© 2019 by NEPEAN Building and Infrastructure.

Galserv® is a registered trade mark of NEPEAN Building & Infrastructure

FAQs

What is hot dip galvanising?

Hot Dip Galvanising involves dipping steel articles into a molten zinc bath (around 450 C). This forms a zinc coating to protect the base steel.

Why should steel be hot dip galvanised?

Hot dip galvanising forms a zinc layer that is thicker than most other types of galvanising; providing longer corrosion protection.  

Compared to other methods of steel corrosion protection such as paint, galvanising generally offers a lower overall cost, and longer lasting and reliable corrosion protection (depending on application of steel.) See "How long does galvanised steel last?"

Our galvanising service meets the standard according to AS/NZS 4680:2006, which means steel articles will conform to the thickness requirements according to the standard

 

What is involved in the galvanising process?

The process involves cleaning the steel article in several chemical tanks; which includes degreasing to remove any grease, oils and dirt on the steel surface, followed by pickling to remove any rust.

It then enters the zinc kettle, followed by quench and passivation to cool the steel and protect the zinc coating from white rust.

Can any type of steel be galvanised?

We can generally process steel with light/surface rust, and common coating such as light grease and some water based paints. 

When steel is coated in laquer, heavy oil/grease, oil based paints, and large amounts of rust, the steel needs to be sand blasted before it is delivered to our facility.

We can also regalvanise steel that has any galvanised coating at an additional charge.

Steel needs to have minimum dimensions for us to process it. Otherwise that steel needs to be spin galvanised. Feel free to contact us for more info.

Why does steel need holes before galvanising?

Holes are needed in steel articles for hanging purposes, and to allow for venting and draining of chemicals from the cleaning tanks, and the molten zinc in the kettle. Lack of holes can lead to damage to the steel articles and visual defects such as excess zinc lumps in certain areas, and a very rough coating surface.

 

Please consult the below design guide for more information, or feel free to contact us if you have any questions.

Design Guide for venting and draining holes


 

Do you offer pickup and delivery?

Yes, we can pickup and deliver to most areas in Sydney with our rigid and semi trailer trucks.  We charge at an hourly rate for each truck; as per the pickup/delivery requirements. (We do not offer hiab trucks, delivery and pickup sites need to have loading and unloading facilities)

What is the largest steel that can be dipped?

The size of the steel that can be galvanised is restricted by our kettle size, and in some cases the space restrictions of the plant. 

Depending on the overall dimensions, some steel may need to be double dipped. Generally, articles longer than 9.5m, or wider than 2.2m need to be double dipped; which has a surcharge due to processing time.

How long does galvanised steel last?

Galvanised steel will have varying time periods before maintenance is needed; depending on the coating thickness and the corrosivity of the surrounding. This can be over 50 years in less corrosive environments. This is specified under AS 2312.

For more information, see the technical info page

How long does galvanising take?

The galvanising process can have a varying lead time  depending on amount of workload during any given time period. Lead time is usually provided in working days by our customer service team, so feel free to contact us anytime.

 

How much does galvanising cost? 

 

We charge for our service based on the galvanised weight of the steel. Heavier types of steel such as structural beams and channels have a different rate compared to lighter material such as balustrades and brackets. The complexity of galvanising; as it applies to 3-dimensional items, and trailers, will also affect the price for galvanising.

Feel free to contact us to get a quote.

Is there a minimum size order?

If the total weight of the order is below our minimum charge, it will apply. Generally, this applies to orders with less than 65kg for lighter material, and less than 100 kg for heavier structural material.

Why does the finished look of galvanised steel vary?

Galvanising is generally an industrial coating for corrosion protection of steel. The look of the coating can vary from shiny to dull, or rough to smooth coating. 

This depends on the different thickness of the steel and the base steel composition. 

For more information, see the technical info page.