freight doesn't always have the highest quality products (sure are cheap though).

[retrograde]

Originally Posted by leroy_sunset

Thread revival!

A while back, there was a TT thread that had pics of a repressurization chamber for tennis balls using a corny keg. I wanted to try this, as I have a basket of very decent (but flat) Penn balls that I would like to use for serve practice....

Just wanted to give a shout out for the excellent photos and description. I followed your lead and am now fermenting my first batch of balls

I got a used 5-gal Cornelius keg from Beverage Elements with ball locks on the gas-input and liquid-output fittings (those shiny round "posts" on top of the keg). Also bought the necessary plastic quick-disconnect for the gas fitting.

The gas fitting internally has a spring-loaded pressure valve (a "poppet") that lets air into the keg from your air pump. Normally both the gas and liquid fittings are shut tight when there isn't a disconnect attached.

Most ball lock kegs have a manual pressure relief valve on top of the lid and this comes in handy when it's time to pull the balls out. Pin lock kegs usually don't come with that kind of lid, although they can be retrofitted easily and are sometimes sold that way.

I used the same air tank schrader valve shown in leroy_sunset's photo. Instead of using the high pressure hose (usually rated to 200+ psi) I used regular vinyl hose that's good up to 50 psi). The tip to heat the 1/4" ID hose before inserting the schrader valve is a good one since its a very tight fit. The hose clamps are stainless steel, 5/16" wide, 7/32" to 5/8" OD.

After pumping air into the keg, I attached a tire pressure gauge to the schrader valve to check the pressure, then removed the disconnect and its hose (the poppet seals the gas fitting).

I'm pressurizing at 28 psi right now (150 strokes with a bicycle floor pump). Like others, I also heard a few "popcorn popping" sounds from inside the keg when pressure went over about 25 psi.

[leroy_sunset]

Hey all, I just wanted to give an update about my repressurization. After about a month at 25psi, I sorted through all the balls and tossed the ones that weren't giving me the bounce I wanted. About 10% were duds (these are all regular Penns). I then pumped the keg back to 25psi and left it for about a month. I took my wife out for some practice last week and about 1/2 of the balls were "overinflated" such that they actually bounced a bit more lively than even out of a brand new can. These old balls (some are well over 1 year old) hit almost like new. I am very pleased. I will be storing them at 15psi from here on out.

[IdrinkYourMilkshake]

Originally Posted by leroy_sunset

Hey all, I just wanted to give an update about my repressurization. After about a month at 25psi, I sorted through all the balls and tossed the ones that weren't giving me the bounce I wanted. About 10% were duds (these are all regular Penns). I then pumped the keg back to 25psi and left it for about a month. I took my wife out for some practice last week and about 1/2 of the balls were "overinflated" such that they actually bounced a bit more lively than even out of a brand new can. These old balls (some are well over 1 year old) hit almost like new. I am very pleased. I will be storing them at 15psi from here on out.

I have two kegs with my ball machine. I never had any luck with Penn balls. But US Opens are awesome and work great.