Solvent free phenalkamine modified epoxy resin curing agent HW-558 with outstanding anti-corrosion performance Epoxy hardener HW-558 is phenalkamine modified epoxy resin curing agent with unique performance, suitable for solvent-free or high solid epoxy primer systems. The unique structure of cardanol modified phenalkamine gives the curing agent and its derived coatings unique properties. The curing agent has the advantages of fast curing, especially suitable for use under