|
You must sign in to view this presentation.*
*By signing in and accessing the video, you agree to the terms and conditions of this site.
The nuts of galvanized fasteners are coated with a wax lubricant that contains a dye. Once installed, the fasteners have to be cleaned to remove the wax prior to painting. Cleaning is typically accomplished using a combination of solvents and hand tools. Questions are raised as to how much residual dye on the surface is acceptable for painting. AASHTO/NSBA “Steel Bridge Collaboration S 8.1-2014,” which is also published as SSPC-PA Guide 13, “Guide Specification for Application of Coating Systems with Zinc-Rich Primers to Steel Bridges,” requires the removal of “excessive dye” but indicates that residual staining on the surface should not be a problem. However, there is no definition as to how much staining can be tolerated. As a result, projects are being performed where Owners are requiring that all staining be removed, which is a costly, time-consuming effort, and one that may not be unnecessary. This paper presents the results of a study that is being undertaken is to compare the performance of coatings on fasteners with different amounts of residual staining remaining on the surface after cleaning.
|
