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.
How to make a concrete countertop with integrated sink.
I had to make it my own with the sink and adding lights.
To polish the concrete countertop to a smooth finish use an abrasive pad and a water feed to smooth the sides and concave sinks.
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.
Make the sink mold concrete artist buddy rhodes uses fabric resin and body filler to build a mold for a stylish concrete vanity basin.
Concrete countertop with integrated sink and fiber optics.
Making a custom concrete countertop with an integral sink is an approachable project for anyone with decent carpentry skills and a willingness to learn.