Water-based zinc-rich pre-construction primer

摘要

A water-based, two-part primer for metal substrates includes at least a first and second part, combined in a ratio of about 1 : 3. The first part of the primer may be substantially free of volatile organic compounds and include a colloidal silica present in the amount of about 20 weight percent to about (80) weight percent, based on the total weight of the first part; a silane coupling agent selected from the group consisting of epoxysilanes, mercaptosilanes, and modified silanes having a functional group active to an epoxy group, the silane coupling agent present in the amount of about 0,05 weight percent to about 15 weight percent based on the weight of the first part: and a cellulose ether in the amount of about 0.1 weight percent to about 2 weight percent. The second part may include from about 50% by weight zinc powder. The primer may be conventionally sprayable for use in large ship-building operations.