Making udev ignore certain devices during boot

I just wanted to post the solution to this problem, in-case somebody else is faced with a similar challenge.

Adding the following rules file did the trick:

/etc/udev/rules.d/90-hide-partitions.rules

KERNEL=="sda2",ENV{UDISKS_PRESENTATION_HIDE}="1" 
KERNEL=="sda3",ENV{UDISKS_PRESENTATION_HIDE}="1"