Zinc Spraying London 3

HOT ZINC SPRAYING

Hot Metal Spraying or Thermal Spraying has been used for over 90 years. Molten metal is sprayed on to a pre roughened substrate and on contact the particles spread and bond with each other. This forms a very durable covering which will protect a wide range of products, especially when they are exposed to hostile environments.

Surprisingly the substrate is not affected by heat distortion as the molten particles only transfer a small amount of heat to the surface being sprayed (typically less than 100°C). This is a major benefit, especially compared to hot dipped galvanizing. Thermal Spraying also provides a uniform surface for subsequent coatings to adhere to, thus eliminating the need for time consuming fettling of runs and sharp edges.

Typical applications include

  • Architectural Steelwork
  • Balconies
  • Bridges and Walkways
  • Gates and Fencing
  • Juliet Balconies
  • Pipes and Flanges
  • Railings and Handrails
  • Staircase Stringers
  • Street Furniture
  • Tanks
(Extracted from BS EN ISO 14713)
g) Corrosivity category Im2: Temperature sea water o,e : zinc corrosion rate typically 10μm/year to 20 μm/year: 70g/m2/year to 150 g/m2/year
Typical Life to first maintenance years General Description and suitability Mean Coating Thickness on each surface µm (minimum)
Very Long (≥20) Sealed sprayed aluminium conforming to ISO 2063
Sealed sprayed zinc conforming to ISO 2063
150
250
Long (10 to < 20) As above or:
Hot dip galvanized (see footnote c under table 2f)
Sealed sprayed zinc conforming to ISO 2063
 
150 to 200
150
Medium
(5 to < 10)
As above or:
Hot dip galvanized (thick coating – see note 2 at end of table 2)
115
Short (< 5) As above or:
Hot dip galvanized conforming to
ISO 1461 (steel 3mm)
70 to 85
oHot dip galvanized tube, sheet and fittings normally have additional protection when used in sea water
eBrackish water may be more or less corrosive than sea water and no general estimates or durability can be given
Table 2: Corrosion protection figures