A few months ago I posted information on how to make a pop gun. In that post I mentioned the closely related sound of suction pops, as in the sound of a cork pulled from a bottle. Pop gun pops and suction pops both are very cool and quirky sounds, but suction pops have one advantage: unlike with pop gun pops, the pitch is predictable. If you wish, you can make suction poppers tuned to particular notes.
In this post I’ll describe how to make suction poppers. Suction poppers and pop guns are quite similar in design, and you can use most of the same components to make either. If you happened to read the earlier pop-gun post, and especially if you made a pop gun, then most of the suction popper making procedure will be familiar to you.
Here’s a sketch showing the essentials of a suction popper.
To make the suction popper, start with the main tube. Plastic tubing, such as PVC conduit, is suitable, and it’s widely available and inexpensive at hardware stores. Other sorts of tubing can work as well. ¾” diameter or thereabouts is good, if only because it’s easy to find corks to fit. The length of this tube determines the popping pitch. I have made successful suction poppers in lengths ranging from about 10 inches for high pitches to a several feet for low pitches.*
The two corks should have the truncated cone shape, as shown. The narrow end should be narrow enough to go inside in the tube; the wide end too wide to fit. This type of cork can often be found in hobby or crafts stores, if you don’t have any already around.
The plunger cork must be cut to fit the inside of the tube snugly. To get a perfect fit, shove the cork into the tube as far as it can go without forcing it. Cut off the end that’s still sticking out, and sand the cut end flush with the tube end. This gives you your fitted cork; pop it back out by pushing from the inside with a dowel coming through the tube from the opposite end.
For the plunger stick, you can use any sort of dowel or stick fits inside the tube, about ten inches long. Use a nail or screw to attach the fitted plunger cork to one and as shown in the drawing. Pre-drill the cork to prevent splitting before putting the nail or screw through it, and if the nail or screw doesn’t have a large enough head, include a washer.
That’s it; the suction popper is now ready to play. Insert the plunger in one end of the tube, place the stopper cork on the opposite end, and pull the plunger back out with a rapid motion. If you’re ambitious, make more suction poppers in graduated lengths to create a scale. Gather a group of friends to play suction pop compositions and improvisations in hocketing style.
*With longer tube lengths/lower notes, an unexpected effect comes into play: a prominent snap sound appears in the tone. I don’t know what causes this. You can hear the effect quite prominently in the sound sample on this page. The snapping on the low notes comes across almost like a distortion in the recording, but it’s actually part of the natural sound.