by thomas » Thu May 01, 2014 2:46 am
A post on the dsg forum reported good results with superglue, but I wouldn't chance ordinary pound-shop superglue. The poster there had used a Loctite cyanoacrylate formulation Loctite 495, specifically made for rubber and plastics and coincidentally usable too for potable (drinkable) water systems, piping joints and so on, so is likely to be durable in the presence of moisture/rainwater too, which more ordinary stuff might not necessarily be in the longer term.
Remember the golden rule, measure five times, cut twice, or something like that; an inexpensive (99p) mitre block in which the rubber can sit closely might be very useful if accurate rather than approximate 45 degree angles are your goal, I think on the HB rear, the angle at the bottom corners is slightly less than 90 degrees, I'm unsure about the Firenza, but think like the HB it'll be so slight as to be able to get away with it.
I've seven and a half metres of correct profile rubber to do front and back screens on my HB and bottle of the above glue but I'm dreading tackling this job and constantly finding other things to do instead, on top of that the headlining is so brittle and fragile around the back window pillars too, that it adds more terrors. I recall with tears in my eyes someone on here snapping up an HB headlining (condition unspecified) for £4 from another member on here, for their GT resto I thought, but subsequently having a new one made for the GT, which means they might still have that first one and might surrender it to my pleas, unless it was in less than ideal condition or unusable.
Good Luck. You might try tracking down the dsg post, in all probability the Firenza owner there is a member here too and can fill you in on the details, tips and the durability of such glued joints in service.