Recently, on multiple projects there have been requirements for The EC to provide exothermic cadweld of ground conductors to the re-bar however I know there are acceptable compression clamp methods, multiple EC's recently have mentioned issue with the ground conductor and cadweld "holding" after the cadweld process even after multiple attempts. Just curious on everyones thoughts and experiences this is there any type of prep of the rebar that need to take place in order for the cadweld to hold better to the re-bar?