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Adhesives in marine engineering
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© Woodhead Publishing Limited, 2012
Adhesives in marine 
engineering
Edited by
Jan R. Weitzenböck
Oxford Cambridge Philadelphia New Delhi
© Woodhead Publishing Limited, 2012
Published by Woodhead Publishing Limited,
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First published 2012, Woodhead Publishing Limited
© Woodhead Publishing Limited, 2012; except Chapters 6 and 7 which are 
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ix
(* = main contact)
Editor and Chapters 1 
and 2
Dr Jan R. Weitzenböck
Det Norske Veritas AS
Veritasveien 1, 1363 Høvik
Norway
Email: Jan.Weitzenboeck@dnv.com
Chapter 3
Dr Holly J. Phillips
Royal National Lifeboat Institution
West Quay Road
Poole
Dorset
BH15 1HZ
United Kingdom
Email: hphillips@rnli.org.uk
Chapter 4
Dr Christof Nagel*, Andrea 
Sondag and Dr Markus Brede
Fraunhofer Institute for 
Manufacturing Technology and 
Advanced Materials IFAM – 
Adhesive Bonding Technology 
and Surfaces
Wiener Str. 12
D-28359 Bremen
Germany
Email: christof.nagel@ifam.
fraunhofer.de
Chapter 5
Dag McGeorge
Det Norske Veritas AS
Veritasveien 1, 1363 Høvik
Norway
Email: dag.mcgeorge@dnv.com
Chapters 6 and 7
Dr W. Broughton
Materials Processing and 
Performance
Materials Division
National Physical Laboratory
Hampton Road
Teddington
TW11 0LW
United Kingdom
Email: bill.broughton@npl.co.uk
Chapter 8
Dr J. Comyn
Department of Materials
Loughborough University
Loughborough
Leicestershire
LE11 3TU
United Kingdom
Email: comyn.john@yahoo.co.uk
Contributor contact details
© Woodhead Publishing Limited, 2012
xi
Preface
Adhesive bonding is an established joining method in the railway and 
automotive industry. In shipbuilding and offshore engineering, it has yet to 
gain the same broad acceptance. However, there are many benefi ts that 
make adhesive bonding very attractive. For example, in lightweight con-
struction one may join plates that are too thin to weld or material combina-
tions that cannot be welded. Furthermore, the lack of hotwork produces 
smooth surfaces, e.g. on superstructures, and also substantially reduces the 
risk of fi re or explosion during construction. Lack of experienceand lack 
of documented long-term performance are currently limiting the use of 
adhesive bonding.
This book aims to provide a rigorous treatment of the subject with focus 
on practical application and use and it is thus also aimed at the practising 
engineer, not just an academic audience. The book focuses on adhesively 
bonded joints that transfer loads and moments and have a structural func-
tion, and does not deal with adhesion of thin fi lms or sheets such as 
coatings.
The book addresses many important aspects for the successful applica-
tion of adhesive bonding in shipbuilding and offshore structures:
• Requirements for bonded connections and application examples in 
ships and offshore structures (Chapter 1)
• Selection of adhesives and predesign (Chapter 2)
• Design and fabrication of bonded joints for advanced ships (Chapter 3)
• Design of adhesively bonded joints for wind turbine blades (Chapter 4)
• Predicting failure of bonded joints (Chapter 5)
• Characterising adhesive properties by testing (Chapter 6)
• Assessing moisture resistance of bonded joints (Chapter 7)
• Assessing durability in wet conditions (Chapter 8)
The editor would like to take this opportunity to thank all the authors of 
the chapters for their time, dedication and patience. It is their collective 
© Woodhead Publishing Limited, 2012
xii Preface
effort that has made this book possible. We hope that this book will serve 
the needs of all those engaged in the design, fabrication, operation and 
repair of adhesively bonded joints for ships and offshore structures.
J. R. Weitzenböck
Det Norske Veritas AS
Norway
© Woodhead Publishing Limited, 2012
1
1
Introduction to using adhesives in marine and 
offshore engineering
J. R. W E I T Z E N B Ö C K, Det Norske Veritas AS, Norway
Abstract: The chapter provides a brief overview of the use of adhesives 
in marine and offshore engineering. Firstly, some basic terms for 
adhesive bonding are defi ned, followed by a general overview of future 
technology development that may infl uence the use of materials and 
joining methods such as adhesive bonding. Next, a state of the art study 
is presented on the actual and potential use of adhesives, based on the 
literature and the author’s personal experience, followed by a brief 
outline of the certifi cation and approval regimes for bonded structures. 
Finally, an outlook and references are presented for further information 
for the interested reader.
Key words: adhesive bonding, ship building, wind turbines, offshore 
engineering, design for adhesive bonding, international regulations.
1.1 Introduction
During the design, fabrication and modifi cation of ships and offshore struc-
tures there are innumerable joining tasks to assemble the structure and to 
install equipment. The vast majority will be done using welding and perhaps 
some other mechanical joining process such as bolting or riveting. However, 
there are situations where these joining processes are not the best option. 
Typically this is for the assembly of lightweight structures based on thin 
materials or material combinations such as composite and steel that cannot 
be welded. However, to be successful, adhesively bonded connections not 
only need to have suffi cient mechanical strength and long-term perfor-
mance, but they fi rst and foremost have to be economically viable.
What do we mean by ‘adhesive’? According to Adams et al. (1997), ‘an 
adhesive can be defi ned as a polymeric material which, when applied to 
surfaces, can join them together and resist separation’. Adams and co-
workers describe structural adhesives ‘as one used when the load required 
to cause separation is substantial such that the adhesive provides for the 
major strength and stiffness of the structure’. The structural members of the 
joint, which are joined together by the adhesive, are the adherends. Adhe-
sion as such is used widely on marine structures. One example is corrosion 
prevention coatings. However, for the purpose of this book we will focus 
2 Adhesives in marine engineering
© Woodhead Publishing Limited, 2012
on load-bearing applications with structural adhesives. The simplest joint 
confi guration is the single lap joint as shown in Fig. 1.1.
Why are adhesives being considered? The joining process is a conse-
quence of the materials used. In the case of adhesive bonding this could 
mean that the plates are too thin to weld, a particular material combination 
that cannot be welded, requirement for smooth surfaces for aesthetic 
reasons, to avoid hotwork and risk of fi re and fi nally corrosion management 
where the adhesive provides an insulating layer to avoid galvanic corrosion. 
No joining process comes without weaknesses. An adhesively bonded joint 
usually requires the adherends to overlap, the strength is temperature 
dependent and fabrication requires careful process control. Furthermore, 
there is a shortage of skilled designers and shipyard workers. A good discus-
sion of the pros and cons can be found in Lees (1990) which is still relevant 
today despite its age.
1.2 The need for adhesive bonding in the maritime 
and offshore industries
The aim of this section is to examine the motivation for using adhesive 
bonding. Adhesive bonding is an enabling technology allowing novel designs 
by joining multi-materials and lightweight materials. However, adhesive 
bonding is not a technology driver – adhesives are not used for the sake of 
using adhesives. A pertinent question therefore is what are the important 
S
b
d g
D F
lo
F
1.1 A single lap joint and its main parameters: F = tensile load, 
d = thickness of layer, S = thickness of adherend, b = width of joint, 
l0 = length of overlap region, γ = shear strain in adhesive, Δ = shear 
displacement due to F (from Weitzenböck and McGeorge, 2005).
 Introduction 3
© Woodhead Publishing Limited, 2012
industry trends and drivers that might affect and possibly favour the use of 
adhesive bonding in marine engineering. Future technology development 
is shaped by how the ‘world’ or society at large develops. DNV’s Technology 
Outlook (DNV Research and Innovation, 2011) identifi ed seven mega-
trends that are believed to have a signifi cant impact on that development 
until 2020. These mega-trends are: population, economy, governance, infor-
mation technology, energy, natural resources, climate change (see DNV 
Research and Innovation (2011)).
Based on these mega-trends, scenarios were developed to evaluate the 
impact on future technology development. Technology uptake was assessed 
for different industry sectors; three of these industry sectors fall within the 
scope of this book: maritime, oil and gas and wind energy. The list below 
shows technologies within these three industry sectors that may potentially 
be relevant for adhesive bonding, as they require joining of either multi-
materials or lightweight materials:
 The low energy ship. It is anticipated that in order to save weight and 
hence reduce fuel costs, the use of lightweight and hybrid materials will 
become more widespread.
 The green-fuelled ship. Signifi cant reductions in emissions such as SOx 
and particles can be achieved by switching to natural gas. The liquid 
natural gas (LNG) tanks used today require considerably more space 
than a diesel tank. New LNG tank concepts are under development 
using new material combinations to improve the current situation.
 The Arctic ship. Increased operations in the Arctic will require novel 
evacuation vessels that can also travel over ice, not just water. A number 
of material and joining issues are anticipated.
 The virtual ship. The use of integrated ship design tools will become 
more commonplace. This implies that joining processes including adhe-
sive bonding also need to be modelled in the designtools.
 Subsea production. Deployment of much larger subsea processing 
equipment is predicted, and with it comes the need for larger housing 
that is both water- and pressure-proof.
 Arctic offshore development. Signifi cant research and development is 
underway to qualify and characterise materials for the use in Arctic 
operations. An increase in use of lightweight materials such as compos-
ites and aluminium is predicted. This puts tough new requirements on 
the materials and joining methods such as adhesives, i.e. toughness at 
low temperatures. However, there is some experience of using adhesives 
for LNG containment systems at much lower temperatures (at about 
−163°C).
 Smart blade design. More sophisticated blade designs are anticipated 
within the next decade. This includes actuators for active control or new 
4 Adhesives in marine engineering
© Woodhead Publishing Limited, 2012
geometries or fi bre lay-ups that react to different loadings and wind 
speeds. These new designs will impose new requirements on the bonded 
joints used in the blades.
The list above is a discussion of the technology developments identifi ed in 
DNV’s Technology Outlook. It serves as an illustration on how new designs 
and material choices open up new possibilities for adhesives joining, but is 
by no means an exhaustive list. Further examples are shown later on in this 
chapter.
1.3 Potential uses of adhesives in the maritime and 
offshore industries
1.3.1 Maritime industry
There are a number of actual and potential applications for adhesive 
bonding in the maritime industry. However, this section will not focus on 
composite structures onboard ships. Composites are only mentioned when 
they are to be joined by adhesive bonding. More information about com-
posite applications including sandwich construction is found in Weitzen-
böck et al. (2010) or for the sandwich plate system (SPS) panels in Welch 
(2005). One of the fi rst general reviews of marine applications of adhesive 
bonding was by Wacker (2000). He reported the bonding of window panes, 
propeller shafts and FRP pleasure boats. There are some earlier accounts 
of using adhesives in a marine environment for particular applications. 
Reavey (1981) summarises many years of experience of bonding hovercraft 
structures successfully, mainly aluminium honeycomb. Even though these 
structures resemble aircraft structures, they are used in a marine environ-
ment. Interestingly, they chose a vinyl phenolic adhesive rather than an 
epoxy one as used in most studies reviewed in this section. A pioneering 
study by Hashim et al. (1989) proposed the use of hot curing epoxy adhesive 
to attach stiffeners to steel plates for structural ship applications. Results 
of fatigue and corrosion tests were presented.
Many applications are related to the superstructure of a ship. There are 
two main thrusts: to repair cracks in aluminium superstructures and to join 
lightweight structures made of composite or aluminium to the steel hull. 
Allan et al. (1988) report on a research programme to repair aluminium 
superstructures of Royal Navy warships by using composite patches that 
are bonded to the aluminium surfaces. They report on a comprehensive 
design and experimental study. Grabovac and Whittaker (2009) report on 
the long-term experience of using carbon-composite patches to repair 
cracks in an aluminium superstructure of an Australian Navy frigate. They 
summarise 15 years of experience with this type of repair; not only with the 
 Introduction 5
© Woodhead Publishing Limited, 2012
initial application of the composite patches but also in-service damage and 
wear and its subsequent repair. The authors believe this is a superior repair 
method for cracks with potential to be recognised as a permanent repair. 
There are no reports on applying bonded patch repairs to classed ships, such 
as container ships or oil tankers. However, there are considerable activities 
to repair fl oating objects, see also the section on oil and gas applications.
The paper by Reichard (1997) reports on a research project to develop 
composite superstructures for commercial ship application. He presents an 
innovative bonding process where adhesive tape and paste adhesive are 
combined to form the bonded connection between the composite and steel 
interfaces. A recent study describes the concept design of a composite 
superstructure for a roll on–roll off ferry (McGeorge et al., 2007). The 
authors employed risk-based design and demonstrated that both structural 
and fi re safety are at least as good as for a conventional superstructure. 
An important detail of composite superstructures is the joint between 
the superstructure and the steel deck. Most composite-steel joints are 
hybrid joints where adhesive bonding is combined with vertical members 
that limit potential movement in the in-plane direction as illustrated in Fig. 
1.2. Further information about hybrid joining can be found in Weitzenböck 
and McGeorge (2011). In order to facilitate more effi cient joining of 
composite superstructures to steel decks, a recent study looked at the pos-
sibilities of surface engineering methods for metal to composite joints in 
order to improve the durability of current bonded solutions (Smith and 
Hutapea, 2007).
A methodology for the design and construction of adhesively bonded 
aluminium superstructures was presented in Judd et al. (1996). In addition, 
the authors carried out some small scale materials tests. Cantrill et al. (2004) 
designed and constructed a full scale quarter section superstructure. They 
used a frame structure that was planked with aluminium plates. Both the 
plates and frame modules were joined by adhesive bonding.
Adhesive bonding is used in outfi tting of ships. Bonding of windows, or 
direct glazing, has become standard practice on passenger ships. The operat-
ing experience seems to indicate that there are no issues with adhesive 
joining (Weitzenböck, 2009). Bonded windows are typically hybrid solu-
tions where bonded joints are secured with additional bolts and metal strips 
as shown in Fig. 1.3. A discussion of the design and approval process can 
be found in Weitzenböck and McGeorge (2011). Another documented 
application on a fast ferry is the use of adhesive bonding to attach passenger 
seat mountings to lightweight aluminium decks using adhesive bonding 
(Anon, 1998).
A signifi cant application of adhesive bonding is the assembly of the sec-
ondary barrier of the membrane type containment systems for LNG carri-
ers (Weitzenböck, 2007). The majority of today’s LNG carriers on order 
6 Adhesives in marine engineering
© Woodhead Publishing Limited, 2012
Composite
face sheets
Balsa core
Steel plate
Bolts
Bolts Steel bulwark
Metal
Structure
B
alsa core
Sandwich
panel
Sandwich
(a) (b)
(c) (d) Deck
Welded steel
assembly
1.2 Hybrid joint concepts for composite superstructures: (a) and (d) 
glued fork or rail design; (b) and (c) bonded and bolted connection 
(with kind permission from Springer Science+Business Media: Hybrid 
adhesive joints, Science and Technology of Bolt-Adhesive Joints, 
2011, 6, p187, Weitzenböck and McGeorge, Fig. 1).
have membrane type containment systems. In the past few years there have 
been cases where the secondary barrier started to develop leaks. A number 
of researchers and companies are addressing this problem by developing 
new or improved processing routes; one example is shown in Kim and 
Lee (2008)
1.3.2 Oil and gas
There are not as many documented applications of structural adhesives in 
offshore structures. However, there is a large potential for use of adhesives 
as they can be used as a cold joining process, thus minimising the impact of 
maintenance work or modifi cations on oil production due to the greatly 
reduceddanger of explosions. One of the few documented examples is the 
use of fusion bonded epoxy to attach insulation materials to underwater 
pipelines and fl ow lines (Boye Hansen and Delesalle, 2000). These are very 
demanding applications as the design lifetime can be as much as 20 years 
without maintenance. During installation the pipes are reeled off which puts 
additional strain onto the pipeline insulation.
 Introduction 7
© Woodhead Publishing Limited, 2012
1.3 Bonded windows on a cruise ship. Note the small bolted metal 
strips where the corners of the window panes meet (with permission 
from Brombach & Gess).
Another important application of adhesive bonding is the use of 
bonded composite patches to repair FPSOs (fl oating, production, storage, 
offl oading) and other fl oating offshore structures as shown in Fig. 1.4 (see 
Echtermeyer et al. (2005) and McGeorge et al. (2009) for further details). 
The patch repair may be used to repair corroded or cracked steel details. 
One of the main attractions is that no hot work is involved and none of the 
oil production processes need to be closed. In the above mentioned refer-
ences, guidelines were developed to design and apply composite patches. 
Some fi eld repairs have already been carried out. This experience will be 
8 Adhesives in marine engineering
© Woodhead Publishing Limited, 2012
collected and documented in a forthcoming DNV Recommended Practice 
on bonded patch repair. A further important application of the composite 
patch repair is that of steel pipes. Gibson (2003) discusses the state of the 
art. There are a number of commercial providers of the materials and docu-
mented repair applications. Glass reinforced epoxy (GRE) composite pipes 
are used quite frequently offshore. One of the main joining methods is the 
use of adhesive bonding. Gibson (2003) provides a good overview of typical 
joint designs, mechanical performance and failure modes.
1.3.3 Wind energy
While the book does not attempt to address every aspect of the design, 
fabrication and operation of (offshore) wind turbines, it will nevertheless 
cover large wind turbine blades for offshore applications. They are large 
bonded composite structures. As discussed by Hayman et al. (2008), wind 
turbine blades are usually assembled from two half-shells and a central web 
or a main spar (also known as load-carrying box) by adhesive bonding. Due 
to the fact that these blades are mass produced, fabrication and application 
technology is quite advanced compared with most of the other adhesive 
applications discussed in this section. Moveable metering and dispensing 
pumps are used to apply several beads of adhesive needed to assemble the 
blade structure (Subrahmanian and Dubouloz, 2009). Also, blade repair 
techniques are being developed. As these repairs have to be made on site 
by technicians climbing up the blades, fast curing repair resins are impor-
tant. Marsh (2011) presented a repair technique that uses pre-pregs and a 
UV emitting light diode to accelerate the curing process.
Corrosion pits
or cracks
Bonded patch
Filler
Adhesive
layer
Steel plate
(a)
(b)
1.4 Outline of patch repair process: (a) damaged plate – crack/ 
corrosion pits; (b) composite patch was applied to restore structural 
integrity and/or stiffness.
 Introduction 9
© Woodhead Publishing Limited, 2012
1.4 Industry specifi c regulations and how to deal 
with them
New ship designs and offshore structures are developed in response to a 
commercial opportunity or need. Once the project has progressed from 
feasibility and concept studies to detailed design, the focus shifts towards 
technical issues. It is typically in this phase that adhesives may be consid-
ered. Before the new designs may be realised, they usually require approval 
by authorities and or classifi cation societies. Adhesively bonded joints will 
be scrutinised more closely if they are load-bearing and provide a system-
critical function.
Wind turbine blades are quite different to ship or oil and gas applications 
when it comes to approval or certifi cation. Adhesive bonding is an integral 
part of the blade design. It would simply not work without adhesives. There 
are a number of design guidelines and rulers for wind turbine blades; see 
for example Det Norske Veritas (2010a). The approval regime for the blades 
is closer to aircraft design than shipbuilding as full scale testing is required 
to verify static and fatigue performance over a 20 year lifetime. Design and 
testing of wind turbine blades will be addressed in more detail later on in 
the book.
All the remaining chapters of this book are concerned with material and 
joint performance, the testing and the fabrication of bonded joints. The fol-
lowing subsections are meant to point out to engineers and designers some 
of the main challenges in gaining approval for their bonded joint designs. 
They have at least one challenge in common: the lack of long-term experi-
ence of using adhesive bonding in a maritime environment for load-bearing 
(safety-critical) connections. It is not realistic to require full scale testing to 
simulate this as is common for wind turbine blades. An approach for dealing 
with the uncertainty will be presented at the end of this section.
1.4.1 Ship classifi cation
Ship classifi cation is defi ned in Part 0 Chapter 2 of the DNV rules (Det 
Norske Veritas, 2003) as ‘the process of verifying ship standards against a 
set of requirements. The requirements are laid down in the rules established 
by the classifi cation society. Classifi cation implies that the ship is surveyed 
during construction on the basis of design approval, tested before taken 
into service and surveyed regularly during its whole operational life until 
scrapping.’ National authorities (fl ag authorities) have responsibility for the 
total safety control of ships fl ying their national fl ag. This includes fi re pro-
tection and fi re fi ghting, lifesaving equipment and safety management 
systems. Many national authorities have delegated this responsibility to 
classifi cation societies authorising them to work and certify on their behalf.
10 Adhesives in marine engineering
© Woodhead Publishing Limited, 2012
Classifi cation societies issue rules setting requirements for the design, 
construction survey and testing of vessels. Many regulations in the interna-
tional maritime conventions have been adopted in the class rules. In general, 
rules cover the structural strength and where relevant the watertight integ-
rity and integrity of essential parts of the vessel’s hull and its appendages, 
and the safety and availability of the main functions in order to maintain 
essential services (see also Det Norske Veritas, 2011a). Furthermore, the 
rules provide requirements for certifi cation of materials, components and 
systems for use on ships approved by a particular classifi cation society (Det 
Norske Veritas, 2010b).
Adhesive bonding is still a relatively new joining process in shipbuilding 
with limited or no previous experience. Currently, there are very few clas-
sifi cation rules or requirements for approval of adhesively bonded joints 
which in turn discourages many to consider adhesive bonding as part of 
their design. Most approvals today are based on case by case approval.
In response to radical new ship designs, classifi cation rules now permit 
the use of risk based assessment as a means of showing compliance with 
rule requirements. This is based on the guidelines for Formal Safety Assess-
ment published by the International Maritime Organisation (IMO) (2002). 
Alternatives to, or deviations from, requirements in the rules may now be 
accepted when the overall safety and reliability level is equivalent to or 
better than that of current rules (see also B610 in Det Norske Veritas(2011a)). In this assessment one needs to demonstrate equivalent safety, in 
particular fi re safety. It is therefore important to involve fl ag authorities in 
the process.
1.4.2 Offshore installations
Offshore installations are regulated by national authorities. According to 
the Norwegian Petroleum Act, the owner is fully responsible for verifi cation 
activities ensuring that the unit/ installation and related operations are in 
compliance with the applicable regulatory requirements (Det Norske 
Veritas, 2007). The owner can utilise internal as well as external verifi cation 
to demonstrate compliance with his verifi cation obligations. The regulatory 
body on the Norwegian Continental Shelf is the Petroleum Safety Author-
ity (PSA). The PSA regulations make a distinction between mobile facilities 
and other offshore installations. Mobile (buoyant) units are in this context 
understood as units registered in a national register of shipping, and which 
follow a maritime concept and are classed as ships. One such example is 
drilling units.
The UK sector of the North Sea has its own regulatory regime. The UK 
Safety Case Regulations (SCR) and Prevention of Fire and Explosion and 
Emergency Response Regulations (PFEER) require that all major accident 
hazards pertaining to an offshore installation are identifi ed and adequately 
 Introduction 11
© Woodhead Publishing Limited, 2012
managed throughout the installation lifecycle (Det Norske Veritas, 2011b). 
This is achieved by a combination of assessment and verifi cation to assure 
an acceptable standard of integrity of the installation, safety of operation 
and protection of personnel. The regulations establish a non-prescriptive 
‘goal setting’ approach which enables efforts to be focused on those items 
which provide the greatest contribution to safety. This implies that risks 
from major accident hazards are assessed and reduced to a level that is as 
low as reasonably practicable (ALARP). ALARP means that once risks 
are considered to be tolerable, further risk reduction measures are balanced 
against the cost of implementing such measures.
As discussed above, offshore installations require independent verifi ca-
tion in order to gain approval from the shelf regulators. One approach is 
the risk-based verifi cation process defi ned in Det Norske Veritas (2004) and 
summarised in Fig. 1.5. The term ‘asset’ is used to denote an onshore or 
Asset planned
Asset completed
Asset specification
including overall company acceptance
criteria and verification objectives
Risk assessment
including identification of hazards and
ranking of hazards based on risk
evaluation
Definition of verification involvement
including detailing of acceptance criteria
Verification plan
including list of verification activities
Verification execution
including reporting of compliance or non-
compliance
1.5 Flow chart of the risk-based verifi cation process (from Det Norske 
Veritas, 2004).
12 Adhesives in marine engineering
© Woodhead Publishing Limited, 2012
offshore installation or part thereof, a system or process, or a development 
phase such as feasibility, design, construction, commissioning, operation and 
decommissioning. The requirements of current approval processes are 
based on risk-based assessments with independent verifi cation. Joining 
methods are not mentioned explicitly. However, they are one of the princi-
pal items that (can) limit the durability and reliability of structures. The 
performance of an adhesively bonded joint is thus tested and documented 
for each case, for example attachment of a composite component to a 
steel structure. A re-occurring dilemma is that it is very costly and time-
consuming to demonstrate that adhesively bonded joints have a long-term 
performance of perhaps 15 or more years as there are no reliable short-term 
tests to predict lifetime.
1.4.3 Approval of bonded joints
Risk assessment to show compliance or equivalence is used routinely in the 
offshore industry and was recently also introduced for ships. The identifi ca-
tion of hazards and risks and selection of the best risk control options is 
usually done according to the IMO guidelines for formal safety assessment 
(FSA) (IMO, 2002). There are fi ve steps:
 Step 1: Identifi cation of hazards
 Step 2: Risk analysis
 Step 3: Risk control options
 Step 4: Cost benefi t assessment
 Step 5: Recommendations for decision making.
These fi ve steps represent a generally accepted structured approach to risk 
assessment and decision making. This concept provides the background for 
a pragmatic approach to approval of adhesively bonded joints. It was fi rst 
presented by Weitzenböck and McGeorge (2004) and comprises the follow-
ing three steps:
1. Hazard identifi cation
2. Risk assessment
3. Adoption of suitable risk control measures.
Three generic risk control options were proposed by Weitzenböck and 
McGeorge (2004):
 Use of best practice in material selection, joint design and fabrication 
technology.
 Ensure that the design allows detection of damage before ultimate 
failure. Furthermore, a design needs to have suffi cient reserve strength 
and/ or redundancy so that ‘detectable damage’ is tolerable.
 Introduction 13
© Woodhead Publishing Limited, 2012
 Develop and demonstrate repair procedures to be able to repair the 
detected damage.
The attraction of this approach is that one avoids the diffi cult task of 
demonstrating long-term performance a priori and thus paving the way 
for a more widespread application of adhesive bonding. The potential 
drawback is that one is limited to those applications that tolerate 
initial failure until it is detected. This could be achieved with a hybrid 
joint design, where a mechanical fastener is combined with adhesive 
bonding; see also Weitzenböck and McGeorge (2011). An example of 
how bonded joints are assessed and classifi ed according to their criticality 
and need for documentation is provided by McGeorge et al. (2009). The 
authors presented a classifi cation system to identify reliability classes pro-
posed for composite bonded repair of fl oating offshore units. Moreover, the 
authors clearly identify those cases which are outside the scope their repair 
scheme because of their criticality and need for extensive and expensive 
testing.
1.5 Future trends
The wind energy industry is expected to grow considerably over the next 
few years, mainly offshore. The wind turbines are expected to grow in size 
and possible functionality. This will pose new challenges to ever increasing 
blades and their constituent materials. Strength and stiffness requirements 
will increase as well as reliability of the blades as they are much more dif-
fi cult to repair offshore. Hence the use of adhesives will continue to grow 
and with it the need for improved performance and reliability.
Adhesive bonding in marine and offshore applications is still very much 
in its infancy in spite of some successes. However, much is still needed to 
establish this joining process as a standard process in shipbuilding or off-
shore. What should or will happen in the next ten years, for example one 
obvious development is to move away from the ‘special process’ and case 
by case design and approval to standardise adhesive bonding by pre-
qualifying applications and joint designs, materials and processes and 
people and inspection regimes. Furthermore, adhesively bonded joints need 
to be represented in fi nite element software and computer aided design 
software. This would allow simply specifying the joint using some kind of 
catalogue rather than having to design a solution for each application, 
thus speeding up the design and approval process considerably and also 
removing the risk of not getting approval.
What is also needed is more transparencyin the decision making process. 
It is important that those taking the decision to use adhesive bonding 
involve those who are left with the uncertainty or potential risk of using 
14 Adhesives in marine engineering
© Woodhead Publishing Limited, 2012
adhesive, for example the shipyard and ship owner. Due to the limited 
long-term experience of using adhesives in a marine environment one needs 
to gain experience by focusing on low risk applications and non-critical 
joints fi rst. Another possibility is the more widespread use of hybrid joints 
where the best of both worlds are combined to join components by using 
adhesives and a mechanical device.
1.6 References
Adams, R. D., Comyn, J. and Wake, W. C. 1997. Structural Adhesive Joints in Engi-
neering, London, Chapman & Hall.
Allan, R. C., Bird, J. and Clarke, J. D. 1988. Use of adhesives in repair of cracks in 
ship structures. Materials Science and Technology, 4, 853–859.
Anon 1998. Sonderfahrzeugbau: Kleben als Alternative zum Nieten oder Schweis-
sen (Adhesive bonding as alternative to riveting or welding – in German). Adhä-
sion KLEBEN & DICHTEN, 42, 4.
Boye Hansen, A. and Delesalle, A. 2000. Cost effective thermal insulation systems 
for deepwater West Afrika in combination with direct heating. Offshore West 
Africa 2000 Conference and Exhibition. Abidjan, Ivory Coast.
Cantrill, J., Kapadia, A. and Pugh, D. 2004. Lessons learnt from designing and pro-
ducing adhesively bonded prototyping structures in a shipyard. Proc. Instn Mech. 
Engrs Part M: J. Engineering for the Maritime Environment, 218, 267–272.
Det Norske Veritas. 2003. Introduction to Ship Classifi cation, Part 0, Chapter 2. 
Rules for Classifi cation of Ships [Online]. Available: http://exchange.dnv.com/
publishing/RulesShip/2011-07/ts002.pdf [Accessed 20.11.2011].
Det Norske Veritas. 2004. Risk Based Verifi cation. Offshore Service Specifi cation 
DNV-OSS-300 [Online]. Available: http://exchange.dnv.com/publishing/Codes/
download.asp?url=2004-04/oss-300.pdf [Accessed 20.11.2011].
Det Norske Veritas. 2007. Verifi cation for Compliance with Norwegian Shelf Regu-
lations. Offshore Service Specifi cation DNV-OSS-201 [Online]. Available: http://
exchange.dnv.com/publishing/Codes/download.asp?url=2010-04/oss-201.pdf 
[Accessed 20.11.2011].
Det Norske Veritas. 2010a. Design and Manufacture of Wind Turbine Blades, 
Offshore and Onshore Wind Turbines. DNV Standard, DNV-DS-J102 [Online]. 
Available: http://exchange.dnv.com/publishing/Codes/download.asp?url=2010-11/
ds-j102.pdf [Accessed 20.11.2011].
Det Norske Veritas. 2010b. Fabrication and Testing of Ship Structures, Part 2, 
Chapter 3. Rules for Classifi cation of Ships, High Speed, Light Craft and Naval 
Surface Craft [Online]. Available: http://exchange.dnv.com/publishing/
RulesHSLC/2011-07/ts203.pdf [Accessed 20.11.2011].
Det Norske Veritas. 2011a. General Regulations, Part 1, Chapter 1. Rules for 
Classifi cation of Ships [Online]. Available: http://exchange.dnv.com/publishing/
RulesShip/2011-07/ts101.pdf [Accessed 20.11.2011].
Det Norske Veritas. 2011b. Verifi cation for Compliance with UK Shelf Regulations. 
Offshore Service Specifi cation, DNV-OSS-202 [Online]. Available: http://exchange.
dnv.com/publishing/Codes/download.asp?url=2011-04/oss-202.pdf [Accessed 
20.11.2011].
 Introduction 15
© Woodhead Publishing Limited, 2012
DNV Research and Innovation. 2011. Technology outlook 2020. Available: http://
www.dnv.com/moreondnv/research_innovation/foresight/outlook/index.asp 
[Accessed 20.11.2011].
Echtermeyer, A. T., McGeorge, D., Sund, O. E., Andresen, H. W. and Fischer, K. P. 
2005. Repair of FPSO with Composite Patches. Fourth International Conference 
On Composite Materials For Offshore Operations. Houston, TX.
Gibson, A. G. 2003. The cost effective use of fi bre reinforced composites offshore, 
UK, HSE Health & Safety Executive.
Grabovac, I. and Whittaker, D. 2009. Application of bonded composites in the repair 
of ships structures – A 15-year service experience. Composite Part A, 40, 
1381–1398.
Hashim, S. A., Winkle, I. E. and Cowling, M. J. 1989. A Structural Role for Adhesives 
in Shipbuilding? Meeting of the Royal Institution of Naval Architects. London: The 
Royal Institution of Naval Architects.
Hayman, B., Wedel-Heinen, J. and Brøndsted, P. 2008. Materials challenges in present 
and future wind energy. MRS Bulletin, 33, 343–353.
IMO 2002. Guidelines for Formal Safety Assessment (FSA) for use in the IMO rule 
making process. London: International Maritime Organisation, MSC/Circ. 1023.
Judd, G., Dodkins, A. and Maddison, A. 1996. Adhesively bonded aluminium super-
structures. International Conference on Lightweight Materials in Naval Architec-
ture. Southampton: The Royal Institution of Naval Architects.
Kim, B. G. and Lee, D. G. 2008. Leakage characteristics of the glass fabric composite 
barriers of LNG ships. Composite Structures, 86, 27–36.
Lees, W. A. 1990. Bonded assembly – pros, cons and ground rules. Materials and 
Design, 11, 227–234.
Marsh, G. 2011. Meeting the challenge of wind turbine blade repair. Reinforced 
Plastics, 55, 32–36.
McGeorge, D., Echtermeyer, A. T., Leong, K. H., Melve, B., Robinson, M. and 
Fischer, K. P. 2009. Repair of fl oating offshore units using bonded fi bre composite 
materials. Composites Part A: Applied Science and Manufacturing, 40, 
1364–1380.
McGeorge, D., Høyning, B. and Nordhammar, H. 2007. Risk based design – a case 
study on composite superstructures. SAFEDOR Mid-Term Conference. Brussels: 
The Royal Institution of Naval Architects.
Reavey, D. G. 1981. Marine experience of structural adhesives in hovercraft. SAMPE 
Journal, September/ October, 18–21.
Reichard, R. P. 1997. Low cost topside structures for commercial ship applications. 
Anaheim, CA, USA: SAMPE.
Smith, M. and Hutapea, P. 2007. Surface engineering for adhesively bonded metal-
composite joints. Journal of Ship Production, 23, 72–81.
Subrahmanian, K. P. and Dubouloz, F. 2009. Adhesives for bonding wind turbine 
blades. Reinforced Plastics, 53, 26–29.
Wacker, G. 2000. Adhesive Joining – A New Joining Technology for Shipbuilding 
(in German). Handbuch der Werften. Hamburg: Schiffahrtsverlag Hansa.
Weitzenböck, J. R. 2007. Adhesive bonding of containment systems for LNG carri-
ers. SwissBonding. Rapperswil, Switzerland.
Weitzenböck, J. 2009. Sticking point. Materials World, 17, 22–23.
Weitzenböck, J. R., Hayman, B., Hersvik, G., McGeorge, D., Noury, P., Hill, D. M. 
and Echtermeyer, A. 2010. Application of composites in ships and offshore – A 
16 Adhesives in marine engineering
© Woodhead Publishing Limited, 2012
review and outlook. International Conference on Marine and Offshore Compos-
ites. London.
Weitzenböck, J. R. and McGeorge, D. 2004. The designer’s dilemma: How to deal 
with the uncertainty about the long-term performance of adhesively bonded 
joints. Proc. Instn Mech. Engrs Part M: J. Engineering for the Maritime Environ-
ment, 218, 273–276.
Weitzenböck, J. R. and McGeorge, D. (eds.) 2005. BONDSHIP project guidelines, 
Høvik, Norway: Det Norske Veritas AS.
Weitzenböck, J. R. and McGeorge, D. 2011. Science and technology of bolt-
adhesive joints. In: Da Silva, L. F. M., Pirondi, A. and Öchsner, A. (eds.) Hybrid 
adhesive joints. Berlin Heidelberg: Springer-Verlag.
Welch, D. 2005. The Sandwich Plate System. Presentation at the Glasgow College of 
Nautical Studies. Glasgow: I.Mar.EST/IESIS.
© Woodhead Publishing Limited, 2012
19
2
Selecting adhesives for marine environments 
and pre-design
J. R. W E I T Z E N B Ö C K, Det Norske Veritas AS, Norway
Abstract: The purpose of this chapter is to defi ne a framework for the 
selection of adhesives. Moreover, the interaction between adhesive 
selection and (ship) design will be explored. Design for adhesives 
implies design forproduction as the fabrication determines the quality 
of the bonded joint. A comprehensive framework for adhesive selection 
is presented which addresses both materials selection and fabrication 
process selection. It starts by specifying requirements followed by 
screening tests for preliminary selection. Simple formulae for pre-design 
of bonded connections are provided in order to assess feasibility. Links 
to further information about adhesive selection are included.
Key words: adhesive bonding, material selection, adhesive selection, 
design, ship building, marine engineering, offshore, pre-design, 
requirement lists.
2.1 Introduction: the rationale for adhesive selection
The aim of this chapter is to outline a selection process for adhesives in a 
marine environment. The selection process encompasses both material and 
process selection. While the purpose of this book is to provide an overview 
of the use of adhesives in marine environments, it is nevertheless important 
to refl ect upon when adhesives should be used, and when not. Adhesive 
bonding is a joining method with many advantages, but it is not always the 
best joining process for a given problem.
Why is material selection important? Many ships or offshore installations 
are built using standard material specifi cations. However, recent develop-
ments such as making shipping more environmentally friendly or arctic 
operations require that traditional solutions need to be re-examined and 
new design solutions are being developed. In many cases new materials are 
introduced and with them the need for new joining methods. Adhesive 
bonding is a joining process where the fi nal material properties are created 
during processing and application of the adhesive. Many designers of 
bonded joints are mainly concerned with the short- and long-term mechani-
cal performance of the adhesively bonded joint. What is not always appar-
ent is that by selecting a specifi c type of adhesive, most of the manufacturing 
20 Adhesives in marine engineering
© Woodhead Publishing Limited, 2012
parameters are decided as well. Hence information about fabrication 
aspects is also crucial for the designer of bonded joints, more so than with 
traditional materials such as steel.
2.1.1 The link between design, material selection 
and fabrication
A design is initiated by defi ning a market need or new idea and a statement 
specifying what task this device will actually perform and the requirements 
that have to be fulfi lled (Pahl et al., 2007). It is usually documented in a list 
of requirements. This is followed by conceptual design, embodiment design 
and fi nally detailed design. These different design phases are used to specify 
functions and working principles, overall layout and fi nally the arrange-
ments, forms, dimensions and materials are specifi ed. All the different stages 
of design require information about the materials being used. The scope 
and degree of detail varies from all/many materials with low precision and 
detail for concept design to one material and high precision and detail for 
detailed design (Ashby, 2007).
The motivation for selecting or changing the existing material choice 
depends also on the type of design (Ashby, 2007). For a new design, new 
materials with unique properties can be exploited. Sometimes design needs 
drive materials development, for example, lightweight materials for ships. 
When adaptive design takes place, existing materials are sometimes replaced 
to improve performance, such as the use of glass fi bre composites for skis 
instead of wood. Variant design may sometime lead to material change 
because, for example, the current material choice will not meet the stiffness 
requirements for the longer variant. Another reason for material substitu-
tion could be quality problems, such as corrosion, that require the selection 
of a new material. An interesting observation is that text books on design 
almost never mention materials. Pahl et al. (2007) refer to materials in their 
index once – in the cost estimation chapter. However, as Fig. 2.1 illustrates, 
there are many interactions between function, material, shape and process. 
As Ashby puts it, the shape, both macro-shape and micro-shape, such as a 
panel made of honeycomb, is subject to a (manufacturing) process to be 
able to produce it (Ashby, 2007). This includes forming and joining pro-
cesses. A process is infl uenced by the material and it interacts with the 
shape. Function dictates materials and shape.
Materials are usually only considered in the earlier phases of the 
design process of marine structures when they affect the global design, 
For example, to:
 save weight in order to reduce fuel consumption and emissions, improve 
stability and increase payload,
 Adhesives for marine environments and pre-design 21
© Woodhead Publishing Limited, 2012
 reduce price – not only of new construction, but also lifetime cost 
through reduced maintenance and increased lifetime,
 modify/upgrade existing designs: the additional structure needs to be as 
light as possible to minimise impact on stability and fuel consumption. 
In many ways, new materials, such as composites, enable modifi cation 
of ships and redeployment to new services,
 simplify recycling of ships in the future and possibly reduce the CO2 
footprint of ship building.
The joining process is a consequence of the materials used. In the case of 
adhesive bonding this could mean that the plates are too thin to weld, a 
particular material combination that cannot be welded, requirement for 
smooth surfaces for aesthetic reasons, and corrosion management – to have 
an ‘insulating’ layer between the materials to be joined.
2.1.2 Design for adhesive bonding
Adhesive selection is part of the initial design process when not all the 
details of the design have been decided. It is therefore useful to review 
briefl y the factors that make a design more adhesive friendly. One of the 
most important processes in achieving this is ‘design for production’. Why 
is design for production important? Adhesive selection focuses on selecting 
adhesives for their mechanical performance. The designer is not always 
aware that by selecting a particular material he or she also specifi es a fab-
rication process and joining method. Hence it is even more important for 
a designer to consider fabrication and assembly early on in the process.
Ashby has proposed some simple rules for designers to minimise process-
ing costs (Ashby, 2007, p203):
Shape
Material
ProcessFunction
2.1 The interaction between function, material, shape and process 
(after Ashby, 2007).
22 Adhesives in marine engineering
© Woodhead Publishing Limited, 2012
 ‘Keep things standard’: to minimise inventory costs, use standard mate-
rials and components.
 ‘Keep things simple’: to minimise the number of process steps required 
to make the component. This includes ease of access, e.g. for an adhesive 
gun or to what extent clamping is needed.
 ‘Make the parts easy to assemble’: to minimise the assembly time (and 
cost). This is mainly achieved by minimising part count, by designing 
components to be self-aligning on assembly and by using fast joining 
methods.
 ‘Do not specify more performance than needed’: high performance 
materials have stricter processing requirements; hence, specifying too 
high performance not only leads to increase in materials costs, but also 
processing costs.
Design for assembly is another important element in an ‘adhesive-
friendly’ design. Pahl et al. (2007) argue that design for assembly should at 
least consider the following operations:
 storing of parts to be assembled
 handling of components, including identifying and moving the parts
 positioning or placing the part correctly and aligning it before joining
 joiningprocess – here of course adhesive bonding
 adjusting to equalise tolerances
 securing the assembled parts against unwanted movement
 inspecting.
Datsko developed his 11 ‘Datsko’s Design Rules for Optimal Produce-
ability’ (Datsko, 1997). Many are similar to those mentioned previously. 
However, the following rules have not been considered yet and are added 
for completeness:
 Select the material on the basis of ease of fabrication as well as function 
and cost. It is important to remember that each adhesive has its own 
chemistry and specifi c requirements for the fabrication process due to 
different curing mechanisms (e.g. heat or humidity).
 Provide clamping, locating and measuring surfaces. This is important for 
the assembly of bonded structures.
 Evaluate the preliminary design and consider changes in the confi gura-
tion that will simplify the fabrication, then go through the design rules 
again. Repeat until the optimal design is achieved.
2.2 Material and process selection
Material and process selection is an iterative solution-fi nding process. One 
of the conceptual challenges with adhesive bonding is that one selects an 
 Adhesives for marine environments and pre-design 23
© Woodhead Publishing Limited, 2012
adhesive for its mechanical performance but at the same time also selects 
a joining process. Ashby presented a systematic approach to selecting mate-
rials and fabrication processes (Ashby, 2007). He developed a structured 
process for selecting materials in mechanical designs. It is based on a four 
step approach:
(i) translate design requirements: express as function, constraints, objec-
tives and free variables,
(ii) screen using constraints: eliminate materials that cannot do the job,
(iii) rank using objective: fi nd the screened materials that do the job best 
and fi nally
(iv) seek supporting information: research the family history of the top-
ranked candidates.
In parallel to the material selection, Ashby also introduces a method for 
selecting appropriate processing routes for the material and product. It is 
also divided into four steps:
(i) translate design requirements: the design requirements are expressed 
as constraints on material, shape, size, tolerance, and other process 
related parameters.
(ii) screen using constraints: eliminate processes that cannot meet the 
translated design requirements.
(iii) rank using objective: order by relative cost or batch size and fi nally
(iv) seek supporting information: research history and experience with the 
top ranked processes.
Reuter (2007) extends part of the approach by Ashby. Rather than simply 
seeking supporting information, he uses ‘verifi cation’ of the material selec-
tion as the fi nal step. This can be based partly on a risk analysis such as 
Fault-Tree Analysis and mostly on verifi cation by calculation and testing of 
the selected material. While Ashby’s method is widely recognised, it needs 
to be modifi ed nonetheless to adjust to the particular requirements of 
adhesive bonding, i.e. the need to select process and material simultane-
ously. The fi nal material selection depends to a considerable degree on local 
conditions. As both Ashby and Reuter point out, previous experience, avail-
able knowledge and production capabilities are the main selection factors. 
This may mean that the selected material is not always the ‘best’ material 
for the particular design.
This chapter will not discuss the different types of adhesives as this infor-
mation can readily be found in other publications. For a brief introduction 
see for example (Lees, 1988, 1991) while a comprehensive overview can be 
found in Packham (2005) and section 2 of Brinson (1990). For information 
about commercial products see technical information from the different 
24 Adhesives in marine engineering
© Woodhead Publishing Limited, 2012
adhesive suppliers. Moreover, the surface preparation of the adherends is 
not considered in this chapter.
2.3 Adhesive selection step 1: 
translate design requirements
The fi rst task in the selection process is to establish suitable selection 
criteria and optimisation objectives. Adhesive bonding is a joining process 
used to assemble structures and structural elements. Hence, one will get 
the relevant information from the design requirements. This information 
needs to be translated in order to identify the adhesive specifi c criteria and 
optimisation objective. A very comprehensive approach to specifying 
requirements was presented by Pahl et al. (2007) and is shown in Table 2.1. 
It covers design, fabrication, operation and maintenance of the component. 
Each item on this list will be classifi ed according to how important it is. 
D = demand: must be met at all circumstances; W = wishes: should be taken 
into consideration. This table should also include quantitative (e.g. numbers 
and magnitudes such as number of items, maximum weight, power output) 
and qualitative (e.g. permissible variation, waterproof, corrosion proof) 
criteria.
Next, the requirements on design and process are expressed as function, 
constraints, objective and free variables as shown in Table 2.2 and Table 2.3. 
A typical result for process requirements is shown in Table 2.4. When it 
comes to the optimisation objective there is probably only one – minimisa-
tion of cost! When costing the process, one should also consider savings 
further down the line such as reduced time for rectifi cation of distorted 
structures or repair of damaged coating.
2.3.1 Pre-design
The design and process requirements say little or nothing about the con-
fi guration or loading of the bonded joint. In particular for applications that 
are new, with no similar previous examples, it may be useful to get some 
initial idea about possible joint confi guration, estimate of the loading of the 
adhesive and joint dimensions. The initial assumption must be confi rmed 
later on in step 4 of the selection process. There are many catalogues of 
bonded joint confi gurations; a possible starting point is Section 5.1.2 in 
Weitzenböck and McGeorge (2005) and Adams et al. (1997).
Adhesively bonded joints should be loaded in shear where they are 
strongest. For signifi cant loads in out-of-plane direction one should consider 
redesigning the joint to reduce the infl uence of peel loading. Another option 
might be the use of hybrid joining methods as discussed for example in 
 Adhesives for marine environments and pre-design 25
© Woodhead Publishing Limited, 2012
Table 2.1 Requirement list (Pahl et al., 2007)
Main headings Examples
Geometry Size, height, width, length, diameter, space requirements, 
number, arrangement, connection, extension
Kinematics Type of motion, direction of motion, velocity, acceleration
Forces Direction of force, magnitude of force, frequency, weight, 
load, deformation, stiffness, elasticity, inertia force, 
resonance
Energy Output, effi ciency, loss, friction, ventilation, state, pressure, 
temperature, heating, cooling, supply, storage, capacity, 
conversion
Material Flow and transport of materials, physical and chemical 
properties of the initial and fi nal product, auxiliary 
materials, prescribed materials (food regulation etc.)
Signals Inputs and outputs, form, display, control equipment
Safety Direct safety systems, operational and environmental safety
Ergonomics Man–machine relationship, type of operation, operating 
height, clarity of layout, sitting comfort, lighting, shape 
compatibility
Production Factory limitations, maximum possible dimensions, 
preferred production methods, means of production, 
achievable quality and tolerances, wastage
Quality control Possibilities of testing and measuring, application of special 
regulations and standards
Assembly Special regulations, installation, siting, foundationsTransport Limitations due to lifting gear, clearance, means of transport 
(height and weight), nature and conditions of despatch
Operation Quietness, wear, special uses, marketing area, destination 
(e.g. sulphurous atmosphere, tropical conditions)
Maintenance Servicing intervals (if any), inspection, exchange and repair, 
painting, cleaning
Recycling Reuse, reprocessing, waste disposal, storage
Costs Maximum permissible manufacturing cost, cost of tooling, 
investment and depreciation
Schedules End date of development, project planning and control, 
delivery date
Table 2.2 Translation of design requirements (after Ashby, 2007)
Function What does component do?
Constraints What non-negotiable conditions must be met?
What are the negotiable but desirable conditions?
Objective What is to be maximised or minimised?
Free variables What parameters of the problem is the designer free to 
change?
26 Adhesives in marine engineering
© Woodhead Publishing Limited, 2012
Table 2.3 Translation of process requirements (after Ashby, 2007)
Function What must the process do? (Shape, join, fi nish?)
Constraints What material, shape, size, precision, etc. must it provide?
Objective What is to be maximised or minimised? (Cost, time, quality?)
Free variables Choice of process/process chain options
Table 2.4 Translation of process requirements (Table 2.3 and Weitzenböck and 
McGeorge, 2005)
Function What must the process do? (i) Join two (dissimilar) materials, 
(ii) mix different adhesive component (two or one), (iii) 
control viscosity by varying temperature, (iv) provide 
suffi cient humidity for humidity curing adhesives to cure
Constraints What material, shape, size, precision, etc. must it provide? 
(i) Must be able to accommodate fairly large bond line 
thicknesses – tolerance of components to be joined 
(>10 mm), (ii) have a certain handing strength after a given 
time to achieve desired throughput, (iii) mainly fl at, parallel 
interfaces, (iv) large bonding surfaces with corresponding 
extended open time (typically >30 minutes), (v) materials: 
different steel alloys, different aluminium alloys, 
composites, (vi) one-component polyurethane humidity 
adhesives can take weeks to cure, (vii) control of bonding 
conditions – e.g. humidity, surface cleanliness and structure 
and application temperature
Objective What is to be maximised or minimised? Cost is to be 
minimised – cheaper than a welded solution while quality is 
to be maximised to achieve expected lifetime and reliability
Free variables Choice of process/process chain options. Select adhesive 
chemistry to eliminate some of the constraints – the 
optimal solution is very dependent on the application case. 
Will it be used for small or large batch sizes? Will it be used 
in a controlled workshop or in the dock?
Weitzenböck and McGeorge (2011). The following formulae apply to in-
plane shear.
For fl exible adhesives, Burchardt et al. (1998) propose the following for-
mulae to determine lap-shear strength:
A S
F
f
S
F
A f
K K
Shear
B t
B K
Shear
K t
or= =
τ
τ [2.1]
with
AK = area of bond face
SK = safety factor
 Adhesives for marine environments and pre-design 27
© Woodhead Publishing Limited, 2012
ft = reduction factor for exposure to constant static stress
τB = lap-shear strength
FShear = shear force
Burchardt et al. specify a minimum safety factor of 2 and reduction factor 
of 0.06 for exposure to constant static stress.
Bigwood and Crocombe proposed a closed form solution that can be 
applied to stiff adhesives in L- and T-joints, T-peel and single lap joints 
(Bigwood and Crocombe, 1989). Even though the formulae are more 
complex, once implemented in a spreadsheet they are easy to use. It is pos-
sible to compute both shear and peel stresses in the adhesive.
Another important piece of information early on is the minimum overlap 
length of the bonded connection. Brede developed simple formulae for 
determining the minimum overlap length of a lap-shear joint (Section 11.2 
in Weitzenböck and McGeorge, 2005):
l
E s d
G
E s
E s
G l
E s d
* =
+( ) = = +( )
∗ρ δ δ ρ δ
1 1 1 1
2 2
2
1 11
1with and [2.2]
with
l* = minimum overlap length
l = overlap length
E1 and E2 = Young’s modulus of adherends 1 and 2
s1 and s2 = thickness of adherends 1 and 2
d = thickness of adhesive layer
G = shear stiffness of adhesive
The minimum overlap length l* is estimated by selecting ρ to be 5 in Equa-
tion [2.2]. Experience has shown that increasing ρ beyond 5 does not lead 
to any signifi cant changes in the stress distribution.
Bigwood and Crocombe (1989), Burchardt et al. (1998) and Weitzenböck 
and McGeorge (2005, Section 11.2) provide an estimate of the linear elastic 
behaviour of bonded joints – they should not be used for predicting failure. 
However, because of their simplicity the formulae can be used to get a fi rst 
estimate of the required adhesive performance. This needs to be confi rmed 
and refi ned later on (see also step 4 of the selection process).
2.4 Adhesive selection step 2: 
screen using constraints
The results of the previous exercise form the basis for identifying adhesives 
that are suitable for the job. Some of the constraints formulated above will 
exclude certain adhesives. For example gap fi lling capabilities, operating 
temperature, loading requirements will only be met by some adhesives. As 
28 Adhesives in marine engineering
© Woodhead Publishing Limited, 2012
Lees remarked (Lees, 1995), even though the individual requirements may 
be quite vague, the fact that there are many of them results in quite a fi ne 
‘fi lter’. In practical terms, one usually approaches adhesive suppliers with 
the list of requirements and asks them to recommend suitable products 
from their range of adhesives.
2.5 Adhesive selection step 3: rank using objective
The aim of this step is to fi nd the screened materials that do the job best 
and to rank the (adhesive) joining processes by relative cost or batch size. 
Here the optimisation objective is used to prioritise the different candidate 
adhesives. Ashby (2007) has developed a material index to compute a solu-
tions space for possible candidate materials. This can easily be done using 
his general material selection CES software. However, for adhesives it is 
often diffi cult to defi ne absolute performance criteria. It is therefore up to 
the designers and engineers to make the fi nal selection.
2.5.1 Ranking mechanical performance by screening tests
Many maritime applications are unique. Materials or the surface coatings 
used are usually different from one application to another. Hence, there is 
rarely detailed information about the mechanical performance of the adhe-
sives being considered for the material confi guration used in the new design. 
It is therefore quite common to carry out screening tests in order to assess 
the pre-selected adhesives. The methods described in this section are com-
monly used for screening purposes. They are simple to carry out which is 
important when many combinations are to be examined. The test results do 
not always result in an absolute value but can be compared with the other 
competing adhesives. While these tests provide some basic material char-
acterisation, they may not be suffi cient to provide the required input to 
some of the advanced analysis methods used elsewhere in the book. Most 
of the test procedures can be found in Weitzenböck and McGeorge (2005), 
including deviations from the standards.
Measurement of Tg
Many room temperature curing (rigid) adhesives have a glass transition 
temperature (Tg) of around 50°C to 70°C. It is therefore important to estab-
lish the precise Tg in order to select a suitable temperature for accelerated 
ageing tests. These measurementsare not applicable to fl exible adhesives 
(e.g. polyurethanes) as their Tg is well below 0°C. The applicable test is the 
torsion-pendulum test according to ASTM E 1356 or ISO 6721.
 Adhesives for marine environments and pre-design 29
© Woodhead Publishing Limited, 2012
Measurement of pH value
The measurement of the pH value of all adhesives is important since experi-
ence has shown that some adhesive can be quite acidic or alkaline under 
the long-term infl uence of water. This can create corrosion problems in 
the joint. It is therefore important to select adhesives with a ‘neutral’ 
pH value. The test procedure follows the IFAM test standard WP-AA-60 
(see Weitzenböck and McGeorge, 2005 or Det Norske Veritas, 2011a).
Lap-shear test – strength
This is the most common test used for all types of adhesives. Lap-shear 
strength is measured before and after ageing to assess the ability of the 
adhesives to withstand adverse environments. The relevant test standards 
are: ASTM D 1002, DIN EN 1465, ISO 4587.
Lap-shear test – strain to failure
Flexible adhesives show creep when loaded. The aim of this test is to assess 
the ability of the adhesive to sustain strain. This test is a slightly modifi ed 
standard lap-shear test where a constant displacement (strain) is applied. 
The details of the tests are documented in Det Norske Veritas (2011a). 
An alternative based on IFAM test standard WP-AA-11 can be found in 
Weitzenböck and McGeorge (2005).
Boeing wedge test
The Boeing wedge test (ASTM D 3762) can be used to assess the durability 
of the bonding system – the complete surface preparation and coating and 
the adhesive. This test is only used for rigid adhesives.
Measurement of electrical resistance
The measurement of electrical resistance of all adhesives is important to 
make sure that all selected adhesives have suffi cient specifi c resistance. This 
will ensure that the adhesive layer acts as electrical insulator and prevents 
electrochemical corrosion not only at the joint but anywhere in the structure. 
The applicable test procedure is the Sika Test Procedure 316 ‘Determination 
of electrical specifi c volume resistance’ (Weitzenböck and McGeorge, 2005).
Bead test
The bead test (Sika SQP033-0, Sika SQP034-0; see also Weitzenböck and 
McGeorge, 2005) was selected to assess the durability of the bonding system 
30 Adhesives in marine engineering
© Woodhead Publishing Limited, 2012
– the complete surface preparation and coating and the adhesive. This test 
is only used for fl exible adhesives.
2.6 Adhesive selection step 4: 
seek supporting information
Ashby proposes that the last step in the selection process is dedicated to 
researching the history and experience with the top-ranked material and 
process. Reuter (2007) suggests that rather than simply seeking supporting 
information, one uses ‘verifi cation’ of the material selection as the fi nal step. 
This can be based partly on a risk analysis such as Fault-Tree Analysis or 
FMEA (Failure Mode and Effect Analysis) and mostly on verifi cation by 
calculation and or rapid prototyping and or testing of the selected material 
or a bonded assembly. Several chapters in this book are concerned with 
detailed analysis and testing of bonded connections and structures.
In many marine applications the use of adhesive bonding is quite new. 
Most of the established criteria and test and analysis methods are not suit-
able to assess whether the bonded connection is acceptable or not as they 
were designed with other joining methods in mind. Hence the verifi cation 
activity needs to demonstrate that adhesive bonding is at least as safe as 
traditional solutions. This could be done using a risk-based approach, such 
as the ‘Qualifi cation of new technology’ process described in Det Norske 
Veritas (2011b).
2.6.1 Simplifi ed approach
In certain situations it is quite possible to shorten the selection process. 
Having said that, the fi rst step – translating design requirements – is essen-
tial to successful adhesive joining. It is here that structural and fabrication 
requirements are translated to adhesive specifi c requirements. However, 
the other steps may be modifi ed or simplifi ed as shown for example for 
elastic bonding by Burchardt et al. (1998). The authors suggest a simplifi ed 
selection process as most fl exible adhesives have quite similar mechanical 
properties. Burchardt et al. select (fl exible) adhesives according to only two 
criteria: (i) compatibility with the materials to be joined and (ii) cost – 
simple and economical to apply. Moreover, they emphasise the importance 
of good process and quality control. Sometime additional criteria are used 
such as non-sag and high early strength during cure.
2.7 Future trends
As mentioned in the introduction, adhesive bonding is still a relatively 
young joining method in marine engineering with many research and 
 Adhesives for marine environments and pre-design 31
© Woodhead Publishing Limited, 2012
development opportunities. However, this does not preclude it from being 
used today, albeit for less demanding applications. However, to make 
adhesive bonding more attractive as an industrial process, one needs 
to remove as many potential barriers as possible. In particular there 
is a need for standard solutions that are pre-qualifi ed and pre-approved. 
Usually there is no time to develop and qualify new designs, hence the 
need for off-the-shelf technology. Another important area is the integration 
of adhesive bonding in Finite Element Analysis (FEA) and Computer 
Aided Design (CAD) software. Modern ships and offshore structures 
are designed and analysed using advanced FEA and CAD systems. 
Hence, adhesives and the adhesive bonding process needs to be character-
ised suffi ciently to be able to model them in these systems. Arenas and 
Guillamón (2007) present a solution on how to represent adhesive bonding 
in design software. These developments will lead to a signifi cant decline in 
the need for adhesive selection. Pre-approved standard solutions may be 
selected from catalogues or standards including material and process speci-
fi cations. However, more demanding applications still require ‘adhesive 
selection’.
While there is clearly need for industry wide standard solutions, Reuter 
points out that this at the same time might hamper development of novel 
solutions or solutions to non-standard problems (Reuter, 2007). Another 
observation is that adhesives are today mainly considered late in a construc-
tion project; usually because the original solution did not work. Hence, 
adhesive selection will have to be carried out when most parameters have 
already been fi xed – with few degrees of freedom. This is not an ideal situ-
ation but not uncommon. Adhesive specifi c designs will become more 
common in the future.
2.8 Sources of further information
Useful textbooks for adhesive selection are listed below.
 Michael Ashby is the materials selection ‘guru’. In his book, Ashby 
(2007) provides a systematic approach to selecting materials and fabri-
cation processes with many good examples (and his software).
 Reuter (2007) presents the Ashby approach in the context of engineer-
ing design and analysis (in German).
 Weitzenböck and McGeorge (2005) offer a pragmatic approach to mate-
rial selection with emphasis on specifi cation of requirements for design, 
fabrication and use of the new product.
 Sharpe (1990) discusses adhesive selection. His chapter is part of one of 
the most comprehensive books on adhesive technology; it covers every-
thing from chemistry to engineering.
32 Adhesives in marine engineering
© Woodhead Publishing Limited, 2012
 The book by Adams et al. (1997) is one of the leading text books on 
adhesive design and analysis, with a good chapter on adhesive