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Emerald Group Publishing Limited
Copyright © 2008, Emerald Group Publishing Limited
Metallisation Arc 170 protecting air bridges in New Zealand
Metallisation Arc 170 protecting air bridges in New Zealand
Metallisation's New Zealand distributor, Metal Spray Suppliers (Nz) Ltd, has supplied equipment and supplies to Edmonds Industrial Coatings Ltd of Wanganui, for its contract to apply a coating system for airport air bridges in New Zealand. Edmonds has won the contract from J&D McLennan Ltd (ael.co.nz), a pioneer and leader in the design, manufacture and maintenance of airport equipment for the whole of the South Pacific Rim. Edmonds Industrial Coatings is a leader in the field of anti- corrosion protection for a variety of industries in New Zealand.
With increased air travel and a diverse range of commercial passenger jets landing at New Zealand airports, robust, attractive air bridges are a necessity. The air bridges also need to be versatile and able to accommodate current and new generation commercial jets, particularly the new Airbus A380.
Typically, Pacific Rim airports are often located on the coast and air bridges are exposed to this harsh marine environment. Coating systems have to provide long-term, advanced corrosion protection and be visually attractive. McLennan specified a finish and quality to the same high standard as automotive bodywork. This meant creating a zinc anti-corrosion coating that was smooth enough to facilitate a functional, yet decorative, paint system and protect the air bridge against the elements.
Edmonds accepted the challenge, confident that its high-process standards and extensive experience would allow them to meet the tight specification and deliver the high quality surface coating required. Edmonds asked Metal Spray Suppliers (NZ) Ltd to provide an Arcspray system that would:
• apply a smooth high quality zinc layer at the fastest rate possible, without having to sand the surface smooth after spraying;
• be flexible and far reaching enough to minimise equipment repositioning and allow the operator good access to the air bridge;
• be ultra reliable in a hostile blast and spray environment; and
• be economical to use and easy to operate and maintain.
The Metallisation Arc 170 push/pull system, with its spray rates and 10m reach, was undoubtedly the only choice for this type of application. The Arc 170 is the fastest hand held anti- corrosion system available providing a high-deposition rate and efficiency, which does not compromise the coating quality or integrity. Edmonds opted for the Arc 170 unit in order to honour its large workload and minimise turn around times. The Arc 170 fast spray rate ensures that blast prepared surfaces are coated as quickly as possible, keeping oxidisation and contamination of the interface to an absolute minimum. This is critical in order to achieve the strongest possible bond to the surface.
Since, Edmonds implemented the Arc 170 equipment, processing time for all anti-corrosion surface treatment is reported to have been cut by half to two days and has eliminated time consuming manual sanding. Edmonds Operations Manager, Craig Thurston, says: “The Arc 170 system is an amazing machine and without doubt the best investment made by Edmonds during my service.”
Air bridges come in many forms to suit the diverse types of passenger aircraft. Larger air bridges are available in two forms, the Apron drive with its distinctive “bulb” is mobile, whereas the LPS is fixed and slides out. The Apron drive is the most versatile and the widely used air bridge, it has a telescoping passageway that can be driven from a parked position beside the terminal to the aircraft itself. The Apron drive will serve many sized aircraft ranging from a Bombardier CRJ all the way up to the new Airbus A380. The A380 version has a special modification to the cab and a longer lifting column. Both types are typically split into three sections, each section is approximately 12 to 16m long.
A complete air bridge can be up to 27m long. Fortunately, with the new Metallisation Arc 170 equipment, and the space available at its extensive facility, Edmonds can complete the anti-corrosion treatment of the air bridges in one process. The complete turnaround time for an Apron drive air bridge is ten days. Resene Paints, working in conjunction with McLennan, developed and specified the post zinc Arcspray paint system that would complement and work in synergy with the zinc layer. Resene proposed a low build duplex paint system that would incorporate all three methods of corrosion protection available – sacrificial, inhibitive and barrier. Using the three-mode protection method the process sequence was:
1 surface preparation to SA3 abrasive grit blast;
2 100μm zinc Arcspray delivered with one pass of the Arc 170 pistol;
3 seal/build coat × two with Resene's zinc phosphate inhibitive epoxy system; and
4 Resene's low sheen urethane top coat × two – developed to suppress reflection from lights at the airport to aid the pilot's vision when taxiing the aircraft to the bridge.
The Resene Paint system is sprayed directly onto the zinc in its “as sprayed” condition. The smoothness of the Arc 170 zinc coating eliminated the need for any dressing or pre-paint preparation, which saved time, labour and expense. The competed air bridge with its attractive yet functional anti-corrosion coating system is then ready for a very long service at any one of New Zealand's airports.
The first air bridge using this innovative system was installed at Wellington airport in October 1997 and since then air bridges have been coated and supplied to Auckland, Melbourne and Sydney, with many more proposed for the Australasian region. Nearly a decade on, the first air bridge coating system is performing with ease in the harsh conditions. J&D McLennan Ltd guarantees the air bridge coating system for 20 years. Edmonds has now provided anti-corrosion protection for more than 40 air bridges.
Metal spraying or thermal spray is commonly used today to protect steel structures from corrosion. In excess of 200 tonnes of zinc wire is sprayed annually in New Zealand to protect steel structures in many different types of environments, from inland to submerged conditions. This represents an area of 200,000m2 with a coating thickness of 75mm or 100,000m2 with a coating thickness of 150mm.
According to metallisation, arcsprayed zinc provides a superior, thicker, greener alternative to galvanising that is not limited by tank size and does not distort the work piece. Coating thickness may be varied from place to place to provide extra protection in critical areas. The process is not limited to zinc and the coating material may be selected specifically for the environment. The coating can be applied on site, without creating any effluent disposal problems. The system requires a reduced stock of zinc, which means working capital is not tied up in a molten zinc bath. Further, savings are made, as fuel is not needed to keep zinc molten when the process is not operational. Metal spraying is also used to restore corrosion protection on damaged areas of welded galvanised steel.
For further information, on surface coatings or the equipment and processes, please contact: Stuart Milton on Metallisation, Tel:+44 (0) 1384 252 464; web site: www.metallisation.com
Caption: A completed air bridge with its attractive yet functional anti- corrosion coating system is ready for a very long service at one of New Zealand's airports.