Metal Spraying

Thermal Spraying Zinc (TSZ, TSA) more commonly known as ‘Metal Spraying’ is an anti-corrosion protection system which is used to extend the service life of another material.

Grade2 IMPACT use modern flame spray technology for application of 3 specific materials – pure zinc, aluminium or zinc/aluminium alloy metal wire.

Zinc & Aluminium are the two most commonly used materials for corrosion protection. The third least common is zinc/aluminium alloy which is generally used in environments where corrosion resistance of zinc is borderline.

The Process Basics

In this thermal spray process, the pure wire is melted using a precisely measured oxy-propane system, atomised using compressed air and sprayed in molten form onto a grit-blasted substrate. Upon contact, the particles flatten onto the surface, freeze and mechanically bond, firstly onto the roughened substrate and then onto each other as the coating thickness is increased.

As the heat energy in the molten particles is small relative to the size of the sprayed component, the process imparts very little heat to the substrate. As the temperature increase of the coated parts is minimal, heat distortion is not normally experienced. This is a major advantage over hot-dipped galvanising.

As a protective system for structural steelwork it is unsurpassed being the only system, recommended by International and European standards EN ISO 14713 as giving greater than 20 years to first maintenance in very aggressive environments such the marine splash zones (category lm2) as well as all other categories.

The benefits of TSZ and TSA – High performance with durability!

In general terms, zinc is used in reasonably low corrosion applications such as water tanks, bridges and general structural steel. Aluminium is used in the harsher corrosion applications such as salt water and splash-zone areas. Aluminium is also used in high temperature areas such as flare booms or pipework on off-shore oil rigs, this is because aluminium effectively dissolves into the substrate when exposed to high temperatures – traditionally known as aluminising.

  • Fast turnaround as coatings require very little drying or curing times.
  • TSZ suitable for in service substrate protection > 200 ºC
  • TSA suitable for in service substrate protection > 400 ºC
  • Thermal sprayed zinc coatings can be applied to a far greater coating thickness accuracy ranging from 50 microns to 250 microns. We have total control over the zinc thickness applied.
  • Low heat input during Hot Zinc spraying eliminates the risk of the thermal distortion of fabrications (especially thin walled frames and curtain walling).
  • No drilling of sealed hollow section required with Hot Zinc Spraying.
  • No dross produced with Zinc Spray, hence eliminating fettling of components (eg. Handrails) which can invalidate galvanizer’s anti-corrosive warranty.
  • Eliminates handling Health and Safety issues with razor edges and drip spikes etc. (especially on handrails or balustrades).
  • No weld lift with TSZ/TSA. Welds remain completely flat and consistent.
  • Thermal Sprayed Coatings are the only coating systems recognised by International and European Standards EN ISO 14713 as giving greater than 20 years to first maintenance in very aggressive environments.
  • TSZ & TSA Coatings provide far superior bond strength for paint systems as it provides an excellent profile unlike ‘shiny’ galvanized coatings.
  • Metal Sprayed components can be powder coated or wet sprayed to produce a beautiful blend of corrosion resistance and superb appearance.
Quality Assurance and Approvals
  • Grade 2 IMPACT are accredited with ISO 9001: 2015 & ISO 14001: 2015 and strive to produce the expected high standards required to produce quality work within the industry.
  • Grade 2 IMPACT also hold SSIP Accreditation with CHAS & Safe Contractor and hold Silver Membership with Construction Line.
  • Our TSZ & TSA operators are certified by Metallisation’s School of Thermal Spraying Technology.


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