I am currently designing a 4 layer board using layer 2 as GND and layer 3 as
VCC. Everything has come together well, but I need to isolate an area around
some connectors and Relays which will carry 240VAC.
How do I manipulate the default polygon on these layers which appears to
cover the entire board layer to the edges. (also not considered good
practice as a 1-2mm gap to the board edge is recommended to prevent short
circuits when the board is manufactured).