very new to everything homemade

[psicicle]

Im not new to doing slight repairs to water guns but I have never used PVC before, when you buy it do you need to saw off parts to get a desired length? Also, what kind of glue should I use for it? I am interested in making that air pressure gun on this website, and I will only have one chance to go to a home depot so I might also want a list of tools I will need.

[Silence]

Welcome to Super Soaker Central, psicicle.

First of all, if possible, try to go to a local Lowes instead of Home Depot--when it comes to plumbing, Lowes has a greater selection of products. In addition, you can order practically everything from McMaster-Carr, and they will also have products such as Latex Rubber Tubing, which is used in CPHs. McMaster is also a reliable source of less common but still necessary parts, including ball valves and check valves, and they'll probably have O-rings too. Of course, I haven't had cause to check out the entire product range yet, so I really wouldn't know...

No matter how you order the materials, you'll need to cut the PVC; a hacksaw should do for that. You'll need primer and PVC glue to attach all the pieces together, and those can be obtained quite easily. To my knowledge, Ben hopes to write a complete homemade-building guide, but that won't be up for quite a while, if at all. Good luck with your APH.

[Ben]

When you first buy PVC, you do not need to cut it unless you need to cut it for it to fit in your car or truck (as I often do). You will cut the PVC when you need to use it.

As for the glue, you could have read the article. PVC primer and cement are used. The primer cleans the PVC and makes it easier to weld, and the cement essentially melts the PVC to the fitting ("solvent welding").

Tools required should have been included. I wouldn't want to use anything less than a hacksaw, a good solid table clamp to hold things steady, and a drill press or hand drill (preferably a drill press).

Also, Home Depots can have very good selection and I think people should know that. Initially I suggested against them in favor or local stores or Lowes, but as of right now my Home Depot has a different selection which is better in some respects (and worse in others). Home Depot does have 4 inch pressure rated pipes where I live, while Lowes does not. Check out both and other local stores as well. Checking and shopping around is the thing to do.

Good luck with the contruction. Let us know if you have any other questions.

[Silence]

Ben, what's your opinion when it comes to McMaster? I know they might have a good selection, and they probably have excellent prices, but how much does shipping usually charge for Maryland? I've been looking at the site, and there's an excellent selection of products...

Also, should people use O-rings with circular or with rectangular cross-sections?

[DX]

I personally would only use McMaster for parts you can only get there, such as LRT. Hardware stores vary in their selection, in NJ:

Lowes: Has check valves, ball valves up to 1", PVC pipe up to 6"

Home Depot: Has ball valves up to 1", PVC pipe up to 6"

Sears: Has ball valves up to 1 1/2", PVC pipe up to 4"

Local stores: Have O-rings of like all sizes, ball valves up to 4", Schrader valves, PVC pipe up to 4"

Also, should people use O-rings with circular or with rectangular cross-sections?

Cross sections? O-rings are one shape, circular rim with an empty center. I have no idea what the cross sections are, or what the heck an O-ring with a "rectangular cross section" is.

[Ben]

Ben, what's your opinion when it comes to McMaster? I know they might have a good selection, and they probably have excellent prices, but how much does shipping usually charge for Maryland? I've been looking at the site, and there's an excellent selection of products...

McMaster-Carr is good, but they can be overpriced. They also can be cheaper, so verify the prices against your local ones. Shipping varies however. Typically it is about the same as the 5% sales tax here, but on longer objects such as lengths of pipe, the shipping would be more expensive. I believe they do have a shipping calculator and let you choose which type of shipping you would want, so check that out.

As for the different varieties of O-rings that McMaster-Carr offers, I don't know too much about the difference between them. Circular cross sections appear to be the most straightforward. I'd be worried that the square cross section ones would rotate and not seal as well.

[Silence]

Thanks...all that information saved me quite a bit of trouble with having to cross-check prices ! I'm sure I can make a few trips to Lowes, though maybe not to Home Depot or the local plumbing stores...

I'll just go with the standard circular-cross section O-rings, as they'll have a better seal...though I don't think either type will roll if you have electrical tape surrounding them. Actually, the circular ones seem to be more likely to roll, but it really doesn't matter.

@ Duxburian: the O-rings with rectangular cross sections have rectangular rims. I wasn't overly aware of their existence until I saw the page at McMaster-Carr.

[psicicle]

okay, cool. Also, it would be helpful if I knew how many feet of each kind of PVC I would need to buy and then how long it is after sawing because I don't want to end up with some kind of out-of-proportion water gun. Also, with the APH, how do you fill it and where is the pump?

oh yeah, on the picture it shows this black turning thing, is that the trigger?

another question: what is a reducer?

[DX]

Also, with the APH, how do you fill it and where is the pump?

Below is a twist-off cap, which I highly recommend as a way to fill the reservoir.



Below is a picture which shows you where the pump goes: between the first and second check valves [one-way valves]

oh yeah, on the picture it shows this black turning thing, is that the trigger?

That is a PVC ball valve, which acts like a trigger [you flip it in order to shoot]. However, I recommend a metal ball valve if you want to be able to flip the valve fast enough to use it like a trigger. PVC valves are extremely slow.

[psicicle]

thank you, also in addition to all this, when it says 3" is that inside or outside wall thickness? Also, what wall thickness should I have?

I just looked at the price and it said 46 dollars a foot of PVC that is 3 inches inside diameter, it shouldnt be so expensive should it?

[Silence]

Reducers are fittings that essentially convert the tube diameter; say, from 3" for the reservoir to 3/4" for the pump.

Don't worry about the PVC wall thickness as much as the rating. Schedule 80 is probably the most suitable, and I'm thinking of using weak but cheaper ABS for my reservoir, which won't be holding any pressure. The PVC you saw shouldn't be so expensive, and it might have been Schedule 120 or something, which is excessive.

[DX]

I just looked at the price and it said 46 dollars a foot of PVC that is 3 inches inside diameter, it shouldnt be so expensive should it?

10ft of 3" pipe can be obtained for $8-14 depending on the store. Make sure it is the right schedule and is pressure-rated. 3" pipe is 260 PSI @ 73 degrees F.

I'm thinking of using weak but cheaper ABS for my reservoir, which won't be holding any pressure.

You could just use non-pressure rated PVC, which is also dirt cheap.

[psicicle]

umm what does the schedule mean? I tried to find it but I couldnt.

.................................................< because it says my message is too short

[Silence]

The Schedule rating measures the strength of PVC pipes, and I'm assuming it's on the bar code tag on each piece of tubing. If it isn't there, ask somebody at the store.

It's been a long time since I've handled PVC...

[psicicle]

1 washer that fits in 1/2" ID PVC joints

what kind should it be? I see sealing, shimming, cushioning, fender, fixturing etc washers! What excactly is the difference between all these?

Also, in mcmaster is this cap hollow at the end or is it a cap?
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