Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
I was a bit puzzled as to how there could be a 'crease' in the filler, but on closer inspection I think its a bad edge to a repair patch. I still find it incredidble that someone would think this OK, given that paint quality is all in the preperation, and wonder what sort of blemish would have been showing through before the bubble came up.Anyhoo, after reading recommendations on here and other forums, I'm toying with the idea of using a specialist bike painter who has done candy before, rather than finding out the hard way whether my local chap is any good at it. Everyone thinks Andy Parnaby's jobs are the dog's danglies, and I don't mind paying a bit more to have it right the first time, especially after the fun and games I had trying to get a side panel done in candy blue green to a reasonable standard locally (3 different painters, the first of which was me, even then it wasn't perfect with dust in the laquer that had to be polished out). He seems to have moved to Wetherby since Ash and others used him in Tockwith, but I found a 2017 number and email for him on a Triumph triple forum. I still don't know how you would paint candy without a sample to match for shade, but hje should have a better idea than my local car body shop of what we are after.
I wouldn't trust an old unknown liner, if it leaks or lifts then it risks damaging your nice new paintwork. A small leak can produce blisters like the one you started with.I'd take the opportunity to remove it if possible and to braze any holes it may be sealing. I've had both petseal and POR15 liners fail, in my opinion they're a last resort to use only when necessary.