Can anyone think of a way of crafting a simple model (melonbot from supertato) that would dissolve in a paddling pool after being used as a prop? Although it would be a bonus to put little pool toys in the model it's not essential.

Some ideas I've had so far

  • ice (would make the paddling too cold)

  • glue and paper (would make the pool too messy)

  • bath bomb (no idea how to make one that would be large and that would be safe to swim in after)

If anyone has any ideas or ways round the above problem it would be great!

Our plan is to have a supertato themed kids party where we read through the sports day book doing all the activities and finishing with melon bot 'crackling, sparking and exploding' in the paddling pool :)

For anyone who wants context :)

Link to the story: Supertato run veggies run - Books Alive! (YouTube).


Your question brings to mind a concept of water soluble paper. The Google tells me there is such a product, at least one or two, perhaps more.

The web sites indicate that it's often used to make easily transportable soap (for camping) or embedded in clear glycerin soap bars. The second link also notes that the paper is quite thin. The first link provides a video of the user applying liquid soap and lifting the paper from the surface, implying that it is not extremely fragile.

The second web site has pricing, US$0.75 per sheet, US$0.42 cents in hundred lots. That seems expensive, but that's just an opinion.

White glue will dissolve in water, especially the glue sticks and this paper dissolves in water. You may be able to construct the model in the manner you desire and allow for a vanishing melonbot in the pool!

Inflating a balloon to use as the form, leaving the knot outside, allowing the stuff to dry, then popping and removing the balloon should work. In the manner of Papier-mâché allows the use of cornstarch or flour, which should not make too much of a mess in the pool.

  • This looks brilliant and I never would have thought of it! I will look into pricing and see if I can do a little prototype :) Jul 15 '18 at 10:45

I wonder about a thin ice shell. That wouldn't be too cold, and could be coloured with food dye. You could use an overgrown version of the cocktail in ice ball method (though you might have to improvise your own mould) or something like (I haven't tried this but now want to):

  • fill a balloon with salt solution (something like 200g/litre and freeze.
  • dip the balloon in cold water, repeatedly, putting it back in the freezer in between if necessary
  • the tricky bit -- put it in a freezer that's well above the freezing point of the salt water inside but well below 0°C (32°F). This will melt the inside but not the outside.

You could also use (denatured/rubbing) alcohol for the freezing point depression if it's not going to be near food.

  • ooh i'm intrigued, that definitely gets round the making the pool to cold issue but i would worry it would be too fragile to use as a prop most of the day. But I really want to make a Ice pitcher or something now using this technique :) Jul 16 '18 at 8:45
  • 1
    @chrispepper1989 It would melt pretty fast at room temperature, I reckon.
    – Chris H
    Jul 16 '18 at 9:02
  • 1
    yer I agree, probably wont work in this case, but damn I want to try it anyway :) Jul 16 '18 at 10:37

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.