2-Liter Soda Pop Bottle Launcher
Supplies needed to build one 2-Liter Soda Pop Bottle Launcher
1/2" PVC Pipe 4 feet (48 inches) of 1/2" Schedule 40 PVC pipe
1/2" Threaded PVC Sprinkler Riser 1 each — 4-inch x 1/2" Threaded PVC Sprinkler Riser
1/2" PVC End Cap  1/2" PVC End Cap  1/2" PVC End Cap 3 each — 1/2" PVC End Caps (unthreaded)
1/2" PVC T-Joint 1 each — 1/2" (slip) x 1/2" (slip) x 1/2" (threaded) PVC T-Joint
1/2" PVC T-Joint 1 each — 1/2" x 1/2" x 1/2" PVC T-Joint (all slip or unthreaded)
1/2" PVC 90° Elbow 1 each — 1/2" x 1/2" PVC 90° Elbow (all slip or unthreaded)
Tubeless Tire Valve 1 each — Tubeless Tire Valve (available from a tire store)
PVC Cement PVC Cement (clear)
Teflon Plumbing Tape Teflon Plumbing Tape
Heat Shrink Tubing 3 inches of 1-inch diameter Electrical Heat Shrink Tubing
2-Liter Soda Pop Bottle 1 or more Plastic 2-Liter Soda Pop Bottles
Note:  All PVC pipe and fittings should be schedule 40 irrigation pipe rated at 125 PSI or higher.
Tools Needed
• Hack Saw or Pipe Cutter  • Electric Drill   • 9/16" drill bit  
• Sand Paper (medium grade)   • Sharp Knife or Box Cutter   • Air Pump (with pressure gauge) 
Making the 2-Liter Soda Pop Bottle Launcher
Step 1 — Cut PVC Pipe
   3-inch x 1/2" PVC Pipe 3"    5-inch x 1/2" PVC Pipe 5"    10-inch x 1/2" PVC Pipe 10"    10-inch x 1/2" PVC Pipe 10"    20-inch x 1/2" PVC Pipe 20"
Measure the 4-foot PVC pipe marking lengths of 3", 5", 10", another 10", and the remaining length should be 20 inches. Using a hack saw or pipe cutter, cut the PVC pipe to these lengths. Use a knife, box cutter, and/or sand paper to remove any uneven material from the ends of the pipe segments.
Step 2 — Create Support Legs     Support Legs
Take the unthreaded T-joint and two 10" pipes. One side at a time, apply PVC cement inside the straight-through openings of the T-joint and slip a 10" pipe into each side. Apply PVC cement inside two of the end caps and place them on the ends of the 10" pipes.
Step 3 — Create Main Section     Main Section
Take the threaded T-joint, the 5" pipe, and the 20" pipe. One side at a time, apply PVC cement inside the straight-through openings of the T-joint and slip the 5" pipe into one side and the 20" pipe into the other. Place on a flat surface. Apply PVC cement to one opening of the 90° elbow. Insert that opening of the elbow onto the end of the 20" pipe, taking care to keep the T-joint and the elbow flat on the surface and pointing in the same direction. Apply PVC cement to the other opening of the 90° elbow and insert the 3" pipe.
Step 4 — Install the Riser     Main Section with Riser
Using the hack saw, cut the threads off one end of the 4" sprinkler riser (about 1/2" of the riser). Remove any uneven material from the end of the riser with a knife, box cutter, and/or sand paper. Using sand paper, sand the last 1-1/2" to 2" of the riser pipe on the end without threads until the pipe has a slight taper. Wrap the riser threads two or three times with Teflon plumber's tape, then tightly screw the riser into the threaded T-joint.
Step 5 — Tight Fit for the Bottle     Riser with Heat Shrink tubing
There should be a snug fit when the 2-liter bottle is placed on the riser; otherwise, sufficient pressure cannot be applied to the launch system. Place a 2 to 3 inch piece of electrician's heat shrink tubing over the riser. Blow with a hair dryer until the tubing shrinks and snuggly conforms to the taper of the riser. Tape the bottom end of the tubing to the PVC pipe using electrical tape (the bottle will sometimes pull the tubing off the pipe if the tubing is not taped). Duct or electrical tape may be used in place of heat shrink tubing, but it tends to not seal as well due to the seams created by the tape overlap.
Step 6 — Install the Tire Valve     Valve Stem in Cap
Drill a 9/16" hole in the center of the remaining end cap. Insert the valve stem through the hole and fit the valve stem's lip or groove around the hole. Apply PVC cement to the inside of the cap and the end of the 3" pipe. Place the cap on the pipe making sure it is firmly seated; the end of the pipe should firmly press the valve stem's ball against the inside of the cap, thus forming a tight seal.
Step 7 — Attach Main Section to Support Legs
Apply PVC cement to the T-joint in the support legs and to the open end of the main section. Insert the main section into the support legs taking care to align the main section so that the riser is perpendicular (at a 90° angle) to the support legs. The riser should be pointing straight up when the assembled bottle launcher is placed on a flat surface.
Step 8 — Allow Joints to Cure
Follow the directions on the PVC cement. Typically, the cement needs 2 or more hours to cure before the system should be pressurized. The launcher will be under high pressure, and failure to allow adequate time for the joints to set may compromise the system.
Launch Operation
1) Fill the 2-liter bottle with water until it is between 1/2 and 2/3 full.
2) Turn the bottle over fitting it onto the riser. The bottle should have a firm seal on the riser, but it should not be on too tight.
3) Have people and pets back away 10 or more feet from the launch area.
4) Attach a tire pump with a built-in pressure gauge to the launcher's valve stem, then pump air into the launch system. DO NOT EXCEED 100 PSI IN THE SYSTEM. If the launcher reaches 100 PSI without launching the bottle, remove the pump and depress the valve stem pin to relieve the pressure. Once the system is depressurized, start over by not attaching the bottle as tightly.
5) When the pressure in the bottle is sufficient to overcome the friction of the seal, the bottle will blast from the launcher. Bottles can reach altitudes over 100 feet.
Safety Considerations
Use only with adult supervision.
Never exceed 100 PSI in the launch system.
Do not allow any part of the body over the 2-liter bottle while the launch is under pressure. Serious injury can occur if the bottle is launched into a body part.
Keep people and pets at a safe distance.
Use only undamaged pop bottles. Bottles with kinks or creases may rupture under pressure.
Fins or a nose cone may be attached, but do so using tape or general purpose glues (Elmer's®). Some adhesives like Liquid Nails®, Krazy Glue®, and hot glue can weaken the plastic of the soda pop bottle leading to a rupture under high pressure.