Just to remind you, if anyones from Peterboro' then i'm at CTD in the morning, i'll also have the new 2.5mm CT (which refers to the gap that you want to fill and gives a 3.5mm bead of silicone) and i'll show you how to get such a fine joint without getting into a mess no matter how good or bad you are with a silicone gun.
Best regards
Andy