First some background information - One of the materials I will be working with extensively is concrete, in all its various forms. Countertops, table tops, furniture, sculpture, all sorts of useful things that can be cast with concrete if you take the time to understand it. The material is quite amazing. It’s a proprietary mixture of cement, aggregate, sometimes other found objects like broken glass or molten aluminum etc., and very small strands of fiber to reinforce the mixture and cut down on the weight. Challenge is, when you pour concrete into a mold, in order to perfect the cast, you need to have some way to get the air out. As it turns out, if you vibrate the whole thing at the right frequency, the air simply bubbles to the top and exits. Hence the need for a really big, long table that floats on air and vibrates.
|The initial layout of 4 inch square tubing|
|Heavy mounts for casters|
|Final assembly of the frame|
|Air bags for lifting the table top|
|Pneumatic controls and air bags|
|Add one 1,200 lb industrial vibrator|
|The finished table|
To test the table I went ahead and cast a counter top for one of the vanities in my loft (guest bedroom). Here are some pictures of a small concrete top being cast in a 2-part mold.
|The final mold assembly before the pour|
|The first part of the pour. Notice the ripples from the vibration.|
|Adjusting the frequency to get the air out|
|Inserting the second half of the mold|
|The cast counter top, right out of the mold. The hole in the middle is designed to accommodate a shallow reveal for a new vessel sink I have in mind.|