WR Home 
Launch Reports 
WR Construction 
Fin Construction 
Altitude Measuremt 
Search & New 

 bottom of page

Other uses of PET bottles

Every serious water rocketeer develops a sensitive feeling for PET bottles over time - too often he finds himself scanning his surroundings for empty PET bottles apt for rocket or other use.

Once in a while I hear from new original uses of PET material, which are presented here.



rotary kite

Rotary Kite

Here is another creation of Andrew Kinsman (
"Made from wooden sticks, foam, and four 2-liter PET bottles, glued together just like bottle rockets. This one weighs in at 5oz.
Assembly: connect four bottles after sanding the contact points, glue them with gorilla glue. Insert several foam ovals, smallest dimension is 2.5 inches. This assembles a tubular oval. Insert a nail in the sticks and use safety pins, or fish line swivels on the nails to form the necessary bearings so the kite can spin. Connect two lines, one to each bearing. For very high winds replace the wooden sticks with carbon fiber arrow shafts. Insert short wooden plugs to push the nails into. Whip the ends of the wooden sticks with thread and apply super glue to keep the nails from splitting out due to the side forces. Fishing line swivels work best as lines don't twist up. Use 1/2 inch thick foam if you can find it, 1/4 inch for inner ovals. Use 1 inch foam and split them into 2-3 ovals with a sharp non-serrated meat carving knife. Less glue is better to keep the kite lighter. The two foam circular disks on the ends add gyroscopic stability and protect against damage. Make them only slightly larger than the wing.
Launch the kite by spinning the top of the horizontal kite away from the pilot. This kite is extremely maneuverable and is best used over water to save on repairs. It likes wind in the 10-15 MPH range, and has flown in wind over 40 MPH. Landing is difficult, best dunked in water, or have a friend put one arm over each string and walk towards the kite and catch it. If someone helps you launch it, never let them spin the top towards the flyer!!! This causes great lift towards the ground, and sure destruction."     (November 2005)
Thank you, Andrew, for this very creative idea. Flight reports welcome.
More on rotary kites on Andrews Homepage. Or here. And here.

pop bottle windmill


David G. Leatham from Anacortes, USA, found this nice-looking windmill from soda pop bottles in Renton, WA. Instead of guy wires, the bottles on the plastic pipe keep the support from bending. (May 2005)

Doll's Washing Mashine

Doll's Washing Machine

Last christmas my 8 year old nephew Joel asked me to help him build a Doll's Washing Machine for his sister Eva. I promise that I have not influenced him to use a PET bottle - he all by himself wanted to use a Volvic water bottle. We cut away the bottom of one bottle, shrank it a little to make it fit into another bottle top. A cardboard box was used as bearings, and we even used a cordless drilldriver as a 2 directional motor (click here to see it move)! It was a big success on her birthday: "Eva laughed herself silly!"

Chain Reaction

Chain Reaction (Kettenreaktion)

by Tobias Horriar. This is the most elaborate construction using PET bottles that I have seen so far. It is an apparatus using not less than 137 different effects on an area of 1 m2, one firing the next. Here are just the first 13, translated form the original page:
Everything begins with igniting a sparkler [1]; a PET bottle (!) catches any hot sparks. The sparkler sets fire to a thread [2] and the attached lever [3] falls down. The thread was soaked with ammonium aluminum sulfate, NH4Al(SO4)2 to prevent catching fire. The lever presses a switch [4] by its weight, so that a high current from a thick battery [5] runs through a very thin copper wire [6]. This wire gets melted. Thus a further lever [7] falls down and with it a tube [8], which rests on a photoresistor. Now the light of the two bulbs [9] may fall on the photo-sensitive area and the photoresistor's resistance drops. Therefore an electric motor [10] starts running and pulls another lever [11] upward, whereupon a wire is fastened; now a piece of aluminum foil [12] is affected. Wire and foil form a short-circuit with a strong transformer and thereby a hole is burnt into the foil. By this hole water from a PET bottle (!) [13] flows into the glass below. A lever is held up by stacked sugar cubes, which lowers itself as soon as the sugar cubes are dissolved. This goes on until effect # [137] here (in German, click "Kettenreaktion". Use babelfish to translate the entire site).

Cola Gondola

by Andrew Kinsman (
"It is made from forty 3-liter bottles with each tube pressurized to 5 PSI to add rigidity.  It weighs only 14 lbs and is really easy to car-top at 12 feet long."
Thanks, Andrew, great idea! Looks like fun.
More on Gondola construction on Andrews Homepage. (HPB)

Enhancement: Why not pressurize to 80 psi and release the air under water for a good but short forward thrust? (kidding)   June 2004

Luka with a PET KnatterbootCopper Coil

Putt Putt Boats (Knatterboote)

On Freiburg's Model Fair in May 2004 a school organized a competition. Every participant had to build a Knatterboot. Luka Fischer (left) made one from a PET bottle, cut in halves, nicely painted in red and gold. The right pic shows the copper tube coil, heated by a white tea-candle underneath, protected from wind with the aluminum shield. Both ends of the copper tube end astern in the water. The tube is filled before start with water, the candle brings it to a boil. The first steam bubble drives water out of the ends, giving the boat forward thrust. It develops a pulsating water stream out of the exhausts, with a "putt-putt" or "pop-pop"sound (German: knattern). The fastest boat won, of course, but I didn't stay long enough to see the race of all of the 60+ boats). Click here for an article how to build one.

Three more Knatterboote

Left: a PET bottle used as bow (boat front).
Middle: made from a herring can
Right: hull made from foams in national colours. Sail says "environment".

hovering CD

Model hovercraft from an old CD

This idea was discussed by Tom Benedict and David Leatham in the WR list. I built it with kids - here you see the final product, being blown way across the floor.
You may ask "Where is PET used here" ? Click here for the answer and more pics on construction.

1          1 insects fly in here
1 v v 1
1 v v 1
1 v v 1
1 v v 1
1 1 "b's" trapped in the bottle
1 b b 1 can't find exit
1 b 1
1xxxxxxxxxx1 bait in bottom
1xxxxxxxxbx1 (+ drowned "b")


Wasp & Fruit Fly Trap

Rob Vida wrote in October 2003:

"We have a bit of a problem here with wasps that like to spoil barbq's and picnics by buzzing around the food and people in a threatening way. Very painful stingers back up the throats. Canned pop is a dangerous thing as they hide inside to get the pop and then sting your mouth. ANYWAY, we make traps from 2L bottles with a bit of pop in it and it works great. Just cut the top third of the bottle off, turn it over and put it back in the open end of the base (v). Seal it in place (tape, glue, etc.) put in some pop or even better things like smelly old juice, skunky beer or whatever smells strong but suggary (xxx)."
Thanks, Rob, for this tip. We've got annoying wasps over here, too. They'll soon learn about this ....

David Leatham added: "This same trap is great for fruit flies - use vinegar as bait.
My neighbors have 5 Apple trees and the only pickers are the wasps...U can
practically 'breathe' fruit flys here!".   Thanks, dl.

Catapult for humans

This is no "other use" of a PET bottle, but a nice and exciting "other use" of our Water Rocket propulsion technique. The courageous lady on the picture is being thrown into the swimming pool vigorously.

Technical data

water fill:

60 l


10 bar


ca. 3 G

distance thrown:

8-10 m

shoot frequency:

down to 1/min

water exhaust speed:

160 km/h

required pool depth:

3 m

Rocket car "CokeAbout"

Rocket Car

from David G. Leatham (Dec 2002). He wrote:
"'Coke About' is a 3L Rocket Car.  My 1st try. Finding that CD's fit on the bottle tops so well gave me the idea.  I've always wanted to try a car and felt the wheels should almost be fins.  These wheels will easily break but can be replaced very quickly. The funnel on the front is to test another idea - push air thru a little green toy siren that is pushed in the nose. Also there is a scoop up top to exhaust the air from the siren. Could not resist using up those toy eyes I'd been saving.
It uses PET in several unique ways: the rear assembly swivels for a slight suspension action, and there are spring washers to steady the wheels."

PET snail trap

Snail trap

October 2002: A lady in the rural Allgäu region (pretty close to the famous castle Neuschwanstein) showed me her way of keeping the snails away from her salad in the garden. She tried many other tricks, nothing worked. And now:

allgäu lady
"This installation is perfect!"

 RC ship from a coke bottle

HMS Coca Cola light

On the Freiburg model fair in June 2002 I saw this nice ship from an experienced modeler who was tired of building "regular" ships. So he started searching for more original designs like this ship "Coca Cola light".

coke ship inside

For this photo, he opened up the cover. In black on the right the servo for the rudder, in brass, left of it, the drive motor.


Submarine U4711

From the same artist: although it is not made of PET, I include this interesting submarine ship U4711, made from a canteen (military WW II water bottle). The periscope is used as the antenna.

4711 is a famous old fashioned perfume in Germany.

submarine from a hot water bottle

From the same artist: although it is not made of PET, I include this interesting "Nessie" type submarine from an old copper hot water bottle.

Both these submarine creations do really swim and dive.

 bicycle fender

Bicycle fender extension

This is a creation of my own. Modern bike manufacturers save material even on the fenders. Mine was too short; when driving in the rain, road dirt kept splattering on my stuff on the rack. So, in May 2000, I lengthened the fender a bit with this crumpled piece of PET and 2 office clips. No dirt on top of my rack any more. This fender extension is very light and indestructible!

dish from PET

Dessert dish (and more)

This nice dessert dish comes from Japan over Thailand to us.

Many more interesting PET ideas like a plant pot, aquarium, raft, wind catcher (Windrad), even a kajak on Pitan Singhasaneh's Thai page.

Maybe someone sends us a picture on this?

Intellectual activation toy for dogs

(yes - dogs do need to use their brain cells!)
Brad Calvert from the WR mailing list sent me this nice application:

Use a large PET-bottle of thicker quality, not the thin, flimsy ones. The bottle should be big enough so your dog can't grab it with its teeth. Cut the bottle just below the screw fitting (otherwise the dog will be able to chew it up...) and sand the edges so they wont cut your dog.
Put some treats in the bottle; sausages or meat balls cut in pieces, dog food pellets of appropriate size. Then watch your dog try to get the treats out of the bottle.
It's great fun to watch, and after some false starts your dog will get the hang of it and, with time, become quite expert! To make it easier in the beginning, cut the pieces small enough so that all three dimensions (length, width and height) are smaller than the diameter of the opening.
Our dog has learnt to roll the bottle into a corner and then set it spinning with her paws. When it hits the walls it's jackpot-time!

Brad has a list of "Other PET uses", well worth to view. It is on and includes amongst many others: Rain gauge, Terrarium, Submarine, Timber protector, Hourglass, Mini-greenhouse, Flying insect traps (the best).

 smilie, waving

Did you see any other funny non-rocket use of PET, our main water rocket material?
If so, do not hesitate to send me a digital picture and some words of explanation. I am happy to publish it here.





top of page

Stand / Last Revision:  22.05.2010

PageHits since 11.01.2004