Finings are not necessary (that'll please Janx that I said that....note I said "necessary").
Finings, Irish Moss, and Polyclar are things we can use to help us clear our beer. All of these are used at differnet times in the process.
Since you are in the secondary and are conditioing around 18-19 C then this time alone will allow your beer to clear up. If you want there is still time to add Polyclar to your beer. Polyclar is powdered PVC (my understanding of it) so you do not want all of the beer from the secondary when racking to the bottling bucket. Leave it undisturbed and behind.
Ok, thanks for the help.
I have now added a packet of liquid finings to the keg and it is now sitting at 19 degrees. Is there any tell tales to show me when it is ready or do I just try a bit in a couple of weeks (it has already built up enough pressure for the tap to work)
I am intending to bottle in grolsh type flip top bottles do I just attach a hose to the tap and pour it into the bottles (keeping the end of the tube below the beer in the bottle)? do I add any further sugar (as the keg was primed with 4 oz before the beer went in?