Repair vs. Replace: A Look at Rust
Determining how costly a rusty coating system will be to repair or replace is the focus of a new how-to video that breaks down corrosion distribution.
"Corrosion Assessment" is the newest addition to the instructional PaintSquare Video Learning Center series, which delves into multiple aspects of protective coatings work.
Created and narrated by experts at KTA-Tator Inc., the Video Learning series covers a wide range of topics in protective coatings work, from quality-control and health and safety issues, to basics on the proper use of coatings instruments.
From Lead Detection to Ventilation
Previous titles in the series include:
The series of short video segments includes "Destructive Testing of Paint and Coatings for Dry Film Thickness."
Future topics in the series include adhesion, holiday detection, steel surfaces and moisture testing.
Each installment is available free in the PaintSquare Video Learning Center.
In this video (2:52), KTA's William Corbett discusses how the amount of rust beneath or through a coating system is a significant factor in determining whether to repair or replace a coating system, or if substrate repairs are required.
"If corrosion spreads too far, repairs are very costly to perform ... It is best to perform repairs before the corrosion becomes too widespread," Corbett explains.
The video defines three distributions of rust: spot, general and pinpoint rusting.
"In order to make appropriate maintenance painting decisions, the amount and distribution of corrosion needs to be determined," Corbett says.
"If corrosion spreads too far, repairs are very costly to perform," Corbett warns.
However, estimating the percentage of corrosion can be challenging, so there is a standard that provides uniform means to determine amount and distribution of corrosion on the surface.
ASTM D610, Standard Test Method for Evaluating Degree of Rusting on Painted Steel Surfaces, works in conjunction with SSPC-VIS 2 to evaluate rust grade with a combination of visual examples with written specifications.