Super Soaker Central forums

rflach5 · 06-19-2006, 06:15 PM

Hello, my name is John, I am new to the forum. I am facinated by the guns you have all put together. It looks like a rewarding hobby. I have been lurking for a few days and am interested in the Air Pressure homemade that Doom posted. One thing keeps bugging me: The water that is in the backpack must get replaced with air as it is used, right? So how does the air get into the backpack tank? Is there a valve for that? Any insight from you experts out there for a newbie?

Regards,
John F.

Silence · 06-19-2006, 07:16 PM

Welcome to SSCentral, rflach3!

In a recent thread, another new user asked why there was a backpack in one of the pictures in the APH article, and you might or might not have seen that. In any case, the article is a bit vague about that; and while you might have caught the fact that the backpack is the reservoir, the details might not have been mentioned. The backpack is identical to that used in the trashbag version of the Backpack Mod, which basically involves "clamping" a trashbag filled with water between two threaded fittings. One of the fittings has an attached barb, and a hose connects the barb to the APH. This method is quite strong, incredibly flexible, cheap, and allows for the volume to decrease as the water is used.

However, you certainly are correct--if you use a solid reservoir in the backpack, then air displacement might be a problem. This could be solved by a check valve in the cap to the reservoir (further increasing the price); but make sure the intake is separated from the check valve in such a way that only water is sucked into the pump, as opposed to air.

It would be an interesting method to put the check valve directly in the backpack, possibly decreasing the weight and the size of the main soaker body. However, if you use a free-spinning barb fitting (as I have obtained), then the pressure probably wouldn't be held properly on the instroke. In fact, the tube might not even hold the pressure itself! That's a shame, but it isn't too big a problem...

rflach5 · 06-19-2006, 10:24 PM

Thanks for the info. Interesting idea, using a deflatable bladder. My idea for my gun involved putting 2 - 1 liter soda bottles on the gun as a resovoir. I realize this adds tremendous weight to the gun and also gives me basically one shot since the gun holds 1.5 liters of water and I am providing 2 liters, but the goal of my gun is not for it to be portable. I want a 1 shot super soaker surprise attack gun. Every year my nephews nail me with water guns. I want to pull this bad boy out and say in a cheesy australian accent: "That's not a gun, this is a gun!". I already have a solution for the interconnect between the soda bottles and the PVC, but it dawned on me that I will need to let air into the soda bottles if I want to take water out. Herein lies my dilemma. Maybe I will scrap the bottle idea and mount some sort of bladder instead? Maybe a couple of hot water bottles or some sort of trash bag bladders inside PVC tubes.

Silence · 06-20-2006, 09:16 AM

Sounds like you'll have quite a bit of fun!

Well, if you're keen on an onboard reservoir (possibly more impressive than a backpack one), you could do the trashbag in PVC idea. However, people (pepper, Duxburian, etc.) have certainly done standard PVC ideas; in fact, to my knowledge, Duxburian prefers to do so. He's probably more informative when it comes to such reservoirs...

My impression is that, if the reservoir is significantly larger than the pressure chamber, then the "negative pressure" (pressure below one atmosphere) that makes the outpump harder won't build up as much until the end. If you open the reservoir's cap every now and then, you really shouldn't have a problem. Also, you could try a simple PR gun, but that won't come recommended by me.

Maybe you could use one of SS's or BBT's reservoir caps (the ones that have the holes in them) that contain tiny check valves and fit it onto PVC threads. You can get quick fill caps from a form at the Super Soaker website, and they might have the check valves themselves--a drastic but effective solution. You'd probably have to use a ton of Teflon tape, though...

DX · 06-20-2006, 11:39 AM

You could use PVC directly for a reservoir. 2"-3" works best, length depending on the overall size of your gun and the design.

Here's an example:

Longer and wider is better than taller, since you want the weight of the water evenly distributed across your homemade. Also note the screw-off cap on the top of the reservoir. That is a very good way of filling the reservoir, and you don't have to worry about negative pressure. When screwed somewhat loose, negative pressure won't form. You could also use a T and a check valve instead, but that costs more and is IMO not really necessary.

Silence · 06-20-2006, 12:11 PM

@ Duxburian: Will the reservoir leak if the gun is held upside-down with the cap somewhat loose? I'm assuming it won't be terrible, and I wouldn't be shaking the gun anyway, but it's good to know...

DX · 06-20-2006, 12:14 PM

Well, it depends on how "somewhat loose" the cap is. I screw it on tight enough that no water comes out when you shake the gun upside down. Enough air gets through the threads even when that tight.

rflach5 · 06-20-2006, 05:20 PM

Wow. I like the PVC tank with the screw on cap, but I like even better just adapting to a check valve.......Hmmmm. Well the gun goes together tonight so I better make up my mind!

DX · 06-20-2006, 06:04 PM

You will need a large check valve if you want fast fill rates. Big check valves are expensive, but do their job better than a cap. The cap, while kinda imperfect, is pretty darn cheap. So it actually is a hard choice.

rflach5 · 06-20-2006, 10:19 PM

Well, it is done! I went with the 2 liter bottle on top of the compression tubes. I fitted the bottle with a check valve my neighbor had lying around. Here are the pics:
http://mywebpages.comcast.net/johnflach/100_4366.JPG
http://mywebpages.comcast.net/johnflach/100_4367.JPG
http://mywebpages.comcast.net/johnflach/100_4368.JPG
http://mywebpages.comcast.net/johnflach/100_4369.JPG

I will test it tomorrow when the glue has dried on the check valve.

wetmonkey442 · 06-21-2006, 01:45 PM

Very impressive! I have to say that is one of the better looking APHs out there. It does look like it would be slightly top heavy, but that's the price you pay. Stream pics, plus range stats are always appreciated. Nice job!

Give it a paint job, and that thing'll look pretty intimidating.

joannaardway · 06-21-2006, 03:00 PM

My only negative comment is the postion of the water intake on the reservior.

With regards to backpacks, a large reason for converting my CPS 3200 backpack to hose fittings is so I can fit it to any soaker I modify with a hose fitting.

Thus my new Copper SPCgH has a CPS 3200 backpack.

rflach5 · 06-21-2006, 05:39 PM

So I'm in Subway today and I notice behind the counter a shelf with al the soda bottles on it for the fountain. What peaked my interest was the bottles appeared to be in cardboard boxes. So I asked the manager if they ship the bottles back for refill when they are empty, and she said "no, they are not bottles they are bags inside of the box"!!!!!!! WOW did that get my interest. So I asked her if they refill the bags and she said "No, we throw them away"!!!!!!!
I immediately asked her for an empty one and she handed over a nice, tough plastic bag with a neck on it and the cap that goes over the end of the neck for shipping! Score! There is a valve in the neck that prevents the liquid from escaping until they attach a hose, but I am confident I can defeat that and have me a free bag. To top it all off I told her what the bag was for and she said that if I need any more, please let her know. I will send more pics when I convert my gun over to backpack tonight!

rflach5 · 06-21-2006, 05:45 PM

I will post range and stats as soon as possible. I am leaving friday for my "mission" at the campgrounds, so war statistics will follow too.

Silence · 06-21-2006, 06:12 PM

Wow--that's just like a homemade I was thinking of doing today! I have mentioned that I've obtained most of the PVC needed for my soaker, and I'm thinking about putting a reservoir on top--though it will be made out of PVC. Congratulations on your first homemade!

wetmonkey442 is right--that does look very impressive. However, I'm not sure if you used primer--I believe it does help, and although there are some who don't use it (and I'm not going to argue about whether to use it or not), I wouldn't build a homemade without it.

06-19-2006, 06:15 PM	#1
rflach5 Junior member Join Date: Jun 2006 Posts: 12 UserID: 730	Hellow, new to Forum Hello, my name is John, I am new to the forum. I am facinated by the guns you have all put together. It looks like a rewarding hobby. I have been lurking for a few days and am interested in the Air Pressure homemade that Doom posted. One thing keeps bugging me: The water that is in the backpack must get replaced with air as it is used, right? So how does the air get into the backpack tank? Is there a valve for that? Any insight from you experts out there for a newbie? Regards, John F.

06-19-2006, 07:16 PM	#2
Silence Administrator Join Date: Apr 2006 Location: Virginia Posts: 3,244 UserID: 576	Welcome to SSCentral, rflach3! In a recent thread, another new user asked why there was a backpack in one of the pictures in the APH article, and you might or might not have seen that. In any case, the article is a bit vague about that; and while you might have caught the fact that the backpack is the reservoir, the details might not have been mentioned. The backpack is identical to that used in the trashbag version of the Backpack Mod, which basically involves "clamping" a trashbag filled with water between two threaded fittings. One of the fittings has an attached barb, and a hose connects the barb to the APH. This method is quite strong, incredibly flexible, cheap, and allows for the volume to decrease as the water is used. However, you certainly are correct--if you use a solid reservoir in the backpack, then air displacement might be a problem. This could be solved by a check valve in the cap to the reservoir (further increasing the price); but make sure the intake is separated from the check valve in such a way that only water is sucked into the pump, as opposed to air. It would be an interesting method to put the check valve directly in the backpack, possibly decreasing the weight and the size of the main soaker body. However, if you use a free-spinning barb fitting (as I have obtained), then the pressure probably wouldn't be held properly on the instroke. In fact, the tube might not even hold the pressure itself! That's a shame, but it isn't too big a problem... __________________ Forum Rules

06-19-2006, 10:24 PM	#3
rflach5 Junior member Join Date: Jun 2006 Posts: 12 UserID: 730	Hello, New to Forum Thanks for the info. Interesting idea, using a deflatable bladder. My idea for my gun involved putting 2 - 1 liter soda bottles on the gun as a resovoir. I realize this adds tremendous weight to the gun and also gives me basically one shot since the gun holds 1.5 liters of water and I am providing 2 liters, but the goal of my gun is not for it to be portable. I want a 1 shot super soaker surprise attack gun. Every year my nephews nail me with water guns. I want to pull this bad boy out and say in a cheesy australian accent: "That's not a gun, this is a gun!". I already have a solution for the interconnect between the soda bottles and the PVC, but it dawned on me that I will need to let air into the soda bottles if I want to take water out. Herein lies my dilemma. Maybe I will scrap the bottle idea and mount some sort of bladder instead? Maybe a couple of hot water bottles or some sort of trash bag bladders inside PVC tubes.

06-20-2006, 09:16 AM	#4
Silence Administrator Join Date: Apr 2006 Location: Virginia Posts: 3,244 UserID: 576	Sounds like you'll have quite a bit of fun! Well, if you're keen on an onboard reservoir (possibly more impressive than a backpack one), you could do the trashbag in PVC idea. However, people (pepper, Duxburian, etc.) have certainly done standard PVC ideas; in fact, to my knowledge, Duxburian prefers to do so. He's probably more informative when it comes to such reservoirs... My impression is that, if the reservoir is significantly larger than the pressure chamber, then the "negative pressure" (pressure below one atmosphere) that makes the outpump harder won't build up as much until the end. If you open the reservoir's cap every now and then, you really shouldn't have a problem. Also, you could try a simple PR gun, but that won't come recommended by me. Maybe you could use one of SS's or BBT's reservoir caps (the ones that have the holes in them) that contain tiny check valves and fit it onto PVC threads. You can get quick fill caps from a form at the Super Soaker website, and they might have the check valves themselves--a drastic but effective solution. You'd probably have to use a ton of Teflon tape, though... __________________ Forum Rules

06-20-2006, 11:39 AM	#5
DX Wicked Super Admin Join Date: Feb 2004 Location: Easton / New London, CT Posts: 1,574 UserID: 75	You could use PVC directly for a reservoir. 2"-3" works best, length depending on the overall size of your gun and the design. Here's an example: Longer and wider is better than taller, since you want the weight of the water evenly distributed across your homemade. Also note the screw-off cap on the top of the reservoir. That is a very good way of filling the reservoir, and you don't have to worry about negative pressure. When screwed somewhat loose, negative pressure won't form. You could also use a T and a check valve instead, but that costs more and is IMO not really necessary. __________________ Mess With the Best, Get Soaked Like the Rest!! 2004 Red Sox - World Series Champions 2007 RED SOX - WORLD SERIES CHAMPIONS! 2003 Patriots - Super Bowl Champions 2004 Patriots - Super Bowl Champions 2007 Patriots - God Damnit!

06-20-2006, 12:11 PM	#6
Silence Administrator Join Date: Apr 2006 Location: Virginia Posts: 3,244 UserID: 576	@ Duxburian: Will the reservoir leak if the gun is held upside-down with the cap somewhat loose? I'm assuming it won't be terrible, and I wouldn't be shaking the gun anyway, but it's good to know... __________________ Forum Rules

06-20-2006, 12:14 PM	#7
DX Wicked Super Admin Join Date: Feb 2004 Location: Easton / New London, CT Posts: 1,574 UserID: 75	Well, it depends on how "somewhat loose" the cap is. I screw it on tight enough that no water comes out when you shake the gun upside down. Enough air gets through the threads even when that tight. __________________ Mess With the Best, Get Soaked Like the Rest!! 2004 Red Sox - World Series Champions 2007 RED SOX - WORLD SERIES CHAMPIONS! 2003 Patriots - Super Bowl Champions 2004 Patriots - Super Bowl Champions 2007 Patriots - God Damnit!

06-20-2006, 05:20 PM	#8
rflach5 Junior member Join Date: Jun 2006 Posts: 12 UserID: 730	Wow. I like the PVC tank with the screw on cap, but I like even better just adapting to a check valve.......Hmmmm. Well the gun goes together tonight so I better make up my mind!

06-20-2006, 06:04 PM	#9
DX Wicked Super Admin Join Date: Feb 2004 Location: Easton / New London, CT Posts: 1,574 UserID: 75	You will need a large check valve if you want fast fill rates. Big check valves are expensive, but do their job better than a cap. The cap, while kinda imperfect, is pretty darn cheap. So it actually is a hard choice. __________________ Mess With the Best, Get Soaked Like the Rest!! 2004 Red Sox - World Series Champions 2007 RED SOX - WORLD SERIES CHAMPIONS! 2003 Patriots - Super Bowl Champions 2004 Patriots - Super Bowl Champions 2007 Patriots - God Damnit!

06-20-2006, 10:19 PM	#10
rflach5 Junior member Join Date: Jun 2006 Posts: 12 UserID: 730	Well, it is done! I went with the 2 liter bottle on top of the compression tubes. I fitted the bottle with a check valve my neighbor had lying around. Here are the pics: http://mywebpages.comcast.net/johnflach/100_4366.JPG http://mywebpages.comcast.net/johnflach/100_4367.JPG http://mywebpages.comcast.net/johnflach/100_4368.JPG http://mywebpages.comcast.net/johnflach/100_4369.JPG I will test it tomorrow when the glue has dried on the check valve. Last edited by Ben : 06-21-2006 at 02:18 PM. Reason: Images too large for forum, turned into links. ;)

06-21-2006, 01:45 PM	#11
wetmonkey442 Super Moderator Join Date: Jun 2003 Posts: 256 UserID: 47	Very impressive! I have to say that is one of the better looking APHs out there. It does look like it would be slightly top heavy, but that's the price you pay. Stream pics, plus range stats are always appreciated. Nice job! Give it a paint job, and that thing'll look pretty intimidating.

06-21-2006, 03:00 PM	#12
joannaardway Do not adjust your TV set Join Date: Feb 2006 Location: SW Hertfordshire, England Posts: 875 UserID: 549	My only negative comment is the postion of the water intake on the reservior. With regards to backpacks, a large reason for converting my CPS 3200 backpack to hose fittings is so I can fit it to any soaker I modify with a hose fitting. Thus my new Copper SPCgH has a CPS 3200 backpack. __________________ "Over the hills and far away, she prays he will return one day. As sure as the rivers reach the seas, back in his arms again she'll be." - Over the Hills and far away, Gary Moore "So many people have come and gone, their faces fade as the years go by. Yet I still recall as I wander on, as clear as the sun in the summer sky" - More than a feeling, Boston

06-21-2006, 05:39 PM	#13
rflach5 Junior member Join Date: Jun 2006 Posts: 12 UserID: 730	A free backpack bag! So I'm in Subway today and I notice behind the counter a shelf with al the soda bottles on it for the fountain. What peaked my interest was the bottles appeared to be in cardboard boxes. So I asked the manager if they ship the bottles back for refill when they are empty, and she said "no, they are not bottles they are bags inside of the box"!!!!!!! WOW did that get my interest. So I asked her if they refill the bags and she said "No, we throw them away"!!!!!!! I immediately asked her for an empty one and she handed over a nice, tough plastic bag with a neck on it and the cap that goes over the end of the neck for shipping! Score! There is a valve in the neck that prevents the liquid from escaping until they attach a hose, but I am confident I can defeat that and have me a free bag. To top it all off I told her what the bag was for and she said that if I need any more, please let her know. I will send more pics when I convert my gun over to backpack tonight!

06-21-2006, 05:45 PM	#14
rflach5 Junior member Join Date: Jun 2006 Posts: 12 UserID: 730	I will post range and stats as soon as possible. I am leaving friday for my "mission" at the campgrounds, so war statistics will follow too.

06-21-2006, 06:12 PM	#15
Silence Administrator Join Date: Apr 2006 Location: Virginia Posts: 3,244 UserID: 576	Wow--that's just like a homemade I was thinking of doing today! I have mentioned that I've obtained most of the PVC needed for my soaker, and I'm thinking about putting a reservoir on top--though it will be made out of PVC. Congratulations on your first homemade! wetmonkey442 is right--that does look very impressive. However, I'm not sure if you used primer--I believe it does help, and although there are some who don't use it (and I'm not going to argue about whether to use it or not), I wouldn't build a homemade without it. __________________ Forum Rules

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)