WaterWar.net

I was just thinking about modding my Explorer AP to CPS to improve shot time my goals are

Range 42 (+3' more)
Shot time 3 seconds on largest (x3 longer)

any thoughts about how many balloons to use in the conversion ?

If shot time is your main goal, you could just expand the chamber with some PVC pipe. Cut off the end, shove some pipe at it with some glue, attach an endcap, and done. You will have to open it and get the right size of pipe as you see fit. Increasing the size of the chamber will increase the shot time and gives you more air pressure volume as well.

If you are going for balloons, you are going to need a lot. Somewhere between 20-40, you may have to experiment a bit.
*Edit* I was definitely thinking of a K-mod here. A pure balloon PC would need somewhere between 20 and possibly over 100 balloons. 20 balloons would probably not provide enough oomph compared to other CPS, but I think it might be enough to power small nozzles.

I'd think even 40 is on the low side, some k-mods reach that. JLSpacemarine's CAR needed 75 to reach 50ft, but that's with a ball valve, a very straight flow path, a laminator and a generous pipe diameter. Balloon PC's seem to have caused issues for a few people on these forums, probably because there isn't a more rigid central bladder to build on as per a k-mod. Extending the current PC would definitely be easier, but a conversion to elastic is certainly doable and has it's own benefits. Definitely worth a shot, and you can always keep the original PC and extend that if it doesn't work as well as planned.

Simply sticking bare balloons is unlikely to work for a PC. There's a way to do it properly, but I'm not quite sure how. The problem is that the first few balloons are not shaped right. The result is that later balloons go on very unevenly, and the whole PC breaks sooner. LRT may work though.

I would avoid soakinader's suggestion: PVC is way heavier and you can't truly bond it chemically to the rest of the plastic. Better to just replace the whole PC (or as most of it as you can) instead, if you're going for air pressure.

Just take an old spherical cps bladder, and use it as a base for more balloons.

I don't know about water guns but, I have used PVC pipe to extend the pressure chamber of a Nerf Titan, and I have seen several people use it on other high-pressure nerf guns (Big Blasts, bazookas, etc).
As for the mythical balloon PC, has anyone tried starting with the first balloon filled with a little bit of water/sand (not enough to make it expand)? I would imagine you would have to use dozens of balloons, and you would have to use several different sizes.
*Edit* How large is the opening where the PC goes into the reservoir? Maybe you could insert a Hydrocannon PC! XD

DX is being kind and giving me a CPS 1-3-5 PC for this so my stats need some updating

Range 42'
Shot time 10 seconds Largest (3x)
Shots per tank 2
Pumps to full, 41

Is this theoretical or have you accomplished this yet?

I am waiting for the PC to do this with

I found a hose clamp today, and put the 2500 PC from Ben's failed HC 2500 into it. PC capacity is 30oz, I need to find some selector parts I misplaced before re mounting the selector and range testing it but overall I'm very pleased with the result.

Whoa 30 oz/ 900mL? Aren't you worried about the PC overexpanding here?
Would love to see a video. How big is the ID of the aperture? How much output can you get out of it I wonder?

I increased the 2500 PC capacity before trying the mod. It really doesn't need to stretch that much more to get to 30 oz. I wouldn't worry about it rupturing. Of course, this isn't exactly a common mod, so I could be wrong.

Water Warriors blasters internals are about 10x without the selector, so even without a nozzle I still get 3x the shot time I would be getting on the stock largest setting.

I Finally mounted the selector on my Explorer K and I must say shot time on it is impressive, It's much better than a stock Explorer (M4 gave it to me cause he didn't like it stock). It's like a mini vindicator all I need now is to nozzle drill with 5X and 10x.

Haha, I have to say, that is pretty cool. Weird how there isn't a normal Explorer, only ultimate.
But in any case, sure it might be like a mini Vindicator but it's got some serious CPS power behind it! Way more power and PC capacity than a vindicator. Can't wait to see a video, maybe?

Wow, that is amazing. I would love to see some pics and or video. What did you use to make the nozzle selector?

outside it looks stock, I wish I could get a video but I don't have a camera

Very cool. How many shots/tank do you get? I drilled one nozzle on my explorer and it was a good riot blast. Also, how many pumps does it take to hit full power?

Not even a camera phone? These days, not having a digital camera of some kind is like not having television... or internet. O.0

it's a CPS so full power can be reached in 3 to 4 pumps, I give it around 30 pumps at first and the shot time in around 7 seconds on stock largest. It gets 3 full shots per tank.