"Engineered Surfaces for Exceptional Performance"
"Engineered Surfaces for Exceptional Performance"

Article Index

Metal Spray is the ideal surface to receive any top-coating from painting to powder-coating with any available colour!  Metal Sprayed coatings are used to provide superior and reliable resistance against corrosion.


Children's Playground Equipment

Reason for use: Durable corrosion protection layer under powder coated top coat.

A Metallisation Arc spray system has been used to protect playground equipment from corrosion and to create an excellent base for the powder-coated finish. SMP (Playgrounds) Ltd has selected Metallisation’s Arc spray system and zinc coating process, to protect its wide range of outdoor playground equipment. SMP has been designing, manufacturing and building playgrounds throughout the world for 40 years.

The safety of the finished surface is critical to SMP, as is the long-term protection against corrosion provided by the zinc metal spraying process. Since 1999, updated safety standards for play equipment design have been introduced in Europe. It is a priority for SMP to be compliant with these new standards.

The European Standard for children’s playground equipment EN1176 states that the equipment must be protected from corrosion and no toxic paints are to be used. SMP uses a multi-stage process to offer optimum protection and a safe, compliant coating in their playground equipment.

The zinc coating itself is all that is required to protect the steelwork from corrosion but to ensure added protection, a zinc rich primer is also applied to a thickness of 60-80 microns. As there is no curing time for the metal sprayed coating, the play equipment can move immediately on to colour powder coating so the process is very efficient. The complete process is also within the control of SMP so they are assured that their high standards of quality and safety are met on all of their equipment.

The appearance of the zinc coating and primer does not lend itself to children’s playgrounds so the play equipment is finished with a 60-80 micron thick, high gloss powder coating.

A common issue when powder coating over metal sprayed coatings is the appearance of bubbles in the surface. This is due to the porosity that is always present in arc and flame sprayed coatings expanding during the powder coat curing time in the oven and the bubbles rising to the surface.

There are 3 main solutions to this issue. Firstly, you can use special powders with anti-gassing additives. These stop the surface of the powder coat hardening too quickly and hence allow the bubbles to escape before the powder coat cures. The second option is to de-gas the coating before powder coating, which basically involves pre-heating the items to be coated to expand the gases before powder coating. This is not a popular choice, as it requires additional ovens and / or time. The third option practised by SMP is to ensure that the coating is as smooth as possible with minimal porosity. SMP has honed the Metallisation equipment and spraying process so well that they are able to spray very smooth coatings with 2mm wire and do not have problems with bubbles. A number of factors allow SMP to achieve the smooth coatings.

The Metallisation equipment is designed solely for metal spraying and the energiser produces a very even power supply. When combined with an accurately controlled Arc Spray pistol, the result is a very stable arc and hence a high quality coating. The quality equipment, combined with using the optimum parameters, excellent housekeeping and maintenance procedures, including a twice yearly Metserve preventative maintenance contract, ensure that the systems are always in optimum condition. The complete coating process enables SMP to offer a 5-year corrosion guarantee on its range of coated equipment but it would actually expect a time span of around 15 years before corrosion is an issue.

In the Metallisation Arc spray process, the raw material - in the form of a pair of metallic wires, is melted by an electric arc. This molten material is atomised by a cone of compressed air and propelled towards the work piece. The molten spray solidifies on the component surface to form a dense, strongly adherent coating suitable for corrosion protection and wear resistance.

In March 2006, SMP Playgrounds purchased its second Arc Spray system. Both systems will be used instead of flame spray systems and SMP report noticeable cost savings over flame spray now that they are using the two Arc Spray systems. This is because the arc spray systems do not use gas and oxygen and only need electricity and compressed air to run. Fewer consumable spares are also needed with arc spray systems. The zinc spray material is supplied as 2mm wire in 2 x 250kg drums, which allows them to spray for long periods of time without the need to change the wire supply.

SMP designs and manufactures a diverse range of playground equipment suitable for public parks, leisure areas, holiday centres, hotels, and schools. The equipment ranges include everything from swings, roundabouts and slides, through to specially designed structures for very young children and stylish futuristic equipment for older kids. The equipment ranges are designed to encourage interactive play, stimulate imagination and physical activity and allow accessibility for children of all abilities.

Robert Wilson, Production Director at SMP, said:

“We understand the responsibilities and challenges facing playground providers and operators today. Our aim is to help them create a successful playground area that is fun, challenging, safe, durable and as vandal resistant as possible. The finished surface of our equipment is critical and the corrosion protection offered by the Metallisation process helps us to achieve the required results. The Metallisation equipment is very reliable and is also covered by a Metserve preventative maintenance contract. This ensures that our high quality coatings and production is maintained with the minimum of unplanned downtime, which is critical to customer service.”


Balconies/Railings

The metal spraying process is used to provide protective coatings on balconies, fences, railings, and general architectural steel fabrications to prevent corrosion.

Thermal sprayed zinc (TSZ) coatings are often applied using either the flame spray or twin wire arc spray process. Depending on the environmental conditions and application requirements, aluminium (TSA) or zinc/aluminium (TSZA) coatings can also be applied using the same processes and tend to be used for industrial or coastal conditions. The metal sprayed coating provides an excellent base for a paint or powder coated top coat.

Often, these items would be galvanised but thermal spray is an excellent alternative to the hot-dip-galvanise process. There is little to no heat distortion with thermal spray making it ideal for thin, lightweight structures which would normally distort in a hot-dip galvanising bath. The size of the objects to be sprayed is limitless allowing large balconies and fabrications to be coated without restriction of the size of the galvanising bath. The Metal Sprayed coatings offer sacrificial (zinc), barrier (aluminium) or a combination of protection in the case of zinc/aluminium alloy. Depending on the coating thickness and environment, independent standards (EN ISO 2063) suggest that the coating life to first maintenance can exceed 20 years of protection.

The applications are wide ranging from domestic railings to playground equipment through to industrial equipment railing or sports facility barriers.


Polish LPG Bottles Protected by Metallisation Equipment

Automated zinc spraying of gas cylinders (LPG cylinders) is made possible with automatic arc spray systems.

This can be onto brand new cylinders or on reclaimed/repaired cylinders. The zinc coating is applied to give longer corrosion protection to cylinders compared to paints alone. The paint or powder coating layers are often damaged during manual handling and the zinc coating beneath provides a sacrificial coating.

Reason for use: Long term corrosion protection of LPG Bottles.

Vitkovice Milmet S.A. is the only manufacturer of LPG bottles in Poland and has recently purchased three Metallisation Arc spray automatic production metal spraying systems. The steel cylinders, which are mainly used for Propane and Butane gas, are produced from scratch at the company’s site in Sosnowiec and, as with all steel items, are prone to long term damage by corrosion.

Vitkovice Milmet has purchased the metal spraying equipment in response to demands from the LPG cylinder industry for more superior and reliable resistance to corrosion. To provide the level of corrosion protection required, each bottle needs to be metal sprayed prior to powder coating or wet painting. Metal sprayed bottles will be fit for useable service for between 10 and 15 years before routine inspection is required. Metal spraying is a technology that protects or extends the life of a wide variety of products in the most hostile environments.

Normally, LPG bottles are simply coated with either wet paint or a powder coat, which are both liable to damage through normal wear and tear, leaving the metal exposed and leading to corrosion. As an effective protection from corrosion, Vitkovice Milmet has been considering metal spraying for some time and began investigation into this nearly ten years ago, before the demands of the industry were evident.

In 2007, the Vitkovice Milmet management team visited Metallisation in the UK to see first hand how metal spraying can protect LPG bottles from corrosion. The team also visited a number of bottle spraying plants across Europe and Scandinavia to witness the effectiveness of metal spraying gas cylinders. While in the UK, the Vitkovice Milmet team also visited leading automation company, EMS Surface Technology Ltd (EMS), based in Reading, to evaluate the equipment that would enable the metal spraying process to be fully automated.

Following extensive evaluation and discussion Vitkovice Milmet chose Metallisation to provide all of the metal spraying equipment, and EMS as the main contractor and supplier of the automation. Vitkovice Milmet’s decision to opt for Metallisation was based on the professional approach of the team in the UK, recent references for the same application and the local support service provided by established Metallisation distributor, Sciteex.

Vitkovice Milmet’s initial brief to Metallisation and EMS was to metal spray the cylinders while in a vertical position. This, unfortunately, can create a range of technical problems and can increase the cost of the automation as well as producing an uneven coating. Following lengthy discussions, Metallisation and EMS were able to demonstrate the benefits of spraying the bottles in a horizontal position, which Vitkovice Milmet agreed to and adopted the principle.

Vitkovice Milmet’s target production is to spray 2,100 of the 11.3kg bottles per day across three shifts. The adaptable automation in conjunction with the Metallisation automatic Arc Spray systems can spray a range of bottle sizes between 3kg to 33kg in weight, between 320mm and 1330mm in length and a diameter range of between 215mm and 375mm.

Vitkovice Milmet make the bottles by first pressing the parts which are then welded together with the fixtures, before pressure testing them prior to applying a surface coating. The surface of the bottles needs to be prepared to ensure an adequate profile is created for metal spray adhesion. This is done by grit blasting the bottles in an automatic blasting machine, which produces a blast cleanliness of SA 2.5. Once the surface has been prepared, the metal spraying can begin.

The bottles are automatically fed into the metal spray machine, which aligns the pistols and rotates each bottle. One metal spray pistol moves across the base and sprays the bottom of the bottle, a second, fixed pistol, sprays the bottle neck and shroud and a third pistol traverses along the length of the bottle to coat the sides. The machine is also supplied with dust extraction and dry filtration equipment, to ensure there is no contamination of the coating and to provide a safe working environment.

Each bottle is coated with an average of 60 microns of zinc. The base of the bottles is coated with a slightly thicker coating to provide greater protection in an area normally subjected to greater wear and tear. Once all the bottles have been metal sprayed, Vitkovice Milmet then powder coat the bottles to meet its customer colour requirements. Bottles are then fitted with valves, pressure tested, certified and stamped and finally branded with the customers branding using screen-printing.

Vitkovice Milmet chose the Metallisation Automatic Arc Spray System as it provides a consistently high quality zinc coating and can spray zinc at a rate of up to 46kg per hour. The Arc 528E pistols (used to spray the base of the bottles) are connected to two S250, 250 amp energisers. The pistol spraying the sides of the bottles is connected to an S450, 450-amp energiser, as this needs to spray at a higher spray rate than for the base and neck. The zinc is supplied in 250kg fibre drum production packs.


Architectural Steelwork Corrosion Protection

Professional Coatings Adds Zinc Metal Spraying to Its Coatings Range

Reason for use: Corrosion protection of architectural steelwork.

Professional Coatings Limited purchased a Metallisation Arc Spray system to add metal spraying as an option to its vast range of paint and powder coating finishes. Professional Coatings, based in Newbury, Berkshire, offers superior anti-corrosion protective pre-treatment with architectural grade polyester and nylon-plastic coating systems to the manufacturing industry throughout the UK.

Professional Coatings Limited

In a recent project, Professional Coatings was asked to coat a range of balcony parts including the support columns, balcony decks and curved railings. In total 34 parts were sprayed. The columns and railings were metal sprayed and then powder coated and the bases were hot dip galvanised and powder coated. The company opted for this system for the bases, as it was impossible to get line of sight to all areas of the bases.

Professional Coatings opted for its preferred method of metal spraying the railings and supports with zinc, rather than hot dip galvanise before powder coating, as the Metallisation process enables a superior final powder coat finish in comparison to a hot dip galvanised base coat.

Metal spraying also means that no fettling is required, it gives Professional Coatings control over the quality of the finish and can be scheduled to suit its own timescales, rather than relying on a third party galvaniser. One of the key advantages of metal spraying over hot dip galvanising is that it is a cold process, which means there is no distortion of the railings or any risk of ‘spikes’ on the handrails, a basic critical requirement in the painting and coating of handrails and balconies from a safety point of view. This system dramatically reduces the ‘Carbon Footprint’.

The specification was to blast the balcony parts with steel grit to SA 2.5. Following the grit blasting, Professional Coatings applied 50 – 70 microns of metal sprayed zinc, which was checked for accuracy using a Positest DFT measuring device. The next stage was to apply a coat of architectural grade polyester powder and green bake it so it was not fully cured, before applying a top coat of the same powder and finish bake both coatings. This achieved a perfect finish without surface blemishes – a standard demanded and expected by Professional Coatings’ long-standing and prestigious clients.

The finished thickness of coating is in the region of 250-300 microns. As per the European standard EN ISO 14713, this coating system has an expected life to first maintenance of 20 years plus in many environments. Professional Coatings guarantees that the powder coating will not flake off. Its confidence in this guarantee has been increased by the higher quality of bond achieved with powder coating over metal spray as opposed to conventional hot dip galvanising.

High Quality Powder Coating

Even as experienced coaters, Professional Coatings had no knowledge or experience of the metal spray process prior to this project. Having discovered the improved, high quality finish after powder coating, combined with the control provided over the standards and coating finish, the decision to opt for metal spraying was made easy.

Professional Coatings’ whole experience during the set up and initial stages of metal spraying was very positive. Professional Coatings’ operators expected the equipment to be more problematic than it actually was. However, subsequent feedback has been that the Arc Spray system is particularly easy to use and offers the flexibility to spray different shaped structures. It can be a little messy with the dust produced but this has been easily overcome with some minor planning changes. The dust is also easy to clean up as over spray does not stick to the surrounding area. The operators have been surprised by the amount of work achievable and have found that it’s not as wasteful of coating material as they previously thought it would be.

Feedback from Professional Coatings’ clients has been very positive and has resulted in more regular business, with customers now requesting zinc metal spray as a base coat instead of hot dip galvanising. Since March they have done around 15 – 20 metal spray jobs ranging from balconies to gates and gate posts, fences and various architectural fabrications.

Testing Powder Coatings

For a number of years Professional Coatings has tested its powder coated systems with test vehicles all over the world in extreme conditions from the Sahara desert to the arctic. Professional Coatings takes great pride in testing its system to a higher degree than the manufacturers and feels that its coating systems and products could be of tremendous value to other areas of industry.


Metal Spraying is Huge Success with Electro Metal Depositors

Metallisation customer, Electro Metal Depositors, are huge fans of metal spraying and says its clients are thrilled with the results.

Electro Metal Depositors, based in Oldham, Lancashire, UK provides anti-corrosion and surface protection for all manner of equipment and structures including turnstiles, playground equipment, security barriers, entrance gates, roadblocks and decorative balustrades.  The company prides itself on providing surface coatings that offer corrosion protection, durability and longevity. 

Metallisation supplies Electro Metal Depositors with Arc Spray equipment, wires and supporting sundries for use in all of its metal spraying projects. The Metallisation Arc140 system offers a lightweight, medium capacity solution for both anti-corrosion and engineering coating applications. At the heart of the system is the patented ‘Synchrodrive’, which reliably and positively drives the wire at the dispenser and the pistol, allowing the pistol to be up to 20m from the wire. The flexible drive system means that there is no motor in the pistol, resulting in a lightweight, manoeuvrable pistol, increasing the flexibility of the system and reducing operator fatigue. 

Although Electro Metal Depositors provides metal spray solutions to many industries and clients around the UK, the company has recently completed two exciting major projects with its client, Broughton Controls Ltd. The first was to protect the entrance turnstiles of an Irish rugby stadium. With a capacity of 50,000, the turnstiles at the rugby ground will be well used, which means they need to be hard-wearing and protected from corrosion. To achieve this, the turnstiles were metal sprayed with zinc and finished with a powder coating. The metal spraying provides an excellent key for the powder coat to adhere to, assisting in the long term durability of the outer coating. Should the powder coat be damaged, by jeans rivets or belt buckles for example, the zinc metal spray comes into its own and protects the base steelwork from rusting. Rusting of turnstiles and handrails can cause sharp areas, obviously undesirable given the amount of people passing as well, as the aesthetic issues.

The combination of metal sprayed zinc and powder coat has provided a hard wearing, anti corrosion coating guaranteed for at least ten years.

The second project was to protect the entrance turnstiles at a defence site in the UK. Again strong, robust, hard-wearing surface protection was required, which has been delivered by metal spraying the turnstiles with zinc. This time Electro Metal Depositors has provided a 20 year guarantee to its client. 

In the metal spraying process surface preparation is very important to the success of the final coating. All of the surfaces are therefore prepared by grit blasting with steel grit to SA 2.5, which ensures the surface area is ready to accept the metal sprayed particles. Electro Metal Depositors aims for around 70 - 100 microns of zinc spray and between 70 – 100 microns of powder coat, which gives a total of 140 – 200 microns of protective coating on all projects. 

One of the major advantages of metal spraying, as opposed to a process such as galvanising, is that there is no heat distortion of the structures being coated. This is vitally important in the protection of decorative balustrades the company manages on a regular basis.  These balustrades can be intricate and delicate mouldings in metal that will be easily distorted by the heat generated in the galvanising process. 

A second key advantage of metal spraying over galvanising is the ability to protect large structures. Galvanising is limited to the size of the galvanising tanks and therefore cannot accommodate large structures. Whereas metal spraying has no limitation on the size of the structure it can protect.  This was a key factor in the company’s decision to metal spray large roadblocks, which are huge steel structures used in war zones.  The roadblocks needed to be protected from corrosion, but also robust enough to withstand an explosion. 

Richard Mc Partland, Chief Executive, Electro Metal Depositors, says: “Metal spraying is fantastic. Its strength, durability and long term protection is ideal for the work we are asked to do by our clients. The security companies love metal sprayed surfaces because it is just so strong. It not only provides corrosion protection but it creates a hard wearing, strong surface that lasts for years.  We recently used it to protect the security barriers at the site of one of the large banking groups and it has been a huge success. Metallisation is a great company to work with. They are always on hand to offer support and to discuss new developments with us. I am a big fan of metal spraying.”

For more information on Metal Spray equipment or consumables, call us on 07 3823 1004, or email us using our contact form.