In the process of overhauling the oil boiler's balanced flue outlet.
The circular 100mm dia exhaust flue coming out of the boiler sleeves into another which goes through the wall. The joint was originally bound and sealed with a Duck Tape like tape.
The boiler is 1999 vintage, but I can't recall where I obtained the tape - it may have come with the flue kit.
Presumably it is a special heat resistant type, so normal duct tape won't do. Anyone know what the tape is called, please? A pointer to a source would be helpful.
TIA