How to make a homemade water bong

Well, this method of making a bong is adapted from a method my brothers and I used. However, the materials we used are probably completely out of the question for most people. In this tutorial, I use a 3 liter bottle instead of a water cooler that my dad got from the hospital after his knee surgery. It has a valve with a hose and stuff... But a three liter bottle can work the same way. If your wondering, you can get a three liter bottle from a grocery store. They're most commonly made by Faygo. We used some sort of plumbing piece of the bowl, and it works VERY well, but I doubt others could find such a specific piece without a product name, etc. So, here it is, the adapted water bong tutorial.

You will need:
A two liter bottle.
A three liter bottle.
A brass instrument mouthpiece (trumpet, trombone, tuba) or other bowl.
a knife.
a lighter.
a screwdriver.
a nut (like nuts and bolts)

You can pick up a three liter bottle at a grocery store. They're most commonly sold by Faygo. If you don't know what faygo is, you might not be able to get a three liter bottle. If that is the case, you can use a one liter bottle instead of a two liter, and a two liter instead of the three liter. But it works much better with the three liter for reasons i'll explain below.
First make sure both bottles are empty. Remove the cap from the three liter bottle, and cut the bottle horizontally at the bottom of the bell. At the top of the bottle, it gets smaller and smaller up to the cap. Cut this whole smaller section off. Now take the two liter bottle and cut the bottom section off. Cut right above the "feet" of the bottle. Remove the cap.
Now for the tricky part. You'll need to find a bottle cap (not necessarily a bottle cap from a drink) that will drop into the hole where the cap of the two liter bottle was, but will get stuck before falling through into the bottle. If you need a clearer explaination of what I mean, find the top part of the three liter bottle you cut off, and drop the cap of the two liter bottle into the hole. The bottom of the cap slides down into the hole, and then gets stuck near the bottom. If you can't find a bottle cap of appropriate size, don't worry. The bong will still work, it will just be a little less convenient. Just use the regular cap that screws on instead.
Now you'll need to locate a nut which fits snugly around the stem of the mouthpiece or bowl. Once you find one, put it around the stem as tightly as possible. After that, place the bottle cap on a table, and place the bowl near it. In your dominant hand, pick up your lighter, and in your other hand, hold the screw driver. Use the lighter to get the plastic in the CENTER of the bottlecap hot. As soon as you see smoke (plastic smoke is usually black) stab the molten center with the screwdriver. Make sure you don't make the hole any bigger than the nut. Preferably while the cap is still molten, attempt to jam the stem of the bowl into the hole. The goal here is the get the plastic as tight as possible around the bolt. If the hole is too big, get a new cap and try again. If the hole is too small, repeat the heating and stabbing process. You may find it helpful to stab with the stem rather than the screwdriver the second time. Once you have the plastic around the nut so that the bowl stays in the cap without falling down or through, take your lighter and melt the plastic around the nut. Take extreme caution while moving the molten plastic around the stem so that it touches the stem and the unmelted bottlecap. The idea here is to have the plastic dry, adhering the bolt to he bottlecap with a very strong seal. Once this is done, you've got your bong. Just put the two liter bottle you've been operating on inside the larger three liter bottle, and pour water between the two bottles, filling the three liter bottle a bit more than halfway up.
Just place your herb in the bowl, and pull the two liter bottle up slowly as you hold the lighter on the herb. When you pull up, the volume inside the two liter bottle becomes larger as it rises out of the water, and so the pressure inside the bottle decreases. Since the air outside the bottle is at a higher pressure than the air inside the bottle, air from outside tries to flow into the bottle through the hole in the bowl. But since your burning the weed, smoke inhabits the area around the bowl, so smoke is sucked into the bottle to make up for the pressure difference. Watch to make sure you don't ever pull the two liter bottle all the way out of the water, or alot of smoke will escape. Once you've pulled it up as high as possible, just pull out the bottlecap, (or if you couldn't find a good bottlecap, unscrew the two liter cap your using) and put your mouth over the hole in the top of the two liter bottle, like you were drinking from it. Now, inhale. Sucking in the smoke will cause the pressure inside to go down, because you remove matter from the bottle without decreasing the volume. Since the pressure inside in lower than outside, the bottle will sink in order to reduce volume, so that the pressure will become equal to the pressure outside. Basically, when you inhale, the bottle will sink. It is important that you do not PUSH the bottle down, just inhale and let it sink. Once you can't take any more smoke, or the bottle is all the way down, put one hand on the bottle, then pull away. Make sure you hold the bottle up and don't drop it. If there's anything left in it, then when you drop it the smoke will fly out of the bottle and be wasted. After you exhale, inhale the rest of the smoke, or let someone else. Generally, it is necessary to light the weed and pull up again after each person has a hit. Once you're done pulling the bottle up, it should be a milky white color inside, and be almost opaque. If it doesn't get that smokey inside, try putting more water in the bong.
Some types of 3 liter bottles aren't the right shape for a two liter to fit inside them. In these cases, use a 1 liter instead of a 2 liter.

WARNING: Molten plastic is very dangerous. If it gets on your skin, it is very difficult to remove, and will cause SERIOUS burns and pain. Don't be an idiot when you melt shit.

Hope this guide was easy to understand, happy toking.