Your partner for modern and sustainable hot-dip galvanizing technology

𝐆𝐚𝐥𝐯𝐚𝐧𝐢𝐳𝐢𝐧𝐠 𝐏𝐫𝐨𝐜𝐞𝐬𝐬 𝐈𝐧𝐬𝐢𝐠𝐡𝐭𝐬 by Herwig GmbH
𝑃𝑖𝑚𝑝𝑙𝑒𝑠 - Thermomodules at K𝑜𝑟𝑘 𝑖𝑛 𝑔𝑎𝑙𝑣𝑎𝑛𝑖𝑧𝑖𝑛𝑔

Start of the week.
The morning shift began preparing everything for the scheduled production run at full capacity.

The first jig came in and went into the zinc bath. A few pimples appeared here and there.
The second jig arrived. More pimples—it’s getting worse.
The third jig—not a single piece will be accepted; the defect is too severe!
Production comes to a halt. What changed to cause this?

Pimples, sometimes also called floating dross, can appear suddenly and disappear just as quickly; yet, the real challenge begins when they become part of daily production rather than just an isolated incident.

Several factors can contribute to or intensify this galvanizing defect:

• Zinc bath chemistry, specifically iron content•
Working temperature and heating control•
Aluminum and nickel
concentrations• Melting of zinc and
alloys• Iron in the flux, salt balance, and
drying• Ash and dross
management• Skimming practices•
Material geometry

Pimples result from the interaction of pretreatment, zinc bath conditions, and process operations, and are rarely the problem in and of themselves. They are a symptom of something in the process that has deviated from its optimal operating conditions.

𝐻𝑒𝑟𝑤𝑖𝑔 𝐺𝑚𝑏𝐻 𝑠𝑢𝑝𝑝𝑜𝑟𝑡𝑠 𝑡ℎ𝑒 ℎ𝑜𝑡 𝑑𝑖𝑝 𝑔𝑎𝑙𝑣𝑎𝑛𝑖𝑧𝑖𝑛𝑔 𝑖𝑛𝑑𝑢𝑠𝑡𝑟𝑦 𝑤𝑖𝑡ℎ 𝑙𝑜𝑛𝑔-𝑡𝑒𝑟𝑚 𝑔𝑙𝑜𝑏𝑎𝑙 𝑒𝑥𝑝𝑒𝑟𝑖𝑒𝑛𝑐𝑒 𝑎𝑛𝑑 𝑎 ℎ𝑎𝑛𝑑𝑠-from a variety of applications, such as𝑒 𝑐𝑜𝑚𝑝𝑙𝑒𝑡𝑒 𝑝𝑟𝑜𝑐𝑒𝑠𝑠.

Do you have a checklist of 𝒔𝒚𝒎𝒑𝒕𝒐𝒎𝒔 to evaluate when pimples start to appear? Or do you wait until they 𝒇𝒂𝒅𝒆 𝒂𝒘𝒂𝒚?

INDIAN business partners, welcome!

𝐆𝐚𝐥𝐯𝐚𝐧𝐢𝐳𝐢𝐧𝐠 𝐏𝐫𝐨𝐜𝐞𝐬𝐬 𝐈𝐧𝐬𝐢𝐠𝐡𝐭𝐬 by Herwig GmbH
𝑍𝑖𝑛𝑐 𝑡𝑜 𝑎𝑠ℎ𝑒𝑠... 𝑚𝑜𝑛𝑒𝑦 𝑡𝑜 𝑑𝑢𝑠𝑡

Ash generation in hot-dip galvanizing is inevitable, but excessive ash generation is not. The difference lies in a few critical process parameters:

• Is there dedicated drying equipment?
• Is the material properly dried before entering the zinc bath?
• Does the flux have the proper strength, and what about the ratio and iron content?
• Are the kettle operators trained and equipped to skim the zinc bath efficiently?
• How well suited is the jigging method to the material’s geometry?

Every single point listed above influences how much zinc ends up on the steel… and how much ends up as ash.

Reducing ash generation is, therefore, not about a single factor—it’s about controlling the process as a whole.

𝐻𝑒𝑟𝑤𝑖𝑔 𝐺𝑚𝑏𝐻 𝑠𝑢𝑝𝑝𝑜𝑟𝑡𝑠 𝑡ℎ𝑒 ℎ𝑜𝑡 𝑑𝑖𝑝 𝑔𝑎𝑙𝑣𝑎𝑛𝑖𝑧𝑖𝑛𝑔 𝑖𝑛𝑑𝑢𝑠𝑡𝑟𝑦 𝑤𝑖𝑡ℎ 𝑙𝑜𝑛𝑔-𝑡𝑒𝑟𝑚 𝑔𝑙𝑜𝑏𝑎𝑙 𝑒𝑥𝑝𝑒𝑟𝑖𝑒𝑛𝑐𝑒 𝑎𝑛𝑑 𝑎 ℎ𝑎𝑛𝑑𝑠-from an approach to the𝑒 𝑐𝑜𝑚𝑝𝑙𝑒𝑡𝑒 𝑝𝑟𝑜𝑐𝑒𝑠𝑠.

Do you know how much zinc leaves your kettle through ash every day? 📊