This instructable will show you how I made a Urethane 3 Part Mold that I later used to cast concrete.

Step 1: Materials

I"m going to split up the process into 2 steps.

Urethane Mold:

Casting Concrete:

<p>Nice! There was a very famous german comedian named Loriot. In Germany, he was as popular as, let&acute;s say Monty Python in the UK. One of his best sketches is about a toy nuclear power plant: </p><p><iframe allowfullscreen="" frameborder="0" height="281" src="//www.youtube.com/embed/y82HNA11oSg " width="500"></iframe></p><p><iframe allowfullscreen="" frameborder="0" height="281" src="//www.youtube.com/embed/9oOGK_TKnYM" width="500"></iframe></p><p>In the first part, the grandpa buys the building kit as a christmas gift, in the second part it is put together and explodes (as intended) :)</p>
<p>Buen&iacute;simo! Mucho trabajo que completamente vale la pena! Muy original!<br>(Disfrutaste bastante el proceso me imagino!)<br>Estar&iacute;a bueno agregarle <em>bajo relieve</em> el s&iacute;mbolo de Radioactivo, algo as&iacute; como la muestra que hice :D Saludos!</p>
<p>Muchas gracias por el saludo. Si, el simbolo quedaria muy bien!</p>
<p>Great instructable! I have never built anything with Urethane molds but I was wondering why not making the outside urethane mold all at once and then cut it in two pieces? </p>
<p>Love the idea, you cast it well! Couple questions: is the mold material soft enough you could cast it in one piece, with the tower upside down? Also, for those with lathe access, I wonder if it could be turned.. Either way, I'm going to make shot glasses that look like cooling towers, thank you for the inspiration! </p>
<p>I think the flare in the shape of the top lip would create sufficient undercut to prevent a single piece mould (I assume you mean having the outer mould shell and core as one piece). If you were happy to modify the shape of the design slightly so that the tower tapers uniformly from the base to the lip, you could make that work. It wouldn't quite be accurate compared to a real cooling tower, but it would make the moulding and casting process easier, and eliminate the mould line on the outer wall of the tower casting.</p>
<p>The mold is soft but I don't think it won't work with the current design if you make a single part mold. As dustbuster7000 mentions you might need to change the design a little bit so it doesn't have any undercuts.</p><p>YES, this is a shape that you can work on the lathe.It would be really cool if you can make this shape in aluminum!</p>
<p>Brilliant idea the rice. You just solved a problem I was thinking about of 2 or 3 days for a project of mine. </p>
<p>Thanks! I'm glad this helped!</p>
<p>Super Cool!</p><p>I can almost hear a crow squawking.</p>
<p>Thanks! ;)</p>
<p>Cute cooling tower. Any plans to do say, a containment vessel too for paper clips perhaps?</p>
<p>Thanks! I don't know what a containment vessel is. Can you send copy a photo here? It would be really cool to expand and make a product line.</p>
<p>Thanks for inspiring me!</p>
<p>very cool.</p>
<p>You should use it to pot plants... get it?</p>
<p>Great idea!</p>
<p>Excellent! </p>
<p>This is a cooling tower model. Not all Nuclear power plants have them, and they are used for other things then Nuclear power plants. The reactor is inside the dome shaped structure (containment building) and the generators are in the factory-looking building. The one I worked on was mostly underground, with only a couple of stories above ground.</p><p>But it is an interesting project.</p>
<p>OK! Thanks for the info!</p>
<p>You took the words right out of my mouth. ;)</p>
<p>Very nice. Thanks for sharing.</p>
<p>I love it! what do you think about 3d printing directly the mold?</p>
<p>Yes, that was my initial plan but after I designed the 3D printed molds I realized it was a quite expensive to print the molds. I made another instructable in which I made a 3d printed mold to cast hot chocolate.</p>

About This Instructable




Bio: Alejandro is an industrial designer who focuses on creating impact through his designs. He has a broad background having worked at a graphic design agency ... More »
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