Intro: Concrete Casting :Part Two: Countertop Mix.
This is the TCC countertop premium mix , cast into a latex mold.
The detail is very good and the bubbles are rare.
In this case I used the mix straight from the bag , into the mixing pails and mixed by hand. I did not add any pigment.
It released very easily despite the undercuts and the fact that the concrete is hard.
These casts will do well in the outside weather.
The raw effect is much like limestone .
I also tried the same mix , which I shall show later as a ' what not to do ,' example , in a video. I added dry art pigment ( powder paint ) and the mix failed miserably. It changed the chemistry of the concrete. The next cast I shall do will be with high quality liquid pigment cream added to the wet mix .
All we need to watch for when casting this material is bubbles.
Work the mix ( with its water component ) slowly with the fingers as you would art plaster . It's a slow technique , working the fingers through the mix until a thick cream like consistency is felt. Let this stand for a while ( two minutes or so ) and then shake to release bubbles . I spent five minutes tapping around the bucket until the bubbles stopped appearing on the surface.
Then pour the mix into the mold and shake it gently. Tap aound the mother mold until the bubbles stop coming to the surface.
As each layer of bubbles appears on the top , wipe them away with a wet finger or trowel. And shake again. Eventually the bubbles stop forming.
A mechanical shaker can be made using a reciprocating saw or sander attached to the mother mold. In that case the mother mold must be strong enough to handle the vibration. The other method is to attach the vibrating tool to a board on which the mold and mother mold are standing , filled with concrete. The bubbles come faster this way . But it's extra work and if you only do three a day or so , then it's not worth the bother.
Step 1: An Unedited Video of the Countertop Mix Casting.
The unedited video above shows the pull and the condition of the cast.