A waterborne topcoat had been spray-applied to the underside of a factory-primed galvanized steel deck at an exterior, sheltered location of a shipment station. After nine months, extensive intercoat delamination failure occurred. The root cause of the poor intercoat adhesion was investigated by onsite inspections, review of project documents, and laboratory testing. Infrared spectroscopical analyses were additionally employed to characterize the factory-applied deck primer and to understand its role in the delamination failures. As part of the investigation, five different topcoat products were applied to samples of factory-primed decking. The coating adhesion of these trial specimens was measured and evaluated. The investigation ultimately revealed the use of a topcoat incompatible with the factory-applied deck primer. The results of the investigation were utilized to develop an approach for successful future painting of the factory-applied deck primer.

Subject
Test methods, Primers, Manufacturing, Top coats, Substrates, Solvents, Wax, Substrate surfaces, Coating adhesion, Mechanical failure, Contractors, Adhesion testing, Hydrocarbons
Keywords:
Failures, Delamination, Field Testing, Investigation, Laboratory Testing, Infrared Spectroscopy, Wax, Bond Inhibitor, Surface Energy, Surface Tension
© 2025 Association for Materials Protection and Performance (AMPP). All rights reserved. This work is protected by both domestic and international copyright laws. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise) without the prior written permission of AMPP. Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
2025
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.