Super Soaker Central

I am planning on building a APH (according to this plan) and I had a question about the pipe sizes. Why do the plans use 1/2 inch pieces for the lower half of the water gun, but 3/4 inch pieces for the final half? Why not build the entire water gun out of 1/2 inch pieces?

Because the 1/2" pipe restricts the flow to the nozzle if you used it there. and 1/2" is the ideal size for the pump

You can use whatever size pipe you want. I choose 3/4" pipe for the upper half because I could get a nice 3/4" blast without the nozzle on and 1/2" for the lower half because larger makes the pump harder as Specter said. If you're strong, you might like 3/4" for the entire water gun. If you want to consolidate some pieces and save some money, you can use 1/2" for the entire water gun.

If you're building a CPH, you may wish to stick to 1/2. I would avoid using 3/4" for the entire gun since that creates a ton of dead space, and makes it more difficult to empty the gun when you're done using it. Plus, if you're strong with pumping, that strength can go into building greater pressures instead of faster pressurizing. It depends.

3/4" is only really necessary for riot blasts and larger nozzles. In CPH's, the barb will be the main restricting factor, so 3/4" generally isn't necessary and you can still get good results out of 1/2". 1/2" is also a more appealing option if you're building a trigger system for the firing valve.

As Ben said, it's your choice. Most parts to homemades are optional and no homemade guides have to be strictly followed, they're just a good place to start at and to follow if you're not sure what you're doing or what's going on.

Other changes that can be made from the APH guide would be to include more threaded parts for easier disassembly, or fewer threaded parts for more strength. Also, for the pump, I'd recommend duct tape for the spacer instead of electrical tape. However, spacers aren't really even necessary as long as the groove is able to hold the O-ring in place. If you want more o-rings, 2 would be the maximum needed.

Teflon tape usually isn't actually necessary, but strongly recommended for parts that hold pressure. For parts that are commonly exchanged (such as nozzles or hose barbs), I never use tape on them. Since the hose barb (that connects to the backpack) never has to hold any pressure, I never use tape on it, which makes it easier to exchange with different parts I may need.

Thanks for the help everyone, I think I'm going to make the entire water gun out of 1/2", since it will a little simpler.

Another question about the water reservoir: I'm not sure whether I'm going to build a backpack or on board, but here is my question. Does the reservoir need an air intake at the top? It seems that as water is pulled out of when the pump is extended that air needs to come in and fill the empty room. How do other people handle this problem?

For hardshell reservoirs (which is most resrvoirs), the simplest way is to drill a tiny hole (as small as possible) into the reservoir, usually the cap. However, this might leak, so another method would be to use a check valve to allow air inside. However, it is obviously a more expensive way, and takes up a bit more space. Stock water guns solve the problem by having a rubber pad over a hole in the cap. When water goes over it, it weighs down on the pad and it seals but still allows air to go in. Sometimes, this system breaks, causing annoying leaks in the cap.

For soft backpacks, there is usually no hole for them, they simply deflate as they're used. If you can find a camp shower (a big, 5 gallon sack, which shouldn't be filled up all the way when used in combat), it will be easiest to create a backpack with it. Backpacks are generally easier to construct than onboard reservoirs since such resevoirs need good volume and balance. However, some homemades have been very creative with solutions to avoid the problems of conventional designs. Here's an example of one. (though honestly, I can't figure out some of the parts myself) However, these kinds of practical designs seem to be mostly in the CPH configuration. Rearrangement at the least, is needed for similar air pressure designs.

A bit late here, but I'd recommend 1/2" too, as it'll keep the costs down, especially for the ball valve. Smaller ball valves are easier to turn, too. And finally, a 3/4" riot blast (no nozzle) has laughably poor range and is pretty useless.

A pinhole at the top of the reservoir is a good idea. A few drops of water might leak out if you're running around, but you won't notice it since there will probably be water everywhere from filling, getting hit, etc. Don't use a check valve.

For the record, the article on building backpacks is here.

Why shouldn't you use a check valve?

They're more expensive and take up too much space.

Also, I should add that a piece of fabric over a large inlet can let you pump quickly while also limiting leaks if water is sloshing around inside.

I still find that pinholes, unless very small (1mm or less, most drills only go down to 1/16"), still cause unacceptable amounts of leaking. When a super soaker's cap fails, it's even worse because the holes are large and causes enormous leaking, which can waste a ton of water and soak the user. The most reliable method is any kind of seal system, and the check valve works as that. If needed, smaller check valves for small brass fittings or tubing can be used instead of the regular kind that attaches to PVC.

With a soft reservoir of any kind, you don't even have to worry about pinholes nor check valves. However, if you need a hardshell reservoir and don't want to deal with regular check valves, you can improvise your own seal or even your own check valve. Or you could just go with a soft reservoir that's able to deflate as it's used up.

One example of an improvised seal is, say you need a typical female cap that threads on. Instead of a cap with a pinhole, you could use a female adapter and a plug. Drill a small hole in the plug (about the size of a 2x or 3x nozzle, which would be about 2-3mm), find some rubber material to seal it, put a spring behind it, then cram a washer into it. Easier said than done; the tricky part is finding everything to the correct size, but I believe it can be done.

C-A_99 wrote:I still find that pinholes, unless very small (1mm or less, most drills only go down to 1/16"), still cause unacceptable amounts of leaking.

Why not try making the pinhole with a PIN? Of course this might be difficult for thick plastic. If you're using a pin with a head, you could try hammering it.

Indeed a drill bit will be too large. The hole needs to be small enough that the water's surface tension inhibits it flowing though.

I might actually have to do that to one of my 12k's since the cap's seal is pretty screwed up. Perhaps I could glue the seal in first before resorting to this though, I'd have to have a good look at it.

Still, there's go to be a reason that water gun companies spend a little more to have caps with seals rather than just have small holes. Then again, those seals don't allow much air either if the cap itself is on tightly. The best method I'd say, would have to be the quick fill caps that the current SS uses. (such as on the FF)