By Dan Davis
Adiscussion of industrial coatings for many metal fabricators would be as interesting as watching paint dry.
Most shops aren’t involved in any sort of finishing.
If something requires paint, they send it off to a custom coater. For those fabricators that do run paint
lines or batch operations, they likely don’t focus on
it like they do on their fabrication operations. After
all, painting is a value-added activity. They are paid
mostly for their fabricating knowledge. The paint
line keeps some customers happy because they are
dealing with only one vendor when questions arise
about part and finish quality.
Even if coating is not a core competency for a
metal fabricator, the company is better off knowing
about advancements in protective coatings tech-
nology. It can mean a big difference in possibly de-
livering a better final product to the customer while
pocketing some production-related savings simul-
The FABRICATOR engaged three coatings experts
to find out just what is happening with material developments and what they mean to metal fabricators that have to paint products.
The FABRICATOR: In what ways have coatings
evolved over the past several years to deliver improved corrosion resistance?
Chet Dinkins, industry sales manager, Sumter
Coatings Inc.: The concern over volatile organic
compounds is driving people to use more water-
based coatings and coatings with less solvent. That
has really taken precedence over improving coat-
ings. So much time and research have been spent
on trying to make coatings environmentally friendly
to meet regulations. So a lot of the lab time is spent
doing that rather than coming out with coatings
that may be a lot better.
Having said that, today’s coatings have improved
somewhat. In my opinion, they could have improved more with more research being done in the
area of corrosion resistance versus trying to find
something that is friendlier for the environment.
Terry Welch, president, Prime Coatings Co.: There
has been tremendous advances in waterborne
chemistry with better corrosion resistance than in
the past. So there are more options there.
We have seen advances in UV chemistry for UV
coatings [in which the coatings are cured when exposed to UV light], especially for temperature-sen-sitive substrates. The curing temperatures are just
too high. We have seen tremendous advances in UV
coatings for metal.
I would say those are the biggest trends that
FAB: Has the variability in materials, such as the
emergence of high-strength steels and advanced
aluminums, posed a challenge to coatings makers?
Steve Dickey, senior director, global product
strategy, Sherwin-Williams Protective & Marine
Coatings: No, we have coatings for all types of metals and environments. It is really just a matter of
matching the correct coating to the specified metal
and the expected environment.
Welch: I don’t think so. I think with most of those
types of substrates, adhesion is not a problem.
FAB: In what ways have water-based coatings
achieved a performance level that more traditional
solventborne coatings used to deliver?
Dinkins: Waterbornes have improved, but they are
still not, in my opinion, where the solvent-based,
traditional coatings have been. But they are getting
Welch: We have corrosion-resistant primers that
work well. There are good baking systems. We have
acrylic melamine resins that work really well. We
have emulsions. We have water reducible paints.
There are a number of tools that you can throw at
a given problem compared to the past, when you
were limited to just [solventborne] materials. For
example, we are making air-dry waterbornes with
excellent UV resistance, adhesion, and flexibility.
The type of coating that still might be a challenge
for waterbornes would be a very high-gloss, wet-looking clearcoat, such as the final clearcoat for an
auto or a motorcycle. We don’t have a waterborne,
nor does anyone else, that will give you a super-high
gloss, wet-clearcoat look. So we are still using two-coat polyurethanes mainly for that, as well as enamels and lacquers.
FAB: What is the state of solventborne coatings in
today’s environmentally conscious world?
Fabricators with painting operations should be aware
of advances in paint makeup that can lead to stronger
corrosion protection and lower application costs