On Thursday, 25 January 2018 12:43:20 UTC, alan_m wrote:
I need to surface fix some plastic electrical trunking to a fairly
irregular surface internal wall. Would a grab adhesive be suitable for
this application or would I be better off drilling through the back and
attaching using screws?

Drill and screw, and if it's over an escape route you'll also need metal cable restraint clips inside the trunking.

Owain