Picture of Soda Bottle Water Rocket
In a couple of hours (or less) you could make this water rocket! Water rockets use water and pressurized air to launch a soda bottle(s) 100's of feet into the air. This instructable will NOT cover the launcher. I hope to later come back and write up an instructable for a launcher. There are many websites with water rocket plans (and launchers) part of the fun is to experiment and come up with your own designs. Feel free to modify, improve, experiment with this instructable and post your results in the comments. The original inspiration for this rocket was from the magazine called "MAKE Magazine" (makezine.com). Issue #5 has full instructions also.
Remove these adsRemove these ads by Signing Up

Step 1: Materials

Picture of Materials
List O Materials...

> 2 Soda Bottles (empty)
- Note: There are slight differences in the openings of the bottle depending on the soda brand. Pepsi is just a tad smaller than Coke. -
This Instructable is set up for 2 liter sized bottles - feel free to adjust for any size though.

> 1 sharp knife (kids get your parents help here!) I prefer X-acto brand for cutting foam core.

> 1 Large sheet of Foam Core (I prefer Black, but any color will do). Foam Core can be found at almost any arts and crafts supply store. To learn more about foam core try wikipedia: http://en.wikipedia.org/wiki/Foamcore

> 5 Min Epoxy (This stuff is nasty! Do not inhale, and use in a well ventilated area. Do NOT get it on your skin or eyes, or hair, etc... read all safety warnings before using.) Feel free to experiment with other glues. This can usually be found at any hardware store - kids, ask your parents for help with this glue.

> 2 (or more) Markers - I used Sharpies, one black and one Silver

> Clear Shipping Tape - It's thicker than regular scotch tape and about 2" wide.

> 2 (or more) cans of spray paint - Pick your own favorite colors!

Step 2: Step One - cut bottle

Picture of Step One - cut bottle
Peel all labels off of the bottles.
Measure up from the bottle about a Third and cut the bottle. Try to keep your cut line as straight as possible. It may help to mark a straight line around the bottle first. Be sure to recycle or reuse any scrap pieces.

Step 3: Bottle Merge

Picture of Bottle Merge
Take the cut bottle from the previous step and insert it directly over the bottom of the other bottle - this becomes the nose cone of the rocket. Try your best to keep everything straight. If you put the nose on crooked, your rocket will fly crooked. Place the nose cone on loosely at first, then gently press down until firm. Turn bottle upside down and let it drop on a hard surface several times. If you press the nose cone on too hard, you'll start to get "crinkles" in the plastic. Crinkles are bad.

Step 4: Tape Bottles together

Picture of Tape Bottles together
Once the nose cone is on tight (but not too tight) use the clear shipping tape to tape the seams. Try to keep tape smooth.

Step 5: Cut the Fins

Picture of Cut the Fins
Next you gotta cut some fins to keep your rocket flying straight. I will attempt to upload a PDF file here, so that you can use it as a template. I used a Pepsi bottle, so again, you may need to adjust the curves to fit your bottle. Kids - this is the step that you will need your parents help. Parents... cutting foam core can be tricky. The key is to cut one time all the way through in a smooth motion. You'll need to press hard to make sure the knife is all the way through the foam core. If you feel more comfortable using a utility knife by all means. Be Careful!

Please! Experiment with your own fin designs. I chose a more squared off design, but you can use curves if you like, etc... I chose 3 fins. You'll need a minimum of 3, no more than 4 (unless you really really want to!). If you do 3, you need to split your bottle into 3rds, which equals 120 degrees. I'll try to upload a second PDF file with a 120 degree template. 4 fins, you'll just need 90 degrees.

Step 6: Fin supports

Picture of Fin supports
This step may not be needed, but I figured better safe than sorry...
Using some of the scrap pieces of foam core, I cut 6 small triangles. (approx 1" x 1.5"). These will be added to your fins later for extra support.

Step 7: Attaching the Fins

Picture of Attaching the Fins
Ok, this is the tricky part. Open your adhesive (or glue of your choice). Squeeze out a small amount (enough to do one fin). Mix the epoxy with a scrap piece of foam core (this will be your "brush" too). PRE-Mark your bottle (with the marker) where you want your fins to line up. Make sure the fins fit your bottle BEFORE putting any glue on them. Trim, or adjust if needed. Apply the Epoxy to your fin, and attach it to the bottle. WARNING: This step requires patience! 5 minutes is a LONG time. If you can figure out a way of setting up some clamps, more power to ya. While holding the fin, don't let it shift... you will be able to move and adjust the fin while the epoxy is drying, but once it starts to set, it gets difficult to adjust. You'll feel it start to set. Once it gets to the point where you can't really adjust it anymore, you can place the bottles and fin, on the table to set without holding it.
Prepare your next "glob" of glue for the next fin. REPEAT for all of your fins.

Step 8: Glue your Fin Supports

Picture of Glue your Fin Supports
This is the added step for extra support. Glob out another dab of Epoxy and glue your triangle to the bottle and the fin. Glue the Supports on each side of each fin. Wait approx 10-15 minutes to be sure Epoxy has set.

Guess what... Your done all of the assembly at this point!!
You could take this rocket to the launcher at this stage and let it rip!
BUT... it's kinda messy looking isn't it?
One more step...

Step 9: Paint and Details

Picture of Paint and Details
This is where the spray paint comes in.
I used BLACK and a Bright Green so that the rocket would be easy to spot while up in the air!
Decorate your rocket any way you like! Flames, spots, checkers, glitter, etc...
Use your extra markers to add any fine details or words (I put H20 on mine so everyone would know this is a water rocket). Add some pin stripes, etc...

(note: as you can see from this photo, I also added some additional tape to the fins for extra support. Do this BEFORE painting.)

Perhaps, I should have mentioned this before, but this rocket has no parachute! What goes up, must come down.
DO NOT launch this rocket near people, a crowd, small animals, streets or cars or houses... in other words... take your rocket out to the middle of nowhere and launch it in a safe place. Make sure everyone knows there is no parachute and that this rocket will be crashing to earth at a high rate of speed. I wouldn't want to get hit by it! The rocket will probably fly higher and farther than you think.

Step 10: Links and Video

Here are some additional links that may help...
Youtube video of my rocket and a group of others from the MAKE:PHILLY Bar-B-Que. (I'll try to embed this video also).


Make Magazine - Issue #5


1-40 of 328Next »
Dk12131 month ago
Can I add a parachute on this and if so how?

There are lots of ways you can attach a parachute to a water rocket. I would recommend something like an air flap or timer system, or if you're willing to spend some money, a flight computer or magnetic apogee detector.

Here is a very reliable timer based version:https://www.youtube.com/watch?v=bVpJqoHQBm0

Here is a magnetic apogee detector version:http://www.aircommandrockets.com/construction_7.htm

another one: http://www.uswaterrockets.com/documents/LaunchPad_AlTImeter/manual.htm

he is actually right that's a couple of wayz

yes u can and I will make an instruct able in about a month on how so keep posted!

cyenobite (author)  Dk12131 month ago
You can try. I didn't feel the need, as it is fairly durable (unless it crashes onto pavement or hard dirt, the nose might get caved in, but with mine, I just pulled it, and the nose popped back fine. You can *not* tape the nose portion of the rocket to the main body, and loosely attach it (with tape and string) to the body, then the parachute could be stored in that loose nose section. In theory, when it hits the apex, the nose will 'fall' off and the parachute will deploy. I won't guarantee this will be a good plan. But feel free to experiment. If it works, please post back here and let us know! Good luck!
Flashdance518 days ago

guyz I made the rocket don't have pic because I used a launcher and it broke cause it went really high.

Simo2451 month ago
GhostWolf761 month ago

pics of my soda bottle water rocket i made for 2 of my nephews. tried to make it look like Iron Man

cyenobite (author)  GhostWolf761 month ago

Looks Great! Always cool to see photos!

GhostWolf761 month ago

hey cyenobite, i was wondering what type of tape did you use to give extra support for the fins before you painted the rocket?

cyenobite (author)  GhostWolf761 month ago

hi ghostwolf76, I actually did not use any tape at all when it came to the fins. I just glued them on using the epoxy, and they I added the small triangles for the extra support (also epoxy). The only place I used the shipping tape was to seal the one bottle top onto the other bottle. Hope that helps.

it step 9 it shows the tape and you said you put tape for extra support on the fins before you painted it.

cyenobite (author)  GhostWolf761 month ago

Oops sorry, you are correct. (I built this almost 7 years ago! :)
If memory serves, I just used the same shipping tape, cut into smaller pieces. I think the shipping tape was good and strong, and didn't stretch much (like masking tape or duct tape would be too flexible). Hope this helps. Good Luck!

ah thanks. i used electrical tape but as soon as i painted over it, the edges and corners curled up lol

kevinw151 month ago


dahlias87991 month ago
Hello, this is a really cool rocket design. I wanted to know how far it travels because I have to make one for a school project and we are graded on the distance. Thanks so much!
rosa9871 month ago
Dk12131 month ago
jordanb72 months ago
fungdoodle782 months ago
Hey I have to make this fort 8th grade end of year Honors Geometry Project. My teacher gave no take home instructions. Now, after making one, I am debating if you are supposed to cut the bottom of the bottle off and then tape the cone on, or leave the bottom off, and then tape the cone on. Some one help!!!
cyenobite (author)  fungdoodle782 months ago
Hello Fung, Good luck with your project. If I understand your question... you have to leave the bottom on the one soda bottle, and put the cone on top of it. There is a LOT of pressure buildup, and I don't think any amount of tape or glue would prevent leaks if you were to cut the bottom off of the main bottle. If you want to try it, by all means, but I can't see it working well.
Coolkat1226022 months ago
I thought that this was a very difficult project and I probably won't do it again but it was fun. I did it with a class and that made this much easier cause we could bounce ideas off of each other to help make this easier.
Tre-AnthonyL made it!9 months ago

it was hard but fun

cyenobite (author)  Tre-AnthonyL3 months ago

Awesome paint job!

HooIigan3 months ago
So I just made one last night with it being due today (I'm a huge procrastinator) and let me say it turned out awesome. Didn't take long to do, maybe 2 hours at the most. Pretty easy to follow instructions and overall just great. I'll post a picture of it later.
cyenobite (author)  HooIigan3 months ago
Awesome! Glad it all worked out for ya!
SamirR5 months ago

cool design

really came in handy with a school project but what powers it and how does it get powered

Barrel Racer9 months ago
Im doin a rocket like this for a Physics project. We have to use a parachute. Where would we put a parachute on a rocket like this n for it to work?
DatCorgi10 months ago

When launching it is it safe to put the cap screwed onto the top?

starstruck0118 made it!11 months ago

Here is a picture of my rocket. Thanks, again cyenobite!

cyenobite (author)  starstruck011811 months ago

Awesome! Nice Work!

I'mP cyenobite10 months ago

do you think you can make an instructional video or send me a link to a video on how to make one please?! =>


etison62110 months ago

Hi, I have to make one of these for school. The challenge is to keep it up in the air for as long as possible. Any tips for that?

My eighth grade science class is making these. I can't wait to see the finished product and see it launch!!!!

kilans made it!10 months ago

this is awsome i love to make stuff life this

kilans made it!10 months ago

this is awsome i love to make stuff life this

starstruck011812 months ago

Thank you cyenobite. This was very helpful. I made the rocket, but still did not paint it. I will post a picture soon.

kildevil1 year ago

I'm making this rocket but i don't get how to fly this do you need to use a pump or ???

kildevil1 year ago

I'm making this rocket but i don't get how to fly this do you need to use a pump or ???

1-40 of 328Next »