5 Things to Check Before Sending Your Steel for Galvanizing

A great galvanized finish starts long before your steel reaches the kettle. The way a component is designed and prepared has a direct impact on coating quality, turnaround and cost. Here are five things to check before you send your steel to be galvanized.

1. Venting and draining

Hollow sections and enclosed areas need adequate vent and drain holes so molten zinc can flow in and air can escape. Poor venting causes air pockets, uneven coating and — in the worst case — a safety risk. Design vent holes at diagonally opposite corners and size them to AS/NZS 4680 guidance.

2. Steel selection and silicon content

The silicon and phosphorus content of your steel affects coating thickness and appearance. Steels in the “Sandelin” range can produce thick, dull or patchy coatings. If finish appearance matters, talk to us about steel selection early.

3. Avoid weld spatter and surface contaminants

Weld spatter, paint, grease, lacquer markings and anti-spatter sprays don’t pickle off in normal pre-treatment and will leave bare or rough spots. Clean welds and an unpainted surface give the best result.

4. Overlapping surfaces and seams

Tight overlaps trap cleaning fluids and moisture, which can flash to steam in the zinc bath. Either seal overlaps completely or leave a gap and vent them.

5. Distortion and fixturing

Thin, asymmetric or heavily-welded fabrications can distort from thermal stress. Balanced design, symmetrical welding and the right lifting/draining points reduce the risk.

Not sure about your design? That’s what we’re here for. Get in touch and we’ll help you get a better result the first time.