<p>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 <a href="http://www.cocktailchemistrylab.com/home/ice-ball-cocktail" rel="nofollow noreferrer">cocktail in ice ball</a> method (though you might have to improvise  your own mould) or something like (I haven't tried this but now want to):</p>

<ul>
<li>fill a balloon with salt solution (something like <a href="https://commons.wikimedia.org/wiki/File:Saltwater_freezing_point.jpg" rel="nofollow noreferrer">200g/litre</a> and freeze.</li>
<li>dip the balloon in cold water, repeatedly, putting it back in the freezer in between if necessary</li>
<li>the tricky bit -- put it in a freezer that's well above the freezing point of the salt water inside but well below 0&deg;C (32&deg;F).  This will melt the inside but not the outside.</li>
</ul>

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

CC BY-SA 4.0
2018-07-16T08:45:13.047Z
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 :)
chrispepper1989
CC BY-SA 4.0
2018-07-16T09:02:03.983Z
@chrispepper1989 It would melt pretty fast at room temperature, I reckon.
Chris H
CC BY-SA 4.0
2018-07-16T10:37:21.300Z
yer I agree, probably wont work in this case, but damn I want to try it anyway :)
chrispepper1989
CC BY-SA 4.0
2018-07-16T08:38:42.570Z
2018-07-16T08:38:42.570Z
Chris H
<p>Your question brings to mind a concept of water soluble paper. The Google tells me there is such a product, <a href="https://www.smartsolve.com/water-soluble-paper/" rel="nofollow noreferrer">at least one</a> or <a href="https://www.brambleberry.com/water-soluble-paper-p3318.aspx" rel="nofollow noreferrer">two</a>, perhaps more.</p>

<p>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.</p>

<p>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.</p>

<p>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!</p>

<p>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 <a href="https://en.wikipedia.org/wiki/Papier-m%C3%A2ch%C3%A9" rel="nofollow noreferrer">Papier-mâché</a> allows the use of cornstarch or flour, which should not make too much of a mess in the pool.</p>

CC BY-SA 4.0
2018-07-15T10:45:08.170Z
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 :)
chrispepper1989
CC BY-SA 4.0
2018-07-14T23:47:13.520Z
2018-07-14T23:47:13.520Z
fred_dot_u
<p>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. </p>

<p>Some ideas I've had so far</p>

<ul>
<li><p>ice (would make the paddling too cold)</p></li>
<li><p>glue and paper (would make the pool too messy)</p></li>
<li><p>bath bomb (no idea how to make one that would be large and that would be safe to swim in after)</p></li>
</ul>

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

<p>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 :)</p>

<p>For anyone who wants context :)</p>

<p>Link to the story: <a href="https://youtu.be/QYDLjX6PWA0" rel="nofollow noreferrer">Supertato run veggies run - Books Alive!</a> (YouTube).</p>

<material-selection><material-identification>
Dissolvable Piñata?
chrispepper1989
# Dissolvable Piñata?

(Asked by: username_0 on 2018-07-14)

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!](https://youtu.be/QYDLjX6PWA0) (YouTube).

**Tags:** material-selection, material-identification


---

## 2 answers

### Answer by username_2 on 2018-07-14. Score: 4 | Accepted answer

Your question brings to mind a concept of water soluble paper. The Google tells me there is such a product, [at least one](https://www.smartsolve.com/water-soluble-paper/) or [two](https://www.brambleberry.com/water-soluble-paper-p3318.aspx), 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](https://en.wikipedia.org/wiki/Papier-m%C3%A2ch%C3%A9) allows the use of cornstarch or flour, which should not make too much of a mess in the pool.

> **Comments:**
> **username_0**: 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 :)  

---

### Answer by username_1 on 2018-07-16. Score: 2

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](http://www.cocktailchemistrylab.com/home/ice-ball-cocktail) 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](https://commons.wikimedia.org/wiki/File:Saltwater_freezing_point.jpg) 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.

> **Comments:**
> **username_0**: 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 :)  
> **username_1**: @username_0 It would melt pretty fast at room temperature, I reckon.  
> **username_0**: yer I agree, probably wont work in this case, but damn I want to try it anyway :)  

---

