How to Build a Huge Water Rocket




About: We're a small group of students and we have been building water rockets since 2011.

Do you want to build your own, two meter large water rocket?

In this tutorial we'll explain everything you need to know about it!

We'll not only show you how to build the pressure vessel, but also show you the construction of the parachute mechanism and a suitable launch pad.

The tutorial is split in five steps:
Step 1) Construction of the pressure vessel segments
Step 2) Construction of the launcher and the nozzle
Step 3) Pressure test and assembly of the pressure vessel
Step 4) Construction of the parachute mechanism (Phoenix 5)
Step 5) Preparations, safety aspects and launch

Additional: Step 6) A list of all materials you need


Be careful with adhesive based on polyurethane. Always wear gloves when working with it, and let it dry outside. Pressurized water rockets are dangerous. Keep distance to it and make sure there are no animals or walkers nearby.

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Construction of the Pressure Vessel Segments

In the first part of this tutorial we will show you the construction of the pressure vessel segments.
For the best results, you will need to use a single type of bottle for the entire rocket. We recommend that you find narrow bottles with straight sides. Bottles with textures or patterns molded into the sides are not well suited for this type of rocket. To simplify the construction of the rocket, we will make the rocket in three short pressure vessel segments, which we will connect together later. To glue the bottles together we use an adhesive based on polyurethane. We recommend PL Premium Construction Adhesive, but there are thousands of different adhesives you can try if you prefer to use something else.

Step 2: Construction of the Launcher and the Nozzle

In the second part of this tutorial we will show you the construction of the launcher and the nozzle.
The launcher is a simplified version, built from three components: the stand, the gardena system, and the trigger.
The stand can easily be made of wooden planks.You should drill some small holes so that you can anchor the launcher to the ground. If you want the launcher to last for a long time, you should paint it to make it waterproof.
The nozzle is made of a Gardena tap nut adapter, into which is glued a bottle-cap with epoxy resin.

Step 3: Pressure Test and Assembly of the Pressure Vessel

In the third part of this tutorial we will show you how you can pressure test your segments and the assembly of the pressure vessel. For the pressure test, the segment should almost completely filled with water. Screw the nozzle onto one side of the segment, and on the other end a bottle cap. The test should always be performed outdoors behind a barrier, so that in the event of an explosion no one gets hurt. Once you are ready, you can start increasing the air pressure using the hose system of your rocket launcher. We currently test our segments to 130 PSI. An optional Gardena Regulator Valve allows the pressure to be released after a successful test,
but you can also use your tire valve for this purpose. If all of your segments and the nozzle have passed the pressure test, you can connect the individual segments with connectors called Tornado Tubes.

Step 4: Construction of the Parachute Mechanism

In the fourth part of this tutorial we will show you the construction of the parachute mechanism.
The outer shell of the parachute deploy system consists of a bottle, the same type used for the pressure vessel segments. Two round plates made of the same material as the fins are glued into the housing using a hot glue gun. The shaft of the Tommy Timer is bend at the middle with two pairs of pliers. After the paint has dried, you can attach the timer to the housing by means of a cable tie.

Step 5: Preparations, Safety Aspects and Launch

In the fifth and last part of this tutorial we will show you the launch and explain the preparations.
Selection of your launch site:
-empty fields or meadows
-far away from houses, streets, trees or electrical wires
-In some cases you will need a permission of a competent authority

Take into account the weather:
-Don't launch in strong winds
-Don't launch in thunderstorms
-A few drops water from above have never hurt a water rocket

Safety aspects:
-Safety glasses are a must
-Keep distance to the pressurized rocket
-Keep an eye on walkers, children and animals

Step 6: Bill of Materials

Here you'll find a list of all materials we've used for our water rocket.

Step 1: Construction of the pressure vessel segments

  • 6 Bottles (no patterns, straight sides)
  • adhesive based on polyurethane (for example PL Premium by Loctite)

Step 2: Construction of the launcher and the nozzle

Step 3: Pressure test and assembly

6 Bottles (no patterns, straight sides)

3 "Tornado Tubes"

Plastic plate

(Optional) spray paint

Air pump

Step 4:Construction of the parachute mechanism

2 Bottles (no patterns, straight sides)

1 Bottle (thin-walled)

Wind-up-toy (Tommy Timer)


Table tennis ball

Rubber band

Cable tie

Parachute (buy or build one)

Step 5: Preparations and launch


Things That Fly Challenge

Runner Up in the
Things That Fly Challenge

1 Person Made This Project!


  • Skateboard Contest

    Skateboard Contest
  • Make it Move

    Make it Move
  • Teacher Contest

    Teacher Contest

46 Discussions


3 years ago

will this fly with 75psi?


4 years ago on Introduction

I didn't think that a water rocket could be so cool. You changed that!!!

Uber-Ingenuous timer mechanism for chute!!

1 reply

4 years ago on Introduction

Can you explain a bit how did you attach your camera to the rocket? and what model of camera did you use?

1 reply

We currently use the DVR #808 #16 V3 with wide angle lens for onboard footage.
In the video embedded above we used the "FlyCamOne HD", but our new camera is a lot better. We simply attach the camera with a piece of duct tape. this works perfectly fine.


4 years ago on Introduction

Brilliant. Well done...

What sort of pressures are you achieving with fiberglass reinforcing and are you using more exotic materials like carbon fiber ?

1 reply

Hello banman11, thank you. :)

With fiberglass or carbon fiber reinforcement you can launch at about 230psi, but you can also try to use more layers to increase the stability of the vessel even more.


4 years ago on Introduction

Great job! The best part is that no pyro is used, so DHS doesn't come kicking your door down.