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6 Coating of Steel Structures Hydroblasting and Coating of Steel Structures H yd rob I ast i ng and Coating of Steel Structures Andreas W. Momber Privatdozent, Department of Mining, Metallurgy and Earth Sciences, RWTH Aachen Germany ELSEVIER UK USA JAPAN Elsevier Ltd, The Boulevard, Langford Lane, Kidlington, Oxford OX5 lGB, UK Elsevier Inc, 360 Park Avenue South, New York, NY 10010-1710, USA Elsevier Japan, Tsunashima Building Annex, 3-20-1 2 Yushima, Bunkyo-ku, Tokyo 1 13, Japan Copyright 0 2003 Elsevier Science Ltd. 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, electrostatic, magnetic tape, mechanical, photocopying, recording or otherwise, without permission in writing 6-om the publishers. Cover illustration: Courtesy of Muhlhan Surface Protection International GmbH, Hamburg, Germany British Library Cataloguing in Publication Data Momber, Andreas W., 1959- Hydroblasting and coating of steel structures 1.Water jet cutting 2.Stee1, Structural - Cleaning 3.Building, Iron and steel - Cleaning 1.Title 620.1’06 ISBN 185617395X Library of Congress Cataloging-in-Publication Data Momber, Andreas W., 19 59 - Hydroblasting and coating of steel structures / Andreas W. Momber Includes bibliographical references and index. ISBN 1-85617-395-X (hardcover) p. cm. 1. Steel, Structural - Corrosion. 2. Corrosion and anti-corrosives. I. Title. TA467 .M545 2002 620.1’723 -dc2 1 2002040768 No responsibility is assumed by the Publisher for any injury andlor damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. Published by Elsevier Advanced Technology, The Boulevard, Langford Lane, Kidlington, Oxford OX5 lGB, UK Tel: +44(0) 1865 843000 Fax: +44(0) 1865 843971 Typeset by Newgen Imaging Systems (P) Ltd, Chennai, India Printed and bound in Great Britain by Biddles Ltd, Guildford and King’s Lynn Contents List of Symbols and Abbreviations Used 1 Introduction 1.1 Definitions of surfaces and preparation methods 1.2 Importance of surface preparation processes 1.3 Subdivision of water jets 1.4 Industrial applications 2 Fundamentals of Hydroblasting 2.1 Properties and structure of high-speed water jets 2.2 Basic processes of water drop impact 2.3 Parameter influence on the coating removal 2.4 Models of coating removal processes 3 Hydroblasting Equipment 3. I 3.2 Pressure generator 3.3 High-pressure hoses and fittings 3.4 Hydroblasting tools 3.5 Nozzle carriers 3.6 Hydroblasting nozzles 3.7 Vacuuming and water treatment systems High-pressure water jet machines 4 Steel Surface Preparation by Hydroblasting 4.1 Efficiency of hydroblasting 4.2 Cost aspects 4.3 Problems of disposal 4.4 Safety features of hydroblasting 5 Surface Quality Aspects 5.1 Surface quality features 5.2 Adhesion strength 5.3 Flash rust 5.4 Non-visible contaminants - salt content vii 17 18 24 29 38 45 46 47 55 59 63 66 73 77 78 84 87 94 113 114 114 121 126 vi Contents 5.5 Embedded abrasive particles 5.6 Wettability of steel substrates 5.7 Roughness and profile of substrates 5.8 Aspects of substrate surface integrity 6 Hydroblasting Standards 6.1 Introduction 6.2 Initial conditions 6.3 6.4 Non-visible surface cleanliness definitions 6.5 Flash rusted surface definitions 6.6 Special advice Visual surface preparation definitions and cleaning degrees 7 Alternative Developments in Hydroblasting 7.1 Pulsed liquid jets for surface preparation 7.2 Hydro-abrasive jets for surface preparation 7.3 High-speed ice jets for surface preparation 7.4 Water jethltrasonic device for surface preparation References 133 136 138 144 149 150 151 152 154 155 157 159 160 169 176 181 183 Appendix 199 Index 203 ~ ~ List of Symbols and Abbreviations Used model parameter jet structure parameter cleaned surface cleaning rate nozzle (orifice) cross section plunger cross section jet structure parameter fatigue parameter cleaning energy flux speed of sound water constant speed of sound target paint consumption jet spreading coefficient paint degradation rate drop diameter maximum drop diameter Sauter diameter (water drop) dry film thickness hose diameter jet diameter nozzle (orifice) diameter plunger diameter threshold nozzle diameter cleaning effectiveness kinetic energy hydro-abrasive jet cleaning efficiency kinetic energy water jet Young’s modulus kinetic energy abrasive particle specific energy frequency pulsating liquid jet [...]... construction engineering applications of water jets 13 14 Hydroblastingand Coating of Steel Structures jet cutting of construction materials, such as tiles, natural rocks and glass (Momber and Kovacevic, 1998); removal of asphalt and bitumen from road constructions (Momber, 1993b); removal of rubber deposits from airport runways (Choo and Teck, 1990); removal of traffic marks from roadways; selective... cleaning: removal of deposits (Lenz and Wielenberg, 1998); ship cleaning in the maritime industry: removal of marine growth, loosen paint, dirt and rust; sieve and filter cleaning in the process engineering industry: removal of production leftovers, especially solidified agglomerates (Jung and Drucks, 19 96) ; steel cleaning in steel mills: removal of weld slag, water scale, mill scale and rust (Raudensky... include the following: a a a a a cleaning of concrete joints prior to concreting (Utsumiet aL, 1999); cleaning of concrete, stone, masonry and brick surfaces (Lee et aL, 1999); cleaning of soils (Sondermann, 1998); cutting and drilling of natural rocks in quarries (Ciccu and Bortolussi, 1998); decontamination of industrial floors: 12 Hydroblasting and Coating of Steel Structures (a) Aircraft cleaning... be used for firmly adhering rust Residuals of dust and loose deposits will have to be removed 4 Hydroblasting and Coating of Steel Structures Table 1.1 Continued ~~ Procedure Remarks’ Water blast-cleaning Matter to be removed For removal of loose rust The surface profile of the steel is not affected For localised removal of rust Spot blast-cleaning Paint coatings Stripping Dry abrasive blast-cleaning... Nozzle Diameter Influence 2.3.4 Stand-off Distance Influence 2.3.5 Traverse Rate Influence 2.3 .6 Impact Angle Influence 2.4 Models of Coating Removal Processes 2.4.1 Drop Impact Model 2.4.2 Water Jet Cleaning Models 18 Hydroblasting and Coating 0 1Steel Structures 2.1 Properties and Structure of High-speed Water Jets 2.1.1 Velocity of High-speed Water Jets The properties of water are listed in Table 2.1... 1.1 Definitions of Surfaces and Preparation Methods 1.2 Importance of Surface Preparation Processes 1.3 Subdivision of Water Jets 1.3.1 Definitions and Pressure Ranges 1.3.2 Fluid Medium and Loading Regime 1.4 Industrial Applications 1.4.1 General Statement 1.4.2 Industrial Cleaning 1.4.3 Civil and Construction Engineering 1.4.4 Environmental Engineering 2 Hydroblasting and Coating of Steel Structures... blast-cleaning 1.2 Importance of Surface Preparation Processes IS0 8 502 states the following: ‘The performance of protective coatings of paint and related products applied to steel is significantly affected by the state of the steel surface immediately prior to painting The principal factors influencing this performance are: 0 0 0 the presence of rust and mill scale: the presence of surface contaminants,... decommissioning of nuclear power equipment (Lelaidierand Spitz, 1978; Bond and Makai, 19 96) ; decontamination of soils (Heimhardt, 1998; Sondermann, 1998); demolition of mercury-contaminated constructions; dismantling of nuclear power plants (Alba et al., 1999); encapsulation of contaminated ground and hazardous waste sites (Carter, 1998); removal of explosives from shells (Fosseyet al., 1997); removal of propellants... consist of automatically blastcleaned steel to which a prefabrication primer has been applied automatically in a plant Other painted surfaces Other painted surfaces consist of steel/ metal-coated steel which has already been painted Local demands Protectivecoating system Figure I 1 Evaluation process for a protective coating system (Pietsch and Kaisel: 2002) Introduction 3 Definitions and subdivisions of. .. classification: rustgrade: paint type 6 HydrobJasting and Coating of Steel Structures A first approximation of paint degradation rate is obtained using the following equation: The performance life of a coating system in years for a given environment for a designated rust grade of RG = 4.5, can be calculated using the following approach: Both equations are rather complex in structure and certain classified information . 6 Coating of Steel Structures Hydroblasting and Coating of Steel Structures H yd rob I ast i ng and Coating of Steel Structures Andreas. 1.Title 62 0.1’ 06 ISBN 18 561 7395X Library of Congress Cataloging-in-Publication Data Momber, Andreas W., 19 59 - Hydroblasting and coating of steel structures