This afternoon I am going to go shopping to buy the rest of the parts I need for my Douchenator. But I have a question when I fire it, what kind of wadding needs to be in it, if any at all? I know that a water balloon will be hard to make a perfect 3" each time. You'll see pics (and maybe a video) when I'm done. B)

The best type of wadding for a 3" barrel is a pringles can, with the top rim cut off and placed upside down in the barrel. Balloons do not go in it, they rest above it. The second best item is a tennis ball can and that is placed right-side up with balloons inside. There is a difference, and you'll notice if you try both [the Pringles cans make better seals]. If you don't use wadding, the balloons will either not shoot or barely shoot.

Well, the place I went to buy the 3" pipe had the right stuff, but only in 20 ft. sections, for $32. I only had $17, so I'm going to have to wait until next weekend. And I still need a schrader valve, which I might be able to get Monday. After the douchenator, I'm going to start working on my own designs. :D

If you've got nothing else, a plastic supermarket bag makes an ok wadding, and can fit inside practically any sized barrel. However, as Duxburian said, the better option is a lightweight can of some sort. If your can is a little too small in diameter, try wrapping a few layers of electrical tape around it until you get a good seal.

Wow! And I thought buying in 10' sections was a bit much! the plus side of buying more than you need is being able to use it later on other projects. A 20' section of PVC should last you a good number of Douchenators and a few APHs on top of it.

Good luck.

Ok, It's going to be longer than I expected. Yesterday my rear axle on my bike broke, (the axle, not the wheel) and I'm going to go buy a newer and better one. They're only around $5-$9, but with the money I have, it might set me back another week. <_<

Can't you get your parents to replace broken bike parts? Hmmm...if you can, a creative way to get a schraeder valve would be a puncture your tire and make it look like an accident...then use the schraeder valve from the old bike tire...

A Pringles can? Wouldn't that be too small? I'm using a 3" barrel, and I don't think that would fit. Should I just get a big plastic cup and cut it to size for the barrel?

And what sort of wadding / psi / launch angle should I use to reach 300+ feet?

I got the rest of the parts today and am going to finish it tonight, hopefully I can test it tomorrow. :D

A Pringles can is perfect for 3" PVC. At least the original can size, you know, the most common standard ones. A plastic cup cut to size actually does not work as well, and breaks more easily.

Wadding: Pringles can or tennis ball can or plastic cup [nothing more is needed].

PSI: 60-120 is good, however, you don't need more than 60 or 70 in a war.

Launch Angle: Level for people, 20-60 degrees for long range attack, 60+ for shelling bases. 45 degrees is probably the best for the most range.

I'd say 35-40 degrees is the best for maximum range, even though I know next to nothing about WBLs. With significant fluid air resistance, the projectile's speed will be cut down, and my (admittedly minimal) knowledge of physics says that the maximum height of the trajectory should be half the total range, for an "average" of 45 degrees. If you start off at 45 degrees, then the final angle will be less than negative 45 degrees, so the total range will be less than twice the total height.

Completed:

I'm not sure about ranges, I wasted all of my balloons shooting straight up and I need to get some more.

This is also my semi-official last post. I might come back next year, I'm not sure. But just because I'm leaving these forums doesn't mean I'm leaving soaking as a hobby, I'll just have more time to devote to it and other things. The less forums I visit, the more time I can spend on my hobbies. :D

Nice job! That looks like a beast of a cannon, and you should get some pretty big ranges. Glad to see you used primer and added a pipe for leverage on your valve.

Sorry to hear you're going, it'll be a chore checking up on all the new happenings when/if you come back.

Soak On

I'm actually real glad that someone else took my advice with the torque arm. When plastic valves are cheaper, use them! The pressures we use are well within their limits, and they open much faster than a metal valve with a torque arm.

I cannot find any pressure rated PVC in Canada (3"). We only have drain pipe PVC, that is not pressure rated. What is 3" PVC used for in the US that makes it need to be pressure rated?
~croc~

All systems of plumbing have certain areas that are pressurized. How do you think water travels from the main to your house? Pressure rated pipe is also used for the transportation of waste materials from buildings to processing plants. In fact, most plumbing that isn't metal under ground is pressure rated simply because its more durable. I'd be surprised if you couldn't find pressure rated pipe in Canada. However 3" might be rare. How far do you live from the border? If you can't get pressure rated pipe, don't build the cannon. Better to be safe than sorry.

Soak On

I didnt see any pressure rating on the pipe, it just said "drain-way" on it. I live in the Toronto area, which is close to the border. At my local Home Depot I couldnt find any, but probably, if I look far enough, I will find the pressure rated 3" PVC

I experienced something sort of similiar at my local Home Depot. Apparently all of the fittings are now DWV, although I can still find pressure rated pipe. I haven't been to my local Lowes in quite a while, they have always had a better selection, however I won't be surprised if I find that they too have opted to sell drain pipe. It is cheaper, which means a larger profit. :(

Well, my Lowe's and Home Depot don't have pressure rated 3" pipe. They have cellular core, which can't be used to hold pressure, although you can use it for barrels. I got my pressure rated 3" pipe from Ace Hardware, I don't know how far their stores are spread out though, so you may not have one.

Ace Hardware...I don't think I have one in town. At SSC, I mentioned that my entire homemade build is being put off due to the lack of pressure-rated 3" PVC at Lowes--so we're all in the same boat. However, I was going to go to a different store today, so thanks for pointing out that Home Depot (incredibly far from the city, and a long drive there and back) doesn't have it either. I'm now thinking of either Ferguson's (plumbing), McMaster-Carr (online), or this other plumbing place that I can't think of at the moment. However, I know for a fact that it's available somewhere in town, since we have pressure-rated 4" PVC in the backyard...