ZRC Worldwide | Blog

Using ZRC® Cold Galvanizing Compound: A Solution for Out-of-Spec Galvanized Metal

Written by Sam Steele | Feb 8, 2022 1:00:00 PM

You have a problem. The galvanized metal part you trusted would be delivered to your job site showed up out of spec; the metal did not arrive in its as-promised hot-dip galvanized state. As a general contractor, you have a few options: you can send the metal back to your supplier and wait for a return shipment. While your project stagnates, you can try to source another galvanized metal, or you can use ZRC® Cold Galvanizing Compound as an on-site solution.

Discover more about

  • Solutions to out of specification galvanized metal fabrication
  • What is a Cold Galvanizing Compound
  • Application types
  • Next steps for your project
  • Locating a dealer and same-day shipping

Solutions to Out of Specification Galvanized Metal Fabrication

Once you've realized the mistake in your received materials, you can't waste time pointing fingers. There will be plenty of time to assess blame and rectify your purchase orders, but right now, you need a solution that will keep your project timeline intact without breaking your budget. That means keeping your crews on-site and making progress.

ZRC® Cold Galvanizing Compound can be applied to fabricated metal on-site, with appropriate surface preparation, like a paint – by aerosol spray or roll-on application.

What is a Cold Galvanizing Compound?

A cold galvanizing compound, or zinc-rich compound, has the characteristics of a paint, but it's not a paint. The biggest difference is the percentage of zinc present in the dried film of the corrosion prevention coating.

A cold galvanizing compound is a product that simulates the performance of hot-dip galvanizing. So what's the difference?

  • Hot-dip galvanizing needs to be applied in a controlled setting, like a manufacturing plant.
  • Cold galvanizing compounds can be applied on-site directly out of a can, similar to paint.

A lesser noble metal will corrode to the more noble. Zinc-rich compounds can be applied by spray or by brush (like a paint) to steel. Zinc, being less noble than steel, forms hydroxycarbonate salt when it corrodes that bonds with the existing zinc in the film coating while upholding galvanic protection. This creates an advanced, self-healing film that ensures the metal surface beneath the coating stays protected.

This zinc-rich coating, manufactured with ultra-pure ATSM D520 Type III zinc dust, is what performs to exacting standards under an ISO 9000 quality system. [Read more about Cold Galvanizing Compounds is this blog post.]

Application Types

Once applied and dried, zinc-rich coatings are designed to perform to the same industry standard of corrosion prevention whether sprayed-on or applied by brush.

Brush-on:

Brush-on applications will create a better interface between the product and the protected surface than a spray-on application will. Brushing mashes the zinc onto the surface and creates better contact between the zinc and steel.

Spray-on:

Cold galvanizing spray can be administered in aerosol form or by use of a compressor or airless spray techniques. ZRC's Cold Galvanizing Compound in aerosol yields the same superior performance as the brush-on type. ZRC simply adds propellants and other ingredients so it sprays easily and evenly out of an aerosol can. ZRC Worldwide's aerosol application method is low in VOC and yields a consistent dry film thickness not found in low-cost solutions. This does not change the performance of the product.

Dealing with a larger project that requires coating a large surface area? Consider using a compressor to apply a ZRC Cold Galvanizing Compound. [Read more about application types in this blog post.]

Next Steps for Your Project

There are a few things to consider when dealing with galvanized metal fabrication to repair components of an existing project.

When you build a structure from galvanized metal, you are making adjustments to the components of the project as you build. As you cut, weld, and bolt sections of metal within your structure, you'll need to ensure the cross-sections are galvanically protected from potential corrosion. If surface coatings get scratched during the construction process, ZRC® Cold Galvanizing Compound can help you quickly and effectively restore corrosion protection to your metal.

#1 Identify the problem

You've ordered galvanized fabricated metal, and what you've received is not galvanized.

Example from case study

ZRC Cold Galvanizing Compound has been specified and applied as a substitute for hot-dip galvanizing on two 20 x 40' steel doors at the Tampa Port Authority Transit Shed, Tampa Bay, Florida.
ZRC effectively solved the problem of providing long-term protection for the large doors in a corrosive atmosphere, while allowing the contractor to apply zinc protection to pre-manufactured doors at the job site. In order to prepare the surface of the doors, they were sandblasted to SSPC-SP-6 (Commercial Blast). ZRC was applied by conventional air spray. Two coats of epoxy were then applied as a topcoat.This resulted in a level of corrosion resistance which matches hot-dip galvanizing.

#2 Locate a solution

Talk to an expert at ZRC or utilize the Product Finder tool to determine which ZRC product best fits your needs.

ZRC Cold Galvanizing Compound At A Glance

Equivalent to hot-dip galvanizing, ZRC's Cold Galvanizing Compound is manufactured with the highest purity ASTM D520 Type III zinc dust. Meeting VOC standards in all fifty states, it passes ten-year subtropical exposure testing and exceeds ASTM A780 standards for hot-dip galvanic repair. With flexible application formats, our product is the industry standard in combating corrosion, for true galvanic protection.

Specifications:

  • SSPC Paint Specification 20 – Zinc-Rich Coating: Type II – Organic; Level 1 – equal to or greater than 95% zinc dust by weight present in the dried film.
  • ASTM D 520 Type III Zinc Dust - .002% maximum lead by weight
  • Weight per gallon – not less than 24 lbs. VOC Content — ASTM D 3960, 385 g/l (3.3 lbs per gallon) maximum
  • Color and Gloss – Matte finish, "battleship grey"

#3 Bring your team up to speed

Report your findings to the decision-makers who can help you advocate for immediate action:

      1. General Contractor
      2. The Subcontractor(s)
      3. The Architect(s)
      4. The Engineer(s)

You may also have to get approval from the project owner.

#4 Locate a dealer

Congratulations! You've successfully navigated a potential derailment of your project and have instead found a solution to help your team stay within the project timeline and avoid costly and time-consuming steps in that process.

Go With the Experts

Imitation is flattering, but the proof is in the paint. ZRC Worldwide created zinc coating technology to combat corrosion and has been a world leader in the space for 70 years. You need certified protection. ZRC® Cold Galvanizing Compound gives equivalent protection of hot-dip galvanizing when applied to at least a three mm thickness.

Purchase your ZRC® Cold Galvanizing Compound as an on-site solution for your project today, and we'll ship within 24 hours.