I need to replace a broken coping tile on the edge of our fibreglass pool and wanted to check suggestions for the best adhesive that will bond to the fibreglass. It's a 300 x 300 terracotta tile and fits over the fibreglass lip of the pool plus where it meets the concrete surround (approx 80% fibreglass then 20% concrete). There appears to have been a gritty grey/black adhesive layer applied previously. Any tips or suggestions would be greatly appreciated.