Do we use primer and tanking liquid over the shower liner or just over the joints.
The tray doesn't need to be primed. In addition to that, primer is sometimes completely optional. Primer should be used to strengthen the walls and increase it's absorption.
You should apply the primer on the floor and walls, prior to fitting the tray. It should be left until it's dry.
Then you fix the tray to the floor with adhesive, waterproof it and all the surrounding, then proceed to tiling.
In case of any questions I will be happy to help.
David 020 7193 0953