One of Firovac's exclusive features is a special interior coating trademarked Firokote which protects the aluminum from corrostion. Also used are two (2) nine pound anode bars for electrolysis to work on.
The top pictures show white (aluminum) corrosion on uncoated aluminum tanks.
The bottom picture shows a 16 year old Firovac coated aluminum tank.
IMITATED BUT NOT DUPLICATED