You Can Put Toothpaste In The Tube (With Effort)

Old wives’ tales, folk knowledge, common sayings, and even cliches and idioms are often taken as givens since they form an often unnoticed part of our vocabulary and culture. There’s so many examples that it’s possible to fill a 17-season TV show busting potential myths like these, and even then there are some that slipped by. For example, the saying “you can’t put toothpaste back in the tube” which, as it turns out, is not as impossible as we might be led to believe.

This video is the product of [Tyler Bell] who has taken this idiom on as a challenge. To figure out if it was possible he first got to work building a vacuum chamber, which turned out to be a little easier than he thought it would be. After cutting a piece of polycarbonate tube and sanding it down, all that was needed were some rubber gaskets and fittings for the vacuum pump.

From there, the theory was to put an empty toothpaste tube into the vacuum chamber, pump all of the air out, and let atmospheric pressure “push” the toothpaste back into the tube. During [Tyler]’s first run he thought that it had worked successfully but it turned out that he had just inflated the empty toothpaste tube like a balloon. Further iterations were able to return some of the toothpaste to the tube, but each time some air would eventually work its way into the toothpaste which would immediately fill the remaining space in the tube with air rather than toothpaste.

While not completely successful, he was able to get some toothpaste back into the tube with a relatively small bill of materials. It’s not likely that this experiment will result in a change of this particular idiomatic expression, but it was interesting to put it to the test nonetheless. For other instances of toothpaste and its relationship to tubes, both inside and out, be sure to check out this recent piece on various methods of toothpaste storage.

Thanks to [Emiel] for the tip!

20 thoughts on “You Can Put Toothpaste In The Tube (With Effort)

      1. +1 I’ve re-filled small sample toothpaste tubes for travel & camping like this for years. Sometimes there is a little leakage around the mouths, but just use it to brush your teeth.

    1. I do this all the time. No need to fab anything, just unscrew two caps, glue them together back-to-back. I squeeze paste from a large tube into a small tube to comply with airport carry-on restrictions.

      1. I did this. Epoxy together, drill out the “tops”. I did it because my wife is a middle squeezer. When no more came out, she through it in the garbage. I convinced her to put those “empty” tubes in a box under the sink. Periodically, I would use the female/female connector, and squeeze from the end to push the paste into another “empty” tube. I typically got 1 full tube and 2 empty tubes. That is a lot of not wasted toothpaste. I guess she is one extreme, and I am the other: not only am I an end squeezer, but I have a bit of 3/4″ copper pipe I use to roll the tube from crimp to spout to remove as much as possible (including folding the tube’s spout end to push into the spout base).

  1. Called it.

    socksbot says:

    June 24, 2021 at 9:30 am

    And now we wait for the HaD post featuring a vacuum cylinder to make the tube suck the paste back in, like the artificial lungs of old.

  2. Because opening the other end and filling it as it’s done in the factory, then trying to reseal it, is too easy. I still say metal tubes were easier to refill, they weren’t sealed as such, but merely folded over tightly a few times. Not many companies use metal tubes these days it seems.

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