Sunday, May 9, 2010

Concrete Patio Table (Part 1.2 Mold Making)

The mold forms completed and starting to fill in the taper for the base. The first layer is cheap foam. The square bottom is the 3" base and will taper to 1" to the outer edge.
I am using spray foam to create the taper. It gets sprayed, struck off, and then sanded smooth.

3 comments:

  1. I was hoping you might help me. I am trying to make a copper sculpture for my living room. Its a Labyrinth and its about 4 feet square. I pressed the 3" copper in the labyrinth design into foam. I made a 4 foot sq mold out of plywood and poured in my mix of equal parts cement/peet moss/perilite.
    then i flipped over my copper in the foam to let it sink in the mix about an inch. after about a week i took off the foam to reveal my master piece. I let it sit for another week admiring its beauty in the mold. When i unmolded it it crumpled. it was about 225lbs and crushed under the weight of having to hold the @50lbs of copper. How can i make the foundation lighter? Im looking at the above table and thinking if i poured concrete on it - it would break off. Any ideas?

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  2. A cement, peat moss, perlite mix is going to be very weak. Concrete, even weak concrete, could easily support your copper but is going to weigh more. I would suggest designing a stronger concrete mixture with a reduction in volume of the base to lighten things up.

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  3. The mold forms completed and starting to fill in the taper for the base. The first layer is cheap foam. The square bottom is the 3" base and will ... concretemoldsforms.blogspot.com

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