Exploding Watermelons

7607-watermelon.jpgI love Halloween. One of my favorite activities is to “carve” pumpkins using a simple reation inside the fruit. First, you carve the face then carefully replace pieces. After creating a reaction by generating a gas inside and igniting it (ask your local chemistry teacher for the details) the face pieces are blown off with a small explosion.

Halloween is more than 100 days away and I just couldn’t wait. So I initiated the new weather anchor at the local Denver television station by introducing her to carving watermelons. The problem was, we didn’t really carve the watermelon, it exploded. Watch the Video to see how we skipped right over the carving and went straight to exploding.

35 replies
  1. carolyn ordal
    carolyn ordal says:

    I teach high school drop-outs/disenfranchised students in GED subjects. I would like to do the exploding watermelon experiment, but am not a science teacher (social studies major). How do you generate the gas to cause the explosion? Appreciate your assistance.

  2. Steve
    Steve says:

    The best advice is to pay a visit to your favorite chemistry teacher and ask her to do the Exploding Pumpkin/Watermelon demo for your students. The gas you’re generating is a small amount of acetylene. Your chemistry teacher probably has the write-up from Flinn Scientific.

    • Jeff O’Shields
      Jeff O’Shields says:

      I LOVE combustion demos using calcium carbide! I just did the self-carving watermelon demo for my students . . . They love it!!! You can see our demos on Instagram @mroshields (#selfcarvingwatermelon).

  3. Renita Ema
    Renita Ema says:

    Hello Steve, I teach chemistry at Laboratory primary school state university of Malang for grade 7 and 8. My country is Indonesia. I so interest with your experiment about exploding watermelon. This experiment can give me more information about chemical reaction surrounding us. I will tray to do this experiment with my student. Tanks steve…

  4. Amanda Macdonald
    Amanda Macdonald says:

    Hi Steve,

    I teach chemistry and would love to do this demonstration the first day of school. I tried to search Flinn to find the write up, but was unsuccessful. Can you point me in the right direction?

    Thank you for all that you do!


  5. Leyton
    Leyton says:

    hi steve i would like to know is the exploding water mellon chemical change? and also can you please send me instructions for making the exploding watermellon
    thanks leyton
    PS can you please send it to my email thanks;)

  6. Destynee boyle
    Destynee boyle says:

    hi my name is destynee and i want to do this for my science fair project and i would want to know how you get to do this it looks cool and funa nd i will have a parent gardian watching me do thiss project and help me do it i like to make stuf blow up catch on fire and so forth and i would love for you to email me the directions to this project
    thank you,,

  7. Julie Gintzler
    Julie Gintzler says:

    Hi Destynee, I think it is so great you are so interested in science but I have to tell you that no matter how cool it looks to blow stuff up, it is really dangerous. You have to learn a lot about chemistry and gases before you can do a demonstration like exploding watermelons. I hope you study chemistry when you get to high school and then you can do great demonstrations like exploding watermelons. Until then, you might enjoy looking at and trying some of the many experiments on the Steve Spangler Science website. Here is the link where you can find them: https://www.stevespanglerscience.com/experiments/

  8. Alyssa
    Alyssa says:

    Dear Steve,

    Im very intrested in this project and would like to use i for science class. I asked my Chemistry teacher and she does not know the “Secret”. If you could please send me the procedures, materials and some possible places where I might recieve the materials. If you could send it to my E-Mail, It would be greatly appreciated!! Thank you so much!!!

  9. Julie Gintzler
    Julie Gintzler says:

    If you search for “exploding watermelons” on our website, you’ll find a page that explains the reaction (in very general terms). As you know, we don’t put specific quantities on the website because we don’t want people to get hurt. I have to tell you that this is EXTREMELY dangerous. It is not our intent to be evasive, rather to protect the safety of those who use our site and are not trained in the usage of chemicals. The experiment starts with the carving of a watermelon and the build up of acetylene gas which is ignited. The truth is that there really is no exact recipe since each watermelon is different and there’s always the chance that too much acetylene gas built up in the watermelon will make the whole thing will explode! There is a set of chemical reference books called “Shakhasairi Chemical Demonstrations” series. This chemical text series is designed as a high level chemical demonstration text. You will find the full experiment details in these books.

  10. Danielle
    Danielle says:

    This project seems pretty awesome!!……. I am a student at G.E.M.S at seisd and all my friends would be intrested in this project!….Science class should have more stuff like this and my Partner Maria agrees stongly! (:

  11. Julie Gintzler
    Julie Gintzler says:

    Sorry Andrea – Although the exploding watermelon is an awesome demonstration to watch, it is a dangerous experiment and is not meant to be done by anyone who is not properly trained in the handling of combustable chemicals.

    • Susan Wells
      Susan Wells says:

      Hi Amber – this is a science demonstration presented for educational purposes. It is not a hands-on experiment. For safety reasons, we do not disclose the steps or ingredients for this demo. For more information, we suggest you ask your favorite chemistry teacher. They have all the cool answers!


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