dolphinGB replied on 13/06/2019 11:53
Posted on 13/06/2019 11:53
In April 2016 I replaced a roof light which had been cracked by golf-ball sized hail. I decided to use 'the best' and after thoroughly cleaning the hole of old mastic, with white spirit, and drying and degreasing with methylated spirits, leaving it spotless. I also degreased the new pp rooflight. It was a dry warm day, and I installed the rooflight with Sikaflex 512, and expected to never have to touch it again.
Move on to June 2019, heavy rain in Scotland and there is water dripping from the rooflight. On unscrewing the inner edge, I simply pushed the window up and it came completely away easily, leaving the pp plastic rooflight upper frame edge spotless, but with a perfect reverse of the inside frame edge glued irremovably to the van roof. So at least it stuck to something!
Anyone else had this?, presumably due to the type of plastic being pp ( stamped on the inside edge of the frame) Sikaflex does not adhere to this?