After seeing pro’s making sand castles and learning about the Pound-up process. I thought it would be good to use the same process to cast my concrete product. I stumbled across a picture of a guy using a vinyl sheet to build sand up vertically. I have never found that image again. And I cant find anything else on the net where they use this vinyl sheet. Although you can’t make any undercuts… I think it’s still the best way to achieve complex curves with concrete. Because it’s a liquid, you’re normally limited to the shape of your mould because of gravity. So why not turn the mould on its side and pour it in from the top. The rebar can still be placed in the centre of the mould. Once the concrete dries you can remove the mould and flip the finished product on its feet.
I had some plaster of paris and some aluminium left over from my previous models. I couldn’t help myself. I had to try it out.
This shape comes from a clay model I made a few weeks ago- the shape was modified by a skater (see skate participant #1 blog post).
Note to self…Clay will not seal the bottom of the mould! Next time use gladwrap and sitcky tape.
Here is a clip I found on youtube that uses a flexible mould. Its interesting to see what is possible with a liquid material. Notice the foam-like flexilbe mould being used on a horizontal surface. Non-stick!