Inhibition of cut edge corrosion of coil-coated architectural cladding

This study has investigated the solubility of inhibiting pigments and also the leaching behaviour of corrosion inhibitors from a polyester binder in a n acid rain solution. This study has relevance to the control of cut-edge c orrosion by inhibitor pigments, which are incorporated into the primer coat ings of coil-coated architectural cladding. The concentrations of leachate solutions in tubes glued to the top surface of primer-coated galvanised ste el specimens were measured using inductively coupled plasma emission spectr oscopy (ICPES) for a range of commercial inhibitors. In addition, the satur ated solubility was measured using ICPES. It was found that the leaching ra te, rather than the saturated solubility, controls the amount of inhibitor which is available for corrosion control at cut edges and in a coating defe ct area. These results are compared to impedance testing of polyester-coate d galvanised steel specimens coated with the same primers. (C) 1999 Elsevie r Science S.A. All rights reserved.