Casting concrete countertop for under-mounted sink

[AndersMalmgren]

Hi, has anyone done this? A bit worried about the edge being neat since it's clearly visible with an undermounted sink. We plan to cast the countertop 30mm thick, but make a recess for the sink where it's only 10mm thick to save space under the sink. Do you think there's a risk that the concrete won't flow over the entire mold at 10mm (It's kind of like a mold within the mold, you could say)

 

[Allmänobildad]

Use fine concrete of the normal hardening type and make sure to vibrate the concrete properly around the edges to minimize air bubbles, and it should probably go well. If it still isn't satisfactory, you can smooth the edges with concrete filler.

 

[AndersMalmgren]

Thank you for the answer, the sink we have chosen seems to require at least 20mm thickness, so there should not be any problem with getting the concrete to flow out to all places

http://www.ido.se/Media/732937c5-5a62-45f6-85ec-6cd02ac28239.pdf