Hot Dip Galvanising: how it works, when to specify, design tips to avoid delays

If you’re fabricating industrial steelwork, the finish isn’t just a final touch, it’s what helps your work survive outdoors, on site, and in real-world conditions for years.

Hot dip galvanising is one of the most reliable ways to protect steel from corrosion. But here’s the thing: most delays don’t happen because of the zinc bath, they happen because the steelwork hasn’t been designed to vent and drain properly.

At CLA Finishing, we support fabricators, OEMs, and contractors with galvanising and other industrial finishing services from our Stoke-on-Trent facility.

How hot dip galvanising works?

Hot dip galvanising is a process where steel is immersed in molten zinc. The zinc bonds to the steel and forms a protective coating that helps prevent rust and corrosion.

In practical terms, it gives you:

Strong all-round corrosion protection
A tough finish that holds up to handling and installation
long service life outdoors (especially where repainting is awkward or expensive)

If your project needs both corrosion protection and a coloured finish, you may also want to consider a combined approach (often called a duplex system). You can compare finishing routes here: Our Services

When should you specify hot dip galvanising?

You’ll usually specify galvanising when the steelwork will be exposed to:

Weather and moisture (external structures, exposed locations)
Industrial environments
Regular site wear and tear
Difficult-to-maintain installations (where repainting later is costly)

Common steelwork examples include:

Platforms, stairs, ladders, walkways
Handrails and barriers
Frames, brackets, supports
Posts, security products and external fabrications

If the job is internal, cosmetic-only, or needs a very specific appearance, powder coating might be the better option. We also offer powder Coating service.

Design tips to avoid delays

1) Add vent and drain holes early

For hollow sections or enclosed areas, you need holes that allow:

Air to escape
Zinc to enter and exit
The fabrication to drain cleanly after dipping

2) Avoid sealed compartments

Anything that looks “sealed” will cause issues. If you’re capping ends or creating internal voids, the design needs a plan for venting and drainage.

3) Watch overlaps, tight gaps, and crevices

Back-to-back angles, lapped plates, and narrow gaps can prevent good flow and drainage. Where overlaps are unavoidable, detailing should allow access for cleaning and zinc flow.

4) Think about drainage paths (don’t create zinc traps)

Certain shapes naturally hold zinc. Good design helps zinc run off rather than pool, which supports a cleaner finish and quicker turnaround.

5) Be clear about critical zones

If you have:

Threads
Mating faces
Tolerance-critical areas
Electrical earthing points

6) Provide handling / lifting points

Industrial steelwork needs safe handling through processing. Simple, practical lifting points help keep your job moving smoothly.

Ready to galvanise? Request a quote

If you’ve got a job coming up and want dependable corrosion protection, we’ll help you get the specification right and avoid the common design issues that cause delays.

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