Making a hole in Astra Cast sink unit

[stevelewis430]

How do I safely make a hole of around 32mm in my astra cast (acrylic, I think) sink unit?

I need to mount an air switch for a waste disposal unit.

Thanks in anticipation......

[Huge]

Carefully.

My plastic bath came without tap holes. I stuck masking tape over where the holes should be, measured and marked them about 3 or 4 times :o) then drilled small pilot holes (& measured again), then drilled the full size holes (IIRC, with a spade bit, run very, very slowly.)

[rbel]

I cut a hole for a filtered water tap in a Rok composite kitchen sink with one of these

and associated arbor they are not cheap but given the cost of the sink I thought it was worth it. The composite is extremely tough and it will take a while to get through it.