I need to mount an undermount copper sink to our new kitchen surface. The surface is 4cm oak, which will be varnished with 12 coats of marine lacquer to protect the oak from water.
What I want to achieve is to cut out a very precise hole for the sink (I should add the sink is rectangular with curved corners), such that the cut out wood can be reinserted as a lid over the sink for additional workspace.
Elsewhere I cut out some rougher holes for domino hobs with a jigsaw but found it nigh on impossible to maintain straight and vertical edges.
I guess a cut width of about 4 mm will be necessary.
What tool or technique can I use to achieve my goal?