Wednesday, August 21, 2013

Duplex Systems

We have posted about the benefits of duplex systems many
times in this blog.  Being a galvanizer and powder coater,
we strongly encourage this type of system for many 
different types of projects.  But don't just take our word
for it, consider the opinion of Melissa Lindsley, the 
Marketing Director at the American Galvanizers Association.
Below is an article she authored, which was published in the 
August, 2013 issue of The Construction Specifier.  After 
reading the article, please give us a shout if you have any

Tuesday, July 30, 2013

New Kettle!

A message regarding the galvanizing portion of our operation:

Hubbell Galvanizing would like to formally announce that our
new kettle is now operational.  The new kettle dimensions
are as follows:

46'L x 5'W x 10'D

Please contact us with any questions regarding size/fit, or to 
place your next order -- we look forward to assisting you!

Hubbell Galvanizing
(315) 736-8311

Monday, May 20, 2013

Duplex System Compatibility

What Paints and Powders are compatible with Galvanizing?

A partial listing of available paint, paint systems,
and powder coatings that are compatible with
galvanizing are listed in the following table. The
paint manufacturer can provide more thorough
information about the compatibility of specific
systems with galvanized steel. Always consult
the paint manufacturer prior to painting galvanized
steel. Different physical and chemical characteristics
for the same types of paint may have varied reactions
with a galvanized surface. The paint manufacturer and
galvanizer can assist in the creation of a successful
duplex system.

If the pH of the paint is high, 
problems may occur due to
ammonia reacting with zinc
Aliphatic Polyurethanes
If used as a top coat for a 
polyamide epoxy primer, it
is considered a superior
duplex system
The alkaline zinc surface causes
the alkyds to saponify, causing 
premature peeling
Petroleum base is usually not
recommended for use on
galvanized steel
Used for parts that are to be
buried in soil
Chlorinated Rubbers
High VOC content has severely
limited their availability
Coal Tar Epoxies
Rarely used, only if parts are to
be buried in soil
If paint is specifically
manufactured for use with
galvanized steel
Epoxy-Polyamide Cured
Has superior adherence to
galvanized steel
Has the added benefit of being
environmentally friendly
Consult paint manufacturer
Oil Base
Consult paint manufacturer
Portland Cement in Oil
Has superior adherence to
galvanized steel
Not for use directly over 
galvanized steel, can be
beneficial in high temperature
systems w/ base coat
Usually requires profiling, high
VOC’s have severely limited
their availability
Powder Coating
Low temperature curing powder
coatings work exceptionally 
well over galvanized steel

Tuesday, April 9, 2013


Before deciding how to protect steel from
corrosion, it is important to understand how steel
corrodes. Corrosion takes place because of
differences in electrical potential between small
areas on the steel surface that become anodic and
cathodic. When an electrolyte connects the anodes
to the cathodes, a corrosion cell is created.
Moisture in the air forming condensation on the
steel surface is the most common electrolyte. In
the electrolyte, a small electrical current begins to
flow. The iron ions produced at the anode
combine with the environment to form the loose,
flaky iron oxide known as rust.
In order to protect steel from corrosion,
something must interfere with the corrosion cell,
either by blocking the electrolyte or by becoming
the anode. Two common methods of corrosion
protection are cathodic protection (the formation
of another anode) and barrier protection (blocking
the electrolyte from the steel surface). Hot-dip
galvanizing alone affords both types of protection,
and painting or powder coating over hot-dip galvanizing
adds an additional barrier layer on top of the zinc coating,
thus enhancing the protection afforded to the steel.  Duplex
coatings also offer the element of color to your project,
making it more aesthetically pleasing.

Fortress Fusion Coatings specializes in duplex coatings,
specifically in powder coating over galvanizing.  We
would be happy to discuss your project with you and
answer any questions you may have.

Fortress Fusion Coatings, Inc.
(315) 736-8311

Wednesday, March 13, 2013

Galvanizing Post Treatments & Paint/Powder Adhesion

Poor adhesion of paint or powder coating to galvanized
parts is a common issue - but it doesn't need to be.
There are a few factors that affect the adhesion between
the surfaces. One of these factors is the post-treatment of 
the galvanized steel.

After a piece of steel has been galvanized,
it is sometimes quenched or treated by the
galvanizer, in order to halt the reaction
between the iron and zinc (and to facilitate
immediate shipment of the galvanized steel).
The most common post-treatments are
water quenching and chromate quenching,

Both quenching methods (water and
chromate) can adversely affect the
bond between the galvanized steel
and the paint or powder coating, causing
adhesion issues. Communicating with the
galvanizer prior to galvanizing helps avoid
post-treatments that can be detrimental to
paint or powder adhesion.

At Fortress Fusion Coatings, we are very familiar with the factors affecting proper
adhesion between galvanized steel and paint or powder coating.  If you have any
questions about this, or any other coating-related issue, we would be happy to
discuss it with you.  Please give us a call:

(315) 736-8311 - Office
(800) 244-4258 - Toll-free
(315) 736-0381 - Fax

Friday, February 8, 2013


Duplex systems, as we define them, are materials that
have been painted or powder coated after galvanizing.

Each individual project raises unique reasons as
to why a duplex system should be utilized, and the
advantages for choosing to do so are many:

Extended Corrosion Resistance

The most obvious and most important reason for
using a duplex system, is the added corrosion
protection it provides. Other systems
simply can't match the corrosion resistance
provided by painting or powder coating
over hot-dip galvanized steel.

Synergistic Effect

It’s typical for a duplex system to provide
corrosion protection 1.5-2.5 times longer than
the sum of the lifetime of zinc or paint, used
individually.  For example, if a galvanized coating
is expected to be maintenance-free for 40 years
and a paint system is expected to last ten years,
galvanizing and paint combined should protect the
steel substrate for at least 75 years, or 1.5 times the
sum of both systems.

Economic Benefit

Because duplex systems greatly extend the
service life of a product, maintenance costs are
significantly decreased.  Additionally, a product
lasts longer before it must be replaced, thus
decreasing the life-cycle cost. The cost of a
product that has been protected by galvanizing and
painting or powder coating, is lower over the entire
life of the product than most single system methods
of corrosion protection.

Ease of Repainting

As the paint film weathers, the zinc in the
galvanized coating is present to provide both
cathodic and barrier protection, until the structure
is repainted. The exposed zinc surface then can
be repainted with minimal surface preparation.


Galvanizing has an attractive metallic-gray
appearance, suitable for a myriad of applications,
but painting or powder coating can offer aesthetic
advantages. One might choose to paint over a
galvanized coating so that a project matches its
specific environment—such as a stadium, theme
park, or natural habitat.

Safety Marking

A duplex system of galvanized
steel and paint or powder coating
may be used to conform to safety
regulations. For example, the Federal
Aviation Administration (FAA)
requires structures over 200 feet
tall to be painted in the alternating
pattern of white and orange.

Color Coding

Painting or powder coating over galvanized steel
also increases safety in many environments, by
color-coding gas, steam, or chemical pipes,
identifying hazardous work areas and walkways,
and marking high-voltage electrical lines and

Extending the Life of Previously Galvanized Steel

Paint is a logical choice to extend the life of
galvanized structures, once the zinc coating has
substantially and naturally weathered away.
Instead of being completely replaced, the
galvanized structure can easily be painted,
extending its useful life. Organic zinc-rich paints
are specifically suited to this application.

Repair of Hot-dip Galvanized Steel

Zinc-rich paints can also be used to touch-up and
repair damaged areas on a galvanized coating, in
order to comply with ASTM A 780, Repair of
Damaged and Uncoated Areas of Hot-Dip
Galvanized Coatings. Repairing a galvanized
coating will significantly extend the useful life of
a product.

Friday, March 23, 2012

DUPLEX SYSTEMS: Powder coating or Painting Over Hot-dip Galvanized Steel

For years, protecting steel from corrosion
typically involved either the use of hot-dip
galvanizing or some type of paint system.
However, more and more corrosion specialists
are utilizing both methods of corrosion
protection in what is commonly referred to as a
duplex system. A duplex system is simply
painting or powder coating steel that has been
hot-dip galvanized after fabrication. When paint
and hot-dip galvanizing are used together, the
corrosion protection is superior to either
protection system used alone.
Painting galvanized steel requires careful
preparation and a good understanding of both
painting and galvanizing. Many products have
been galvanized and painted successfully for
decades; two examples are automobiles and radio
towers. Past experience provides excellent
historical data for how best to achieve good paint
adhesion. Studying past adhesion failures and
successes led galvanizers, paint companies,
researchers, paint contractors, and other sources to
create ASTM specification D 6386, Preparation of
Zinc (Hot-Dip Galvanized) Coated Iron and Steel
Product and Hardware Surfaces for Painting.
When the galvanized surface is prepared correctly,
paint adhesion is excellent and the duplex system
becomes a highly successful method of corrosion