[David Fitz-Henr]

Thanks Greg, that's interesting. I actually picked up a Sikaflex brochure from the local hardware a few days ago but haven't really considered it as I haven't seen anyone else use it for a mirror. Do you have any specific reason why you think it would be better? Looking at the TDS on the website, I see that Sikaflex 291 has similar properties to Selleys Glass Silicone, except that it has 5% shrinkage whereas Selleys Glass Silicone indicates no shrinkage. There is a Sikaflex 291I that has 2% shrinkage (although the site says this is for "experienced professional users only" ??).