We painted a 30' dia. x 110' tank. The exterior we used a enclosed spider called and "E tank". With a high capacity hepa vac. The E tank saved the cost of enclosing the structure with staging and tarps. We attempted at first to satge and tarp the structure but the wind ripped it to shreads. We...
I have used uniflages on prime painted and tar coated steel and ductile iron pipes with out issue. Flange coupling adaptors are a much better coupling and allow much more flex in the pipe.