This document provides an overview of fibreglass (also known as GRP) as a composite material used for surface protection systems. It discusses the applications of fibreglass, the materials used to make it including glass fibres and resins, how fibreglass composites are created, and the benefits they provide as linings and coatings. These include high strength, light weight, resistance to chemicals, UV radiation, abrasion and impacts over long periods of time. Examples of fibreglass applications include storage tanks, water features, roofs and more.

1. Fibreglass (GRP)
LININGS & COATINGS
Understanding the science, performance and applications
of Fibreglass (GRP) as a surface protection system
Stephen Bowen, Managing Director, Strandek GRP Systems
WWW.STRANDEK.CO.UK

2. CONTENTS
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Ø Applications of Fibreglass (GRP)
Ø Understanding Fibreglass (GRP)
Ø Types or Resin
Ø Types of Glass Fibre
Ø The Science of Fibreglass (GRP)
Ø Fibreglass (GRP) Surface Protection
Ø Fibreglass (GRP) Linings
Ø Benefits of Fibreglass (GRP)
Ø Fibreglass (GRP) Linings & Coatings
Ø How Does Fibreglass (GRP) Perform?
Ø Summary
Ø About Strandek
Ø Contact Us

3. APPLICATIONS OF
FIBREGLASS (GRP)
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• SPACE
• CONSTRUCTION
• MARINE
• AEROSPACE
• RENEWABLES

4. Fibreglass, also known as GRP, (short for
glass reinforced polyester) is a composite
material made from both glass fibre
fragments and unsaturated polyester resin.
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Understanding Fibreglass (GRP)
What is Fibreglass (GRP)?
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One that is made by combining two or more materials,
often with very different properties. These materials
compliment each other, giving highly unique properties.
What is a composite?
Fibreglass (GRP) itself has a
high strength-to-weight ratio,
excellent long-term
waterproofing, abrasion
resistance and resistance to a
wide range of chemicals, from
acids to fuels and solvents.
“Overall, the composite components have performed better than conventional metallic structures because of reduced corrosion and fatigue problems. The
effectiveness of the fiberglass isolation pads to prevent galvanic corrosion between graphite and metal parts was 4 demonstrated.”
NASA Composite Materials Development: Lessons Learned and Future Challenges, Tenney, R., NATO Research and Technology Agency (RTA)
Glass fibre mat
Polyester resin

5. Types of Resins
Chemical Class
Material Strong acids Strong alkalis Hot/Wet Salt solution Strong oxidants Aliphatic solvents Aromatic solvents
Epoxies Medium Medium-High High High Low-Medium High High
Polyesters High Medium Low High High High High
Polyurethanes Medium Medium-High Medium Medium Medium Medium Medium
Vinyl esters Medium-High High High High High High High
Mild steel Low High Low Low Low High High
Stainless steel Low High High Low Low High High
Aluminum Low Low High Low Low High High
Comparative resistance of polymers and metals against chemical classes. H = High, M = Medium, L = Low.
Extracted from: 2.05 - Glass Fiber Reinforced Plastics—Properties
“Resins are more simple hydrocarbons units
containing a single inorganic group (nitrogen,
oxygen or sulphur) and are polar components.”
Developments in Petroleum Science, 2015
Understanding the resins used to make fibreglass composites
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Resins are used to create composites when combined with
fibre-based backing, like glass fibre. The table below shows
some of the many resins used to create composites and
compares their chemical resistance to that of various metals

6. Types of Glass Fibre
Glass fibre type Description Density (g/cm3) Tensile strength (GPa) Young's Modulus (GPa)
E-glass Good for electrical insulation 2.54 1.7 - 3.5 69-72
S-glass
High silica, able to withstand high
temperatures
2.48 2.0 - 4.5 85
C-glass
Corrosion resistant 2.48
1.7 - 2.8
70
Alkali-resistant glass fibre is considered Cemfil. 2.7 80
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Understanding the glass fibre used to create fibreglass composites
Glass fibres (chopped strand) are frequently used as reinforcement in
thermoplastics.
They are cost-effective, and a broad range of physical properties can
be achieved for many applications.
Glass fibre reinforcements are strands of filaments drawn to different
diameters between 3.8 and 18 μm.
Tribology and Interface Engineering Series, 2008
Glass fibre mat
The table below presents some of the types of glass fibres used to create composites and their physical properties

7. Following application and over a period of several hours, the resin hardens or ‘cures’, catalysed by an organic peroxide inhibitor. This polymerization, where
connections (cross-linked bonds) form between each molecule. Individually these bonds are weak, but collectively they are incredibly strong. See more
about how to create a create a (GRP) lining and coating system.
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The Science of Fibreglass (GRP)
Polyester resin cross-linking
+
The polymerization of unsaturated polyester resin is very well characterised. Long-chain unsaturated polyester resin molecules contain double bonds
(ethylenic groups) and ester groups. Because of these double bonds they are often classified as vinyls. Curing is facilitated by cross-linking long linear
chains using vinyl monomers such as styrene. Incorporating an organic peroxide catalyst prior to use.

8. 2 – 4 microns
RESIN
GLASS FIBRE MAT GRP COMPOSITE
During preparation, unsaturated polyester resin is used to saturate strands of glass
fibre mat, removing air pockets encapsulating glass fibres. This forms a malleable
composite that can be custom moulded to almost any surface and into any shape
making it useful for a range of industrial applications. Once hardened, this shape can
be used to provide impervious structural protection for a variety of surfaces and
structures.
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The Science of Fibreglass (GRP)
Creating a fibreglass composite
2 – 4 microns
RESIN
GLASS FIBRE MAT GRP COMPOSITE
2 – 4 microns
RESIN
GLASS FIBRE MAT GRP COMPOSITE
+

9. Linings and coatings are protective materials for surfaces, substrates and their respective structures, designed
to create an impervious surface: one that is waterproof, chemically resistant, robust and durable across
extended time periods, from flat roofing systems to chemical spill bund linings.
Lining = inner barrier
Coating = outer barrier
Substrate
Liquid being contained
Top-down view of a primary containment vessel
Fibreglass (GRP) Surface Protection
A high-performance lining & coating system
Coating: a thin layer or covering of an external surface. The
primary purpose is to prevent external contaminants entering the
structure and in some cases exiting. A secondary objective is to
also act as a means to prevent internal material from leaking
outwards in the event of a leak.
Lining: a layer of different material that covers the inside surface of
a structure. The purpose of a lining is to contain a liquid, gas or
solid by protecting the inner surface of the vessel or structure
through the use of a resin that is superior to the existing surface
alone in multiple ways. A standard example is a GRP lining system.
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10. WWW.STRANDEK.CO.UK
Fibreglass (GRP) Linings
Example fibreglass lining for a variety of substrates
Topcoat: coat of polyester resin with embedded non-slip grit or
anti-microbials.
Fibreglass laminate: 450 - 600 gram per square meter
Primer coat: damp-proofing and adhesion-promoting
layer that also inhibits moisture transition.
Substrate: base layer, typically concrete,
wood, GRP or certain metals. Already
Intended to be protected as it provides
structural support and adhesion for the
successive resin layers
The image below is of a fibreglass lining or coating. It comprises multiple layers on top of a
substrate, typically made from wood, concrete or certain metals. These layers are often built up
from (1) a resin primer, (2) GRP laminate made from either 450 or 600 gram per square meter and
(3) a resin topcoat.

11. “When each of the above stressors are combined, wear and breakdown is accelerated significantly
– and leaks often occur. The benefit of Strandek® fibreglass (GRP) linings and coatings, when
applied to an unprotected surface is that it can virtually eliminate these effects, prolonging the
lifetime of the underlying surface and therefore underlying structure.” Steve Bowen, MD, Strandek
Benefits of Fibreglass (GRP)
Why does fibreglass offer such effective surface protection?
Fibreglass is a composite – a substance that is made by combining two or more materials, often with very different
properties. These materials are often limited alone, but compliment each other when combined, giving highly unique
properties. In the case of the structural attributes of fibreglass, it has a high strength-to-weight ratio, excellent long-term
waterproofing, abrasion resistance and resistance to a wide range of chemicals, from acids to fuels and solvents.
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UV
UV solar IceWater
Resistance
Strength
Chemical
Resistance
Decades Foot trafficHigh
temperatures

12. WWW.STRANDEK.CO.UK
Fibreglass (GRP) Linings & Coatings
Waterproofing, chemical containment and surface protection
COOLING TOWERS WATER FEATURES STORAGE TANKS
GUTTERS FLAT ROOFING CONTAINMENT BUNDS WALLS & FLOORS
GULLIES

13. If the concrete is dry, it should be scaled back and cleaned to
create a uniform surface. Some roughness to promote resin
adhesion is recommended. By removing weak and fragmented
outer layer, as well as associated dust and exposing the stronger
under layer, a surface amenable to resin bonding is created.
1. Surface preparation 2. Primer application 3. Glass fibre mat placement
4. Apply polyester resin 5. Laminate consolidation 6. Topcoat application
The resin should also be able to penetrate into a thin layer of the
concrete, thus creating ‘anchors’ once it hardens. These anchors
collectively create very strong connection to the concrete when
combined with the chemical interaction, making it perfect as a
bund wall and floor lining, gutter lining, storage tank relining,
water features and other waterproofing applications.
Fibreglass (GRP) Linings & Coatings
Fibreglass (GRP) application to concrete – one of many substrates
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14. GRP is often compared to metals like steel, aluminum and titanium – particularly from a
structural perspective because of its incredible strength. These characteristics are crucial
when considering it as a protective lining or coating system.
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How Does Fibreglass (GRP) Perform?
Physical performance versus metal…
Even NASA use fibreglass-like composites for their spacecraft….
“The lander is a strong, lightweight structure, consisting of a base and three sides "petals" in the
shape of a tetrahedron (pyramid-shaped). The Lander structure consists of beams and sheets that
are made from a "composite" material. Composites such as fiberglass are made of strong fibers or
fabrics that are stiffened with a glue, or "matrix". ”
Disclaimer: these values have been compiled from a combination of academic and online resources and should not be taken as performances attainable by Strandek GRP Systems. They may not represent the true values attainable from
these materials and should not be interpreted as such.

15. What is the cost per kg?
The price for 1 kg of GRP
relative to other materials and
substrates
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Cost (£/kg) vs. Other Substrates
Why is it important?
Enables a direct comparison
to other substrates and
materials.
How does GRP perform?
GRP is comparably priced to
other substrates and materials,
but a bit more than certain
metals like steel an aluminium.
2.34
7.15
5.07 5.2
1.95
0.325 0.65
3.51
21.125
0
5
10
15
20
25
Alum
inium
alloy
Epoxy
therm
osetGFRP
lam
inate
(glass)
Polyurethane
elastom
er
Polyvinylchloride
(rigid
PVC)
Steel,high
strength
4340
Steel,m
ild
1020
Steel,stainlessaustenitic304Titanium
alloy(6Al4V)
COST(£/KG)
2.34
7.15
5.07 5.2
1.95
0.325 0.65
3.51
21.125
0
5
10
15
20
25
Alum
inium
alloy
Epoxy
therm
osetGFRP
lam
inate
(glass)
Polyurethane
elastom
er
Polyvinylchloride
(rigid
PVC)
Steel,high
strength
4340
Steel,m
ild
1020
Steel,stainlessaustenitic304Titanium
alloy(6Al4V)
COST(£/KG)
Cheaper is
better, of course!
Source: http://web.mit.edu/course/3/3.11/www/modules/props.pdf

16. WWW.STRANDEK.CO.UK
Density (kg/m3) vs. Other Substrates
What is density?
Density is the mass per unit
volume. How much substance a
material has in a given volume.
Why is it important?
Lighter materials that also
retain their strength present
significant structural benefits.
How does GRP perform?
GRP is very light compared to
metals like steel and titanium.
With its strength it offers a very
high strength-to-weight ratio.
2.7
1.2
1.8
1.2
1.4
7.8 7.8 7.8
4.5
0
1
2
3
4
5
6
7
8
9
Alum
inium
alloy
Epoxy
therm
osetGFRP
lam
inate
(glass)
Polyurethane
elastom
er
Polyvinylchloride
(rigid
PVC)
Steel,high
strength
4340
Steel,m
ild
1020
Steel,stainlessaustenitic304Titanium
alloy(6Al4V)
DENSITY(KG/M3)
Lower densities are mostly
better… It means the
substrate is lighter.
Source: http://web.mit.edu/course/3/3.11/www/modules/props.pdf

17. WWW.STRANDEK.CO.UK
Young’s Modulus (GPa) vs. Other Substrates
What is the Young’s
modulus?
Measurement of stiffness of a
solid material – the force
needed to deform it.
Why is it important?
Defines relationship between
stress and strain in a material in
the linear elasticity regime of a
uniaxial deformation
How does GRP perform?
GRP is below metals, but above
other resins and polymers. Its
precise benefit depends on its
application.
70
3.5
26
0.025 1.5
210 210 210
100
0
50
100
150
200
250
Alum
inium
alloy
Epoxy
therm
osetGFRP
lam
inate
(glass)
Polyurethane
elastom
er
Polyvinylchloride
(rigid
PVC)
Steel,high
strength
4340
Steel,m
ild
1020
Steel,stainlessaustenitic304Titanium
alloy(6Al4V)
YOUNG'SMODULUS(GPA)
High = stiff
Source: http://web.mit.edu/course/3/3.11/www/modules/props.pdf
Low = flexible

18. WWW.STRANDEK.CO.UK
Shear Modulus (GPa) vs. Other Substrates
What is the Shear
Modulus?
The ratio between shear
stress and shear strain.
Why is it important?
Describes the elastic properties
of a solid under the application
of transverse internal forces
How does GRP perform?
GRP is more flexible than
metals – especially steel, but
much more rigid than
polyurethane resin.
28
1.4
10
0.0086 0.6
76 76 76
39
0
10
20
30
40
50
60
70
80
Alum
inium
alloy
Epoxy
therm
osetGFRP
lam
inate
(glass)
Polyurethane
elastom
er
Polyvinylchloride
(rigid
PVC)
Steel,high
strength
4340
Steel,m
ild
1020
Steel,stainlessaustenitic304Titanium
alloy(6Al4V)
SHEARMODULUS(GPA)
Source: http://web.mit.edu/course/3/3.11/www/modules/props.pdf
High = stiff
Low = flexible

19. WWW.STRANDEK.CO.UK
Poisson’s Ratio (N) vs. Other Substrates
What is the Poisson’s
Ratio?
Ratio of transverse contraction strain
to longitudinal extension strain in the
direction of a stretching force.
Why is it important?
Ratio of change in width / unit
width of a material to the
change in its length per unit
length due to strain.
How does GRP
perform?
GRP is similar to most
metals and other polymers.
0.34
0.25
0.28
0.5
0.42
0.29 0.29 0.28
0.36
0
0.1
0.2
0.3
0.4
0.5
0.6
Alum
inium
alloy
Epoxy
therm
osetGFRP
lam
inate
(glass)
Polyurethane
elastom
er
Polyvinylchloride
(rigid
PVC)
Steel,high
strength
4340
Steel,m
ild
1020
Steel,stainlessaustenitic304Titanium
alloy(6Al4V)
POISSON'SRATIO(N)
Source: http://web.mit.edu/course/3/3.11/www/modules/props.pdf
High = lateral
strain is higher
Low = longitudinal
strain is higher

20. WWW.STRANDEK.CO.UK
Yield Stress (MPa) vs. Other Substrates
What is the Yield Stress?
Value of stress at a yield point
or at the yield strength.
Why is it important?
Indicates the amounts of stress
that an object needs to
experience for it to be
permanentaly deformed.
How does GRP perform?
GRP is superior to other
resins and comparable to
certain types of steel.
500
45
125
30 53
1240
200
240
910
0
200
400
600
800
1000
1200
1400
Alum
inium
alloy
Epoxy
therm
osetGFRP
lam
inate
(glass)
Polyurethane
elastom
er
Polyvinylchloride
(rigid
PVC)
Steel,high
strength
4340
Steel,m
ild
1020
Steel,stainlessaustenitic304Titanium
alloy(6Al4V)
YIELDSTRESS(MPA
Source: http://web.mit.edu/course/3/3.11/www/modules/props.pdf
High = resistant
to breaking

21. WWW.STRANDEK.CO.UK
Fracture Toughness (MN M-3/2) vs. Other Substrates
What is Fracture Toughness?
Quantitative way to express
material’s resistance to crack
propagation.
Why is it important?
Indicates ability of a material
containing a crack to resist
fracture.
How does GRP perform?
GRP is superior to most
polymers and even aluminum,
but is surpassed by steel and
titanium.
28
0.5
40
0.3 0.54
100
140
50
85
0
20
40
60
80
100
120
140
160
Alum
inium
alloy
Epoxy
therm
osetGFRP
lam
inate
(glass)
Polyurethane
elastom
er
Polyvinylchloride
(rigid
PVC)
Steel,high
strength
4340
Steel,m
ild
1020
Steel,stainlessaustenitic304Titanium
alloy(6Al4V)
FRACTURETOUGHNESS(KC,MNM-3/2)
A higher fracture
toughness is better
Source: http://web.mit.edu/course/3/3.11/www/modules/props.pdf

22. WWW.STRANDEK.CO.UK
Thermal Expansion (10-6/C) vs. Other Substrates
What is Thermal Expansion?
Tendency for a material to
change its shape, area and
volume due to temperature
change.
Why is it important?
Indicates its capacity for
physical change in response
to temperature.
How does GRP perform?
GRP is more susceptible to
change than certain polymers,
but better than all steels and
titanium.
33
60
19
125
75
14 14
17
9.4
0
20
40
60
80
100
120
140
Alum
inium
alloy
Epoxy
therm
osetGFRP
lam
inate
(glass)
Polyurethane
elastom
er
Polyvinylchloride
(rigid
PVC)
Steel,high
strength
4340
Steel,m
ild
1020
Steel,stainlessaustenitic304Titanium
alloy(6Al4V)
THERMALEXPANSION(10-6/C)
More sensitive
to temperature
Source: http://web.mit.edu/course/3/3.11/www/modules/props.pdf

23. • in most cases significantly cheaper than metals
• both flexible and as strong as certain metals
• exceptionally light (much lighter than metals) and slightly heavier than wood
• an all-round, high-performance and low-cost protective lining & coating
• durable and robust, with lifetimes as high as 50 years
• preferred by many industries, from construction to processing, marine an aerospace industries
Disclaimer: these values have been compiled from a combination of academic and online resources and should not be taken as performances attainable by Strandek GRP Systems. They may not represent
the true values attainable from these materials and should not be interpreted as such.
Summary
Fibreglass GRP linings & coatings are:
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24. History
• Founded in 1976
• Specialists in cold-applied, resin-based linings and coatings, from fibreglass (GRP) to epoxy and polyurethane
Responsibility
• A strong health, safety & environmental policy
• Trained, certified and dedicated applicators
Service & Performance
• Experts in a range of resin-based composites, from fibreglass to polyurethanes and epoxies.
• Close working relationship with leading manufacturers
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About Strandek®
Experts in surface waterproofing and chemical protection

25. Contact Us
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Steve Bowen
Managing Director & Founder
Phone: 01633 250652
Email: steve.bowen@strandek.co.uk
Paul Chapman
Senior Manager
Phone: 02920 900011
Email: paul.chapman@strandek.co.uk
Main Address
Strandek GRP Systems
Croes-Carn-Einon, Newport
South Wales, NP10 8RR
www.strandek.co.uk
Company number: 01448607
Jan Pitt
Finance & Administration
Phone: 01633 250652
Email: admin@strandek.co.uk