It Is Here

[Hyperion330]

Should I put the cement on the joints of all the PVC, or over everything? Also, should I put the cement on before or after the assembly of the pieces?

[Ben]

I said to follow the instructions on the cans. This is what I did though:

First I put all the pieces roughly in the order they were in my gun. They were not put together. Then, I primed them. To do that I took the primer and put it on the ends of the PVC by wiping it around a few times. I also did the parts of the PVC joints that would be glued, basically the inside of the joint. I then waited about 4 hours to glue them, even though the can said something like 2.

To glue them I first isolated the parts that needed to be glued and those who didn't. I did not glue anything that will not be under any pressure at all, basically everything in the nozzles after the ball valve and everything before the first check valve. I am going to glue that later though, so maybe you should just glue it all. I also got out my plumbers tape, this stuff makes the screw on things much stronger. You just wrap that around the threaded part and get maybe 2 or 3 layers in, and then screw on the other end. I got it screwed on extra hard by putting one end in a clamp and twisting hard with some grip thing. To glue all the pieces I applied the glue to the ends of the PVC pieces and the insides of the joints they're being glued to. That's what the can said to do at least. It also said to twist as you push it in a bit, so I did. I believe that helps spread the PVC cement. I then glued everything together. However, on the PCs I used more PVC cement than normal because the endcap's and reducer's area is much larger. Just make sure everything that is going to be touching has some cement on it.

I think I'll add that to the article.

[wetmonkey442]

I did the way, that my dad said works best. I put the primer on and then with in 20 seconds I put the glue one. This made for a very stable connection.

[BlueSmudge]

yeah, I have years of experiance in plumbing, and I've used probably 5 different brand names of PVC glue, and all of them worked fine with putting the glue on right after the primar. The purple primar is basically a weak form of the glue that roughens up/softens the PVC so that the glue works better. And because it is like the glue, it too only takes 10 seconds to take effect.

Also, after you twist the PVC as you glue it, you need to push down hard on the pieces you are connecting because for the first 10 seconds the glue will try to push the pieces apart.

If you are making Doom's homemade, then you will need to make a backpack. Since Doom's backpack mod sucks private spot, you should make it out of piping. If you are not adding in a quick fill feature, that means that the backpack will never take more pressure than a few PSI of negative energy. That means that you Don't need a high pressure pipe. I would recommend ABS piping. It's the black stuff that is also in the plumbing section. It is cheaper, and lighter. Usually used for waste lines. The big upside is cheaper, since with a backpack you are working with 3" or 4" piping. If you plan on using this piping you have two choices for glue.

1.)ABS glue (duh!)
2.)Universal glue.

If you are using ABS glue, you will also need to buy PVC glue for the rest of the gun. You need to use Universal if there is any place on you homemade where ABS touches PVC. Also if you want to, you can use Universal glue in place of PVC glue. That way you only need one bottle. It works almost as well.

Sh*t that was long, heheh
good luck

[Hyperion330]

The "thing" in the materials list is called a reducing male adaptor, or an increasing female adaptor.

[Hyperion330]

My homemade is finished, and there are two problems:
1. Pump sprays back water (pump not airtight)
2. Tiny leak in pressure chamber (small enough for water to bubble through, but large enough for air to flow freely)

I know how to fix the leak, but how could I fix the pump?

[Ben]

You could fix the pump by making the electrical tape more tight. It takes some time, but eventually I got it right on Ol' Bessie. Remember to use vaseline on it too, it's thick so it will also help with the seal.

If you want to you could make a pump like pepper did, using a wooden dowel rod and an O ring. He said it didn't leak at all.

http://forums.sscentral.net/index.php?showtopic=36

Read that, the pictures are broken but they can be seen here.

[wetmonkey442]

Well, I couldn't find an aluminum rod, so I used a wodden dowel with electrical tape, but it either is too thick and gets stuck, or is too thin and isn't air tight. I just can't seem to get the right balance.

Also-I was thinking about using an o-ring, but I was afraid it would start slipping around on the wodden dowel when I try to pump. What would keep it on one place on the pump?

[Veteran]

One quick question, the handle and the pump seem to be spaced far apart. For people with smaller arms like me, would this be a problem? (I just bought the parts)

[wetmonkey442]

This is an important odea I just had when I was testing my gun again. tIf I build this again, it is important to know that you should try to make both the pressure chamber and the piping that is going to to be unde rpressure as small as possible. Believe me, I have a lot of piping, and it takes well over a hundred pumps to get this thign to even shoot out a minimal amount of water.

[Ben]

Also-I was thinking about using an o-ring, but I was afraid it would start slipping around on the wodden dowel when I try to pump. What would keep it on one place on the pump?

Pepper said there was no problem with it at all, so I don't think that it will move around. Just do what pepper said he did.

One quick question, the handle and the pump seem to be spaced far apart. For people with smaller arms like me, would this be a problem? (I just bought the parts)

I don't exactly get what you're saying, but since it's homemade if something is too long for you then you could always change it.

This is an important odea I just had when I was testing my gun again. tIf I build this again, it is important to know that you should try to make both the pressure chamber and the piping that is going to to be unde rpressure as small as possible. Believe me, I have a lot of piping, and it takes well over a hundred pumps to get this thign to even shoot out a minimal amount of water.

Yes! Even my 1.5 liter PC is a little too large. I think a single 4" ID 6" chamber would be the best size because my single 4" ID 4" chamber is a little too small for it's output (it's about 750 ml).

[wetmonkey442]

^^^ I have a great idea to soilve this problem. Okay, so I made another PC before I decided to use only one. The second PVC was put together, but never glues. What I could do, is cut the 3 inch tubing in the second PC shorter, to make the PC smaller (how short were the 3inch piping in your PCs, Doom?). I could then glue the PC together. I then take my gun as it is now. I could use a jigsaw and cut the PVC leading from the pressure chamber and to the pressure chamber shorter than it is now. Remove the old pressure chamber. Glue together the new PC. Attach the new PC to the shorter PVC piping on both sides. Not only will this reduce the amount of pumping I need to do, but it will also give me the chance to make better seals.

EDIT: spelling

[wetmonkey442]

Well, I di what I suggested, and I got much better results. It took about 35 pumps to fully presurize (this is with a cps 1500 pump), and the riot blast nozzle got about 25 feet of range. My 1/4" nozzle got 36 feet of range. These are good results, but why are they so low compared to other people's fidnings. I only have one tiny little leak at the top of the pressure tank, and it doesn't seemt o be affecting the range much.

[Ben]

how short were the 3inch piping in your PCs, Doom?

As I said in my article and posts, I used 4" legnths of 3" ID PVC for both of the PCs.

I think you should pump some more, get some more pressure. I think my double chamber version will perform like that at around 35 pumps, I use about 45-50 normally.

[wetmonkey442]

Originally posted by DoomSoaker@Jun 30 2004, 06:48 PM

As I said in my article and posts, I used 4" legnths of 3" ID PVC for both of the PCs.

I think you should pump some more, get some more pressure. I think my double chamber version will perform like that at around 35 pumps, I use about 45-50 normally.

Oh! My PC was still bigger than the ones that you made for your homemade. Dang! Well, I need to perfect the pump, and I might get longer strokes. Also, I need to buy some more PVC glue (that stuff runs otu fast), so I can seal up the whoel thing. Right now Doom I have 6 to7 inch long 3" PVC for the single pressure chamber. Should I buy another end cap, saw the existing PC even more, and attach a new end cap? Or should I leave it. Also, this is a new, but risky idea I just had. I coudl cut it to 4inch long PVC like you did, and then cut the piping on the side where it loeads to the second check valve. I coudl then buy another endcap as well as more reducers and a tee, and I could get two PCS on there, making it as close to your design as possible.

Also- The resevoir I developed holds about 300 oz. There is some over flow, so I am guessing it holds a little more than a CPS 3200 backpack.