I have a sink to fit in a laminate worktop over a 1000 x 600 cabinet. Its a 1.5 bowl and drainer, total external dimension 1000 x 530 mm. The sink has a flat steel "designer" flange all around which includes the tap hole and is about 60mm wide along the front and back (only about 25mm around the sides). The fixing lugs are set 15mm in from the edge. The lugs take nylon/metal claw type clips that hook onto the lugs and tighten against the underside of the worktop.
Now, the obvious way to fit the sink is to form a single large cutout 974 x 504mm (4mm to allow tolerance and space for the metal clip to fit on the lugs). However next to the sink is a gap for a washing machine which leaves very little supported laminate along the edge of the sink.
So my general plan is now to cut out as little of the laminate as possible.
I'll do a main cutout for the bowls. Along the front and back with the large flange, I'll only cut where I need to (i.e. slots for the fixings lugs and clips, and a hole for the tap. This will also give a lot more sealant contact area and better support for the bowls. It will also help to constrain the fixing clips which have been known to slip off, I'm led to believe.
For the drainer, which has a depth of between 10mm and 20mm, I'll just route out as much depth of the worktop as required to allow clearance. Since the drainer is on the washing machine side, this will provide a lot more solid material where it is needed, and make the metal "ring" less with water dropping onto it.
The only flaw in all this is that there will be a lot more surface area of naked chipboard to get wet if the sealant around the edge were to fail. I plan to waterproof this with plenty of varnish / oil-based paint etc.
Question: Is all this trouble worth it, or should I just cut the big hole and have the thing only supported on 15mm all around the edge ?
At the very least, I think I'll need to avoid cutting right through under part of the drainer to give more solidity next to the washing machine.