Powder Coated Aluminium Balustrades Care and Maintenance

1. Outline of the process
2. Introduction
3. General maintenance
4. Restoring weathered, scratched surfaces
5. Anodized Finishes

1. Brief outline of the process:

Aluminium's good resistance to corrosion, and its ability to develop a natural protective oxide surface film, contribute to its outstanding properties as a base for organic coatings.

When the metal is properly cleaned, deoxidized where necessary to remove objectionable residual oxides, then chemically treated to convert its surface to an inert film, it provides an ideal substrate for such finishes.

Thorough cleaning of the aluminium surface and its proper chemical pre-treatment are always of critical importance. The ultimate performance of any applied coating depends more on the preliminary preparation and treatment of the metal than on the subsequent coating application.

In most cases, a five step pre-treatment process is used. Firstly, a thorough clean and etch is used to remove such contaminants as coolants, fingerprints and general shop dirt. After the metal is rinsed, a chromate conversion coating is applied before passing through two more rinsing processes, the last one having the total dissolved solids content adequately controlled so no residues are left on the aluminium.

The metal then passes to the spray booth where banks of electrostatic spray guns reciprocate the full height of the booth. This ensures all critical faces and edges have an even coating of powder.

The electrostatic charge serves two purposes:

By charging the powder, it is attracted to the nearest non-charged surface, this being the object to be coated.

It forces the powder particles to repel each other, similar to that of poles of a magnet, thus aiding atomization.

The excess powder that has not adhered to the substrate is removed from the booth by a sophisticated vacuum system. It is then cleaned and re-used.

The powder coated metal moves out of the booth into the baking oven where the powder fuses and cures to a durable and flexible finish.

Powder coating produces colors which are consistent, have an excellent finish and the system has superb covering characteristics even on complex shapes such as extrusions.

The powders are available in two grades, depending upon the application.

Standard polyester powders are the products most commonly used, with a service life of up to ten years.

High durability polyester powders have higher grade resins and pigments and offer a service life of up to fifteen years.

2. Introduction

All organic surface coatings, liquid or powder will slowly degrade in time with the effect of natural weathering. However a powder coating finish applied to correctly pre-treated metal will offer excellent adhesion and protection, and if properly maintained will last several times longer than a standard type of liquid coating.

One of the reasons for this is that a powder finish is usually applied at three to four times the thickness of liquid coatings and is factory baked and cured under controlled conditions. There are various levels of warrantable coatings which can be offered to extend the warranty of the application such as 5 and 10 year high durability applications.

3. General Maintenance of Powder-coated Aluminium

Cleaning is desirable if the fine finish of powder-coated aluminium is to be preserved. Deterioration of the coating occurs mainly as a result of grime deposition and attack by contaminated moisture, which in a coastal environment contains chlorides and in an industrial or urban environment contains chlorides and sulfur compounds. Deposited grime absorbs contaminated moisture like a sponge and holds it against the powder-coated surface; this permits the attack to proceed thereby damaging the coating, which cannot be restored without removal.

Just as the paint work on your car needs regular maintaining to stay looking in good condition, it is recommended that the powder coating should also be regularly cleaned to remove air born deposits such as salt, atmospheric pollution or general dirt.

The powder coated surface must be regularly maintained in accordance with the powder manufacturer’s data sheets and in areas where there is a high concentration of salt or atmosphere pollutants then a systematic maintenance program meeting AMA 610.1 1979 must be implemented. At the very minimum cleaning should be done at three to six month intervals (depending on location i.e.. Seaside or inland, rural or industrial etc.) and is often part of the regular cleaning program associated with items like the glass of the Balustrade.

The following procedure should be adopted.

  1. Remove dust with a wet sponge rather than risk micro scratching the surface by dry dusting.
  2. Most marks or surface contaminants can be removed by the use of a warm, mild detergent or mineral turpentine.
  3. Wash and remove powder deposits from the powder coating surface using a soft bristle brush or similar.
  4. Always rinse afterwards with fresh water so that the contact time of the cleaning solution is kept to a minimum.


  • Avoid harsh solvents like those incorporated in many household cleaners such as window cleaner or industrial strength solvents. These tend to scratch the surface and in many cases promote premature degradation of the coating that is not necessarily noticeable immediately.
  • Ensure that the contact time of the cleaning agents is kept to a minimum.
  • Avoid abrasive brushes or tools.
  • Test a small discrete surface to confirm the suitability of the cleaning agent used. This will ensure minimal or no damage to the powder coat color or surface.
  • Some sealant and mastic manufacturers recommend solvents such as MEK (Methyl Ethyl Ketone) to clean surfaces marked with their products. Under no circumstances should such solvents be used on exterior grade powders

4. Restoring Weathered or Scratched Surfaces

Where practical a suitable polish can be used to restore tired surfaces or areas that exhibit light scuff marks or scratches. Some restoration products we have found especially good are Brasso or for very fine blemishes, Autosol. Dulux produce LL Gloss Up which has been specifically designed for such a purpose and is applied with relative ease.
Gloss Up does not contain silicon or waxes or other additives that will cause problems further on if recoating the particular surface is undertaken. Appropriate directions are detailed on the container and must be adhered to ensure satisfactory results.

Small (spot) Repairs

Touch up of blemishes or deep scratches can be performed with Dulon Acrylic lacquer, either by artist's brush or fine spray. Most colors have already been matched in two repair systems: Spray cans and Dabsticks.

Dab Sticks: A small brush applicator contained in a 15 ml vial pre color matched to the standard color range. Dab Sticks are available from Dulux .

Spray Packs: A pressure pack also pre color matched to the standard color range Spray Packs available from Shutters R Us Franchising Systems (Aust) Pty Ltd and it's Distributors. Suitable directions for preparation and application are detailed on the individual packages. Handling And Temporary Protection During Transportation And Installation

General: Powder-coated Aluminium Balustrades are delivered to the building site as finished products. Because of the susceptibility to damage of the powder coating during transportation and installation, special care is necessary in handling these products and should not be allowed to rub or slide against each other during transportation. Powder-coated surfaces should be well protected during transportation by interleaving or pressure packing. If contact with unprotected aluminium does occur, that is, on an uncoated surface, the material should be immediately washed off with clean water and the surface dried.

Brick Cleaning: Acids used for brick cleaning can damage the coating and reduce its protective quality. Surfaces should be protected to prevent contact with brick cleaning acids. If contact does occur, the surfaces should immediately be thoroughly washed with copious amounts of clean water.

5. Anodized Finishes

Description of anodizing processes Anodizing produces a high quality finish which resists corrosion, abrasion and exposure to industrial, marine and other severe environments. The choice of either clear or colored anodic films, varying in thickness from 10 to 25 microns, covers a diverse range of applications.

The client, builder or architect can select the natural lustrous clear anodized finish or incorporate any of the wide range of colored finishes. Anodizing is an electrolytic manufacturing process that makes it possible to build a heavy inert oxide film into the metal surface.

Aluminium is placed in an electrolyte, (an acid/water solution) and an electric current passed through the aluminium which becomes the anode (positive terminal). Under the influence of the electric current, oxygen forms on this anode and immediately produces a porous oxide film on the aluminium surface. Extending the duration of this process increases the thickness of the anodic film.

Once the required thickness of anodic film is obtained, the aluminium is removed from the electrolyte and "sealed". Sealing is carried out using hot de-ironised water, steam or room temperature nickel fluoride solution. A reaction occurs between the water (or steam) and the porous oxide film. The resultant film is smooth, hard, homogenous and transparent.

Colors: Clear Anodized is the original process developed that enhances the surface appearance. Clear anodizing is often called natural, satin or silver. Light Bronze, Medium Bronze, Dark Bronze, Matt Black, Bright Silver, Bright Bronze & Gold, Bright Black, and newer décor colors are available.

High Durability: Ideal for exterior applications in suburban and rural areas where cleaning is frequent or where atmospheric conditions are harsh. High Durability has an anodic film thickness of 10 microns and is available in colors of black, silver, light, special (standard), medium and dark bronze.

Extended High Durability: A high quality tough finish developed in strict accordance with AS 1231-1976. Optimum film hardness is established to ensure extra long life and abrasion resistance. As color is not dependent on the anodic film thickness, the most economic film can be specified for the particular application. Extended High Durability is available in colors of black, silver, light, special (standard), medium and dark bronze.

The colors for both High Durability and Extended High Durability are produced by the same electrolytic deposition technique. Stable inorganic metal/oxide particles are "locked-in" at the base of the anodic film prior to "sealing".


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