drilling wet wall with standard hole saw?

[Glenbirnie]

I have nearly finished a new bathroom. Shower over bath with a sheet of white wet wall on the ceiling above so I dont have to repaint it every few years!

I need to drill a hole for a downlight, 70mm hole. I was planing using a standard Bosch hole saw for wood etc the type youll get in most builders merchants.

I am worried it chips the wet wall on the way through the white surface. Once through that then the plywood back will be fine.

Any tips or anything with a finer tooth pattern. Hole saws generally have an agressive tooth pattern.

I was going to put masking tape on the surface prior to drilling but im not convined that does a lot. Plan was also to use a high speed on the drill.

Thanks

 

[foxhole]

Only minor chipping which will be hidden by light fitting rim.