This is a bowl cast from concrete, utilising glass fragments from one of the infamous ‘smash and grabs’. I am not sure if this is an international term, of if it is mostly understood in my hometown Johannesburg and the rest of South Africa. I have featured this on my website, but I know that Instructables reaches a lot more people/ inventors/ magicians.
If you’ve grown up in Jozi (Johannesburg), you have more than likely seen the extra large glitter sprinkled messily beside your car. If not you, then someone you know. This sadly is not glitter. Rather, it is the cookie crumb trail left by the izinyoka (the snake) to whom you have just donated your car radio/speakers/ anything forgotten on your car seat. This happened one evening to a car parked outside my house. Lurking in the darkness with a dustpan and plastic packet, I collected all the glass fragments as I knew there may be a possible use for them in the future. These remained in a tub on my shelf for many months until I decided to use them as aggregate in a cast concrete bowl. It was a couple months after I made the badass concrete rocket, in which rubber fragments were used as aggregate.
The contrast of the matt, porous concrete and the sharp smooth greenish glass fragments create an interesting visual appeal. This however does not translate into an easily usable product for storing household items... The concrete grit will scratch your phone, or get transported on an apple and end up chipping your teeth.
Even though there are many sharp corners, they get enveloped by the concrete and create a relatively soft form.
What I would like to do next, is use a much higher percentage of glass, which may allow some light to pass through solid concrete. I have seen this online, but it is much easier said than done as concrete is a very difficult medium to 'tame'.
If you’ve grown up in Jozi (Johannesburg), you have more than likely seen the extra large glitter sprinkled messily beside your car. If not you, then someone you know. This sadly is not glitter. Rather, it is the cookie crumb trail left by the izinyoka (the snake) to whom you have just donated your car radio/speakers/ anything forgotten on your car seat. This happened one evening to a car parked outside my house. Lurking in the darkness with a dustpan and plastic packet, I collected all the glass fragments as I knew there may be a possible use for them in the future. These remained in a tub on my shelf for many months until I decided to use them as aggregate in a cast concrete bowl. It was a couple months after I made the badass concrete rocket, in which rubber fragments were used as aggregate.
The contrast of the matt, porous concrete and the sharp smooth greenish glass fragments create an interesting visual appeal. This however does not translate into an easily usable product for storing household items... The concrete grit will scratch your phone, or get transported on an apple and end up chipping your teeth.
Even though there are many sharp corners, they get enveloped by the concrete and create a relatively soft form.
What I would like to do next, is use a much higher percentage of glass, which may allow some light to pass through solid concrete. I have seen this online, but it is much easier said than done as concrete is a very difficult medium to 'tame'.
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You may not be aware of this (the instructable author as well!)... So I won't give the initally 'unbelievable secret' away right here but I will give everyone a web site to the French Chemist that discovered this over thirty years ago and has great utility today...I dare say you could make a cup out of this and drop if from 250 feet and not break it... There is a lot on the web site and a book(s) you can buy to learn more about this and to make it yourself... I think that I am going to 'pour' my own house of it...in Granite.
http://www.geopolymer.org/
Here the U.S. Military is using it and there are a lot of great links in the below story too:
http://www.wired.com/dangerroom/2009/10/super-concrete-in-the-us-military-iran-and-the-pyramids/
Have fun!!!
Seriously, glass can show off its best with nice cracked edges. There is a special ice like gloss in the edges of a fracture. I like the way you did this more than if the glass was tumbled first. Small pieces of solid copper wire can add to the look as well.
Bowls and sinks like this are cast using big and smaller bowls, which I get from restaurant supply houses or more industrial sources, such as tank head makers. Or, Target!
You can't really sand concrete. You might do better to rub-in the surface with fine sand and cement mix (wear rubber gloves.)
what about using very old, dry bread or toast or crackers...then when the concrete is cured, you can wash out the core making bits and filled with the larger bits of glass that you have...mortar them in place. maybe use small silicon shapes cut our from material or like the cruciform shapes used as tile spacers...carefully push them through, once the concrete has set.
HTH
When I saw your design and read your comment about using bigger pieces of glass to allow light through, I thought of "See through concrete". I remembered a novel design where they mix clear plastic fibers in the concrete and mold it into bricks. I've included a link so you can see how neat the idea is. You could use a similar technique to make your bowls.
I would think you could take fishing line cut into short lengths maybe 1.5" to 2" mix it with the concrete - mold the bowl then sand the bowl with increasingly finer sand paper until the fibers a become transparent. Actually you could course sand the bowl to smooth out and expose the ends of the fiber then quickly "paint" the surface of the bowl with a torch. Melting the ends of the fiber, not burning them makes them more transparent.
Check this out. http://dornob.com/see-through-light-transmitting-concrete-material/
Since it sounds like you are a very frugal person who never waists anything - like we should all be. While searching for the see through concrete I stumbled on this very unique brick design that uses leaves and plastic - I thought it is ingenious - maybe its a material you could use? Keep up the good work, it is a very niece looking bowl!!
Novel concept for a green brick - interesting choice of material I thought:
http://dornob.com/old-red-goes-green-recycled-wall-brick-built-to-save-water/
Best regards,
- Phil
Ciao,
no sharp edges.