When cutting hole

[paradox]

Ok well i am gonna be putting a 120 mm hole in my project case and i was wondering should i cut the hole before or after putting the filler in?

From what i have heard and read i should put the filler in first then after cut the hole and sand it. But how do you guys do this? Thanks.

[mnpctech]

Can you be more specific about youre trying to do paradox?

You will crack any filler trying to run a holesaw though it.

[paradox]

Ok well here is the case that im working on...(attached). I need to fill the area so its pretty much rounded up to a hill kinda. The bottom of 120mm fan hole i want is gonna be right at the circular part of the black plastic under power switch.

So you think i should cut the hole first then just like keep it open and sand out whatever is in the way?

[Darv]

It would be easier to cut it first and then fill it. No problems of it cracking and you could probably shape it better after it's been cut.