I am trying to seal my old hot air heating/air conditioning ducts. I was told not to use the traditional duct tape, but to use special tape and mastic. My ducts are the flexible type, with a thin layer of insulation.
I found several kinds of metal tape at the HD. Are they all suitable for heating systems? The assistant did not have a clue.
I did not find any mastic at the HD. Any recommendation for the mastic and where to buy it?
Thanks