Corrosion Control
this. All these products and technologies are always coupled
with expert technical service.”
PPG Protective & Marine Coatings is widely recognized as
a world leader in protective and marine coatings, developing
innovative products that are designed to deliver value and pro-
tection of its customers’ assets. “PPG offers coatings solutions
in all three key categories including Barrier Coatings, Sacrificial
Coatings and Inhibitive Coatings,” said a spokesperson at PPG.
When choosing a corrosion control stytem, customers need
to consider their specific requirements.
“There are many anticorrosive systems employed to afford
the protection against corrosion – it really does depend upon
the lifetime requirements of the asset owner,” said Neil Wilds,
technical manager, Protective Coatings at AkzoNobel. “Many
major oil companies now ask for coatings to be prequalified.
This process involves the testing of coating systems to stringent
international anticorrosion standards such as ISO 20340, for
example. Only when they pass these tests will they be allowed
on certain assets. Typical coating systems could be inorganic
zinc-rich primers as part of a coating system, organic zinc-rich
primers as part of a coating system, aluminium pure epoxies,
zinc phosphate pigmented primers as part of a coating system,
high-builds epoxies and glass flake pigmented coatings i.e.
epoxies/polyesters.”
“There are also lots of other criteria, not just corrosion
protection that form part of the process,” Wilds added. “In
some cases, abrasion resistance or resistance to chemicals is
also required.”
Choosing the correct corrosion protection technology for
high value assets is not an easy task. There are several factors
that must be taken into account to select the appropriate corro-
sion protection coating.
“First, factors related to the substrate itself must be consid-
ered,” said Axalta’s Priore. “These include the type of metallic
substrate and its inherent susceptibility to corrosion, shape com-
plexity – curved surfaces, edges, corners, crevices, surface prepa-
ration – roughness and cleanliness – dirt, oil, grease, rust. Next,
environmental and operating conditions must be taken into ac-
count. In manufacturing, regulatory and emission requirements
can vary between jurisdictions necessitating the selection of
compliant systems. In use, exposure to harsh conditions such as
temperature, corrosive liquids and gases and mechanical wear
and their duration will guide the coating choice.”
“Finally, customer specific attributes play a critical role,”
he concluded. “These can include cost, color, and ease of
application. The related durability requirements/warranties
with respect to structural integrity and color/gloss retention
are also a factor.”
Another key consideration is the added value the corrosion
sytem brings to the table. “Any good coating should add value
to the customer’s business, whether this is a reduction in long-
term maintenance, increased production speeds, lower VOCs,
reduced energy use or improved hygiene,” said Tarve. “This
value-add should be one of the main considerations, as it often
leads to a higher long-term return on investment.”
In general, Tarve said, the main factors to consider are the
external or internal environment in which the structure or
equipment is operating in, as this environment is what causes
corrosion; the substrate that needs to be protected; the surface
preparation that is possible; the desired life expectancy and
maintenance requirements of the system; the required appli-
cation techniques, temperatures and equipment; and health &
safety and legislation on the application site as well as the site
where the structure or equipment will be used.
“Our sales teams guide customers through the selection
process to ensure they choose the best coating for the project,”
Tarve explained. “Also, as application is so important, we have
more than 600 NACE/FROSIO certified coating advisors on
hand to help and advise customers during application.”
Substrate Preparation is Key
Surface preparation and application are crucial to getting the
best performance from a paint system and should be performed
correctly. “A higher-end coating will not perform as expected if
these two are not in place,” said Tarve. “However, a low perfor-
mance system will deliver higher than average performance with
a high standard of surface preparation and application.”
It is extremely important for the coatings to last the lifetimes
that are being asked by customers. “There is little point spend-
ing a lot of money on a coating system if the surface prepara-
tion is substandard – it will just lead to early failure and then
costly maintenance,” said Wilds. “The cost to re-apply a coating
system offshore can be 10-15 times that of the cost in a painting
shop onshore.”
For optimal performance, both the liquid coating system se-
lection and the surface preparation must work hand in hand.
“However, in some cases, a customer’s processes may not result
in optimal substrate cleanliness and profile,” said Axalta’s prod-
uct director for its liquid coatings business, Marko Strukelj. “In
these instances, appropriate coating system selection can help
to offset the non-ideal conditions as much as possible. The cost
of the entire coating system and the expected durability can be
negatively affected by substrate surface preparation. There are,
however, other options to be considered that may help improve
performance, like applying thicker layers of coating and/or us-
ing high quality paint products such as Corlar undercoat and
Imron topcoat.”
When selecting a coatings solution for corrosion protection,
priority is placed on the substrate and its environment. “PPG
is highly skilled at crafting product solutions to provide protec-
tion in the harshest environments which may require chemical
or moisture protection,” a spokersperson for PPG said. “Our
highly trained and dedicated team of sales and technical rep-
resentatives will evaluate these needs and create a customized
coatings solution that will exceed the customer’s expectations. “
Customers expect productive and user-friendly coating
systems. “Many are sensitive to the environmental impact
of their operations and prefer reduced volatiles and minimal
waste from the products that they use,” said Strukelj. “They
also expect efficient surface coverage, good coating thickness,
