Painting Over Hot Dip Galvanized Steel

A common challenge in working with HVAC ductwork is painting galvanized steel pieces. Whether the reason is corrosion protection or architectural design, the challenge is the same.

At ZEN Industries, we know a fine end result can be achieved if proper procedure is followed; however, if corners are cut or improper techniques employed, the result can be poor adhesion of paint and a sub-standard product.

Let’s start by sharing an article prepared by the American Galvanizers Association: Painting Over Hot Dip Galvanized Steel. This detailed, six page article reviews procedures for painting duplex systems and will be of interest to anyone who has faced the challenge of painting over HDG Steel, regardless of whether the pieces involved are HVAC ductwork, galvanized steel poles, or building piping, etc.

Ensuring Proper Procedure

Following proper procedure for coating hot dip galvanized steel is imperative if a quality final product is desired.

According to this article on Galvanizeit.org , the proper steps to be taken involve:

• Communication – There must be communication between all parties involved to ensure special handling procedures are met and that everyone is aware of the conditions of each part.
• Assess Surface Condition – Determine whether any preliminary cleaning and additional surface preparation procedures need to be taken.
• Surface Cleaning - Remove any dirt, grease, and oils, while making sure not to remove too much of the galvanized coating.
• Surface Profiling – A multitude of different methods can be taken to properly profile the surface for improved adhesion.
• Painting - Consult your paint manufacturer for the proper paint selection.

With proper practice, a long-lasting, durable coating can be applied to hot dip galvanized steel despite the many difficulties presented in attempting to paint such a surface.

Galvannealed (Paint Grip) HVAC Ductwork

ZEN Industries is an experienced fabricator of galvannealed HVAC ductwork.

Hot-dip galvanizing results in a very fine gray matte finish. Galvanneal does not flake when formed, stamped, and bent, and the finish acts like a primer to allow good paint adhesion.

Rust proof, galvannealed HVAC duct is paintable, weldable, and corrosion resistant.

Contractor Alert!

Some Low VOC Paints Adhere Poorly to Galvanneal (Paint Grip).
Today, many applications call for low VOC paint products. Schools, hospitals, LEED projects, and green developments require paint low in volatile organic compounds.

Unfortunately, some of these low VOC paints have been problematic in working with Galvanneal (paint grip) ductwork. Though counterintuitive, low VOC paints often work better on traditional galvanized steel products.

To learn more, contact ZEN Industries today.

Piping and HDG Steel

Piping is no different if it has been hot dip galvanized.

Where decorative or functional piping is exposed as an architectural element, the same problems and challenges exist.

At ZEN industries, we have experience in fabrication and welding of heavy gauge steel duct and piping.

Visit our Specialty Ductwork and Welded Duct page to learn more.

When it comes to working with HVAC and piping installations, did you know ZEN MEP can assist with estimating and duct drawings? Our proven 21st century methods can help bring any construction project in on-time and under-budget.

And, of course, call on us for all of your spiral and rectangular duct needs. Fast quotes, fast turnaround, and affordable prices are the hallmark of ZEN Industries service.

No matter how big or small your project:

No matter how demanding the project, ZEN Industries has the experience and expertise you need. To learn more, Contact ZEN Industries today!

ZEN Industries provides all or part of your HVAC needs. HVAC ductwork manufactured according to your schedule, meeting 3rd Edition 2005 SMACNA standards. Contact Patrick Jovanovic - Sales & Estimating at 877-600-0274.

Success in our business is about service.

Success in our business is about service. The quality of our HVAC duct work is of the highest caliber and our price competitive with the best in the industry. Nonetheless, quality and price are default items today in sheet metal fabrication. They give us access to the playing field. Service is where ZEN Industries Inc. gains its edge, and service means people - it's about our experienced personnel and the relationships we build with each and every customer.

Learn more at www.zenindustries.com

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