Various coating testing procedures are available to the coating industry and are utilized for evaluating coatings under various conditions of exposure.(1,2) Certain tests are applied only in the laboratory while other tests are applied only in the field. To reduce test time required to obtain meaningful results, some of these tests can be accelerated by increasing the intensity of some controlling factor or factors utilized in the testing procedure. Examples of some of the factors that are modified are temperature, pH, electrical potential, closeness to the ocean, cold wall effect, condensing conditions, and ultraviolet dosage.

For simplification in identifying the most appropriate tests for specific conditions, the tests have been broken down into major categories. Each category is related to the specific property or properties of the coating being evaluated or determined by the test. A breakdown of the categories addressed in this paper are

  • corrosion resistance,

  • weather resistance, including chalking resistance and color/gloss retention,

  • adhesion, resistance to delamination and disbonding,

  • permeability, moisture vapor transmission/cold wall effects, etc.,

  • physical and mechanical properties of the coating, hardness, toughness, and peel resistance,

  • undercutting and underfilm corrosion resistance,

  • blistering, related to permeability and adhesion and to substrate cleanliness and soluble salts, and

  • miscellaneous/other coating test variables.

Several representative tests are reviewed with suggestions on test duration, number of specimen to be utilized, data interpretation, and items that may require special attention. In addition, a listing of some of the various other tests available to the coatings engineer is presented, with literature references, though they are not discussed.

Subject
Costs, Test methods, Water, Coatings, Spray coating, Mechanical failure, Salt spray corrosion testing, Corrosion resistance, Maintenance, Blistering, Chalking, Paints, Coating systems
Keywords:
ASTM, coding test methods, accelerated, laboratory and field
© 1992 Association for Materials Protection and Performance (AMPP). All rights reserved. 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).
1992
Association for Materials Protection and Performance (AMPP)
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