Using a sink mold sold here you can place the mold as part of your form work and pour the sink as part of the countertop this is a great option for overall strength of the concrete.
How to build a concrete sink form.
Make sure that none of the steel touches the edge of the form as this will show through in the finished vanity.
The box is 2 wider than the sink mold on all sides and sloped in the front to follow the slope of the.
Molded edges can be rough like broken stone or smooth and rounded.
Next set the steel in the half filled form.
Concrete countertop molds are made by a variety of countertop mold manufacturers each offering a unique benefit.
If so the form you build must include cutouts for the sink itself and if necessary for a faucet.
Set the expanded lath first and then the steel mesh on top of it.
Making a large hole as in the above 2 sink options greatly increases the overall weakness of the concrete piece and stress cracks are common around sinks.
Because the soupy concrete would simply run down the sides of the sink molds without them add a second tier to the form by building a pair of melamine containment boxes around the sink molds.
Once the second form is built it sits on top of the first form.
Most countertop experts shy away from integral concrete sinks as a primary kitchen sink.
To leave room for these fixtures you can build recesses into the form as in the picture above.
Attach these to the base form with wood braces and screws.
I m building this second part of the form separate from the base to prevent excess debris falling into the pour area.
Next build the second part of the form on top of this base.
How to build a gfrc concrete sink.
After lots of research online this is the process i came up with including.
The exception to this is the edges which often are made with a molded edge form available from a variety of sources or make your own rubber edge forms.
The other option is to simply use a knockout mold to create an opening for a stainless steel or porcelain sink.