Copol^®

Pre-treatment of Aluminium

Pretreatment Standards

The pre-treatment process should be capable of meeting the performance outputs as described in AS3715.

Compliance to appropriate process parameters is essential in ensuring compliance to etch, conversion coating weights (time/concentration) and conductivity of the final rinse.

Etch

The etch process is a very important stage of pre-treatment and close consultation with your pre-treatment supplier is strongly recommended to ensure optimum adhesion & corrosion resistance is obtained. As an approximate guide:

• An etch rate of >1gm/m2, is recommended for Copol projects but etch rate advice from pre-treatment suppliers should be taken into consideration.

Conversion Coatings

This is the next pre-treatment process for aluminium to ensure that it is suitably prepared for coating. It is recommended that Chrome conversion weights be a minimum of 431mg/m2, but advice from pre-treatment suppliers should be taken into consideration.

• Non Chrome conversion coatings should be applied and maintained in accordance with the manufacturer’s instructions.

Final Rinse

Final rinse is to ensure optimum surface preparation prior to coating.

• Final rinse water run-off from the extrusion is recommended to have a conductivity of less than 80 micro Siemens/cm.
• The entire area of the aluminium shall be properly pre-treated, appropriate spacing devices should be used.

Handling

Care should be taken with handling to ensure health and safety measures are met and that the substrate is not contaminated.

• Pre-treated aluminium must be handled very carefully with clean lint-free gloves and powder coated within the time specified by the pre-treatment supplier – this is generally within 16 to 48 hours.

Dry Off Oven (if applicable)

If your site uses a dry off oven to assist in the pre-treatment process please ensure:

• Post rinse dry off temperature – consult your pre-treatment supplier but generally:
  • < 75° C for chrome pre-treatment,
  • < 120° C for chrome-free pre-treatment.

Pre-treatment of Steel

PREPARATION FOR STEEL SUBSTRATES:

1. Wash and degrease all surfaces to be coated in accordance with AS1627.1 with a free-rinsing, neutral/alkaline detergent, in strict accordance with the manufacturer’s written instructions and all safety warnings.
2. Wash with fresh potable water and ensure that all soluble salts are removed. Testing if required can be done in accordance with AS 3894.6 for the determination of residual contaminants.
3. Grind all sharp edges with a power tool to a minimum radius of 2mm.
4. Hand or power tool clean welds to AS1627.2 to remove roughness. Remove filings, preferably by vacuum.
5. Abrasive blast clean all steel surfaces to be powder coated in accordance with AS 1627.4 to the visual cleanliness standard of SA 2.5.
   Use a medium that will generate a surface profile of 35 to 65 microns. In situations where it is not possible to prepare your item on all surfaces as described above, for long term protection against corrosion it is strongly recommended whenever possible, that an alternative substrate such as aluminium be considered.
6. The steel must be coated within 4 hours of blasting and stored in an area which is clean and dry.

Application

Application Method

Electrostatic Spray

Cure Schedule

Packaging Pre Installation

Attention to packing is essential for powder coaters and fabricators to ensure that all powder coated sections are received in good condition.

When packing powder coated assets, it is recommended that;

• Sections must be adequately cooled prior to packing the metal temperature must not exceed 40°C on packing.
• Appropriate protective wrapping is recommended prior to packing to avoid damage during transport. It is recommended these are tested prior to use to confirm they are suitable.
• If protective tapes are used, ensure that the tape will remain removable following transport, fabrication and installation and not irreversibly mark or damage the coating. Tapes should be used in accordance with the manufacturer’s instructions and only remain in contact for the minimum amount of time. It is recommended these are tested prior to use to confirm they are suitable.
• Packed metal should be kept away from direct sunlight and moisture to avoid coating defects.

Care & Maintenance post installation

It is recommended in environments with low salt, low pollutants and in urban areas that cleaning should take place at a minimum of every twelve months. In areas where salts, pollutants and high corrosivity levels are prevalent, e.g. beachfront houses or industrial areas, it is recommended a cleaning program should be carried out more frequently at a minimum of every six months.

Sheltered areas can have a higher risk of coating degradation as wind-blown salt and other debris or pollutants may adhere to the surface and not be removed when it rains. These areas may require more frequent cleaning.

Use the following table to identify the recommended minimum cleaning and maintenance schedule for your project. The table references AS2312.1, SNZ TS 3404 and ISO 9223 to identify the environment, conditions and atmospheric corrosivity categories.

Three steps to cleaning powder coated surfaces

Care and maintenance schedules are essential to ensure that the life of your asset is maximised whether the project be a residential, commercial or non-habitable project. Simply follow 3 important steps:

1. Carefully remove any loose surface deposits with a wet sponge by gently rubbing.
2. Clean by gently rubbing the surface with a soft brush (non-abrasive) and a dilute solution of a mild detergent, e.g. pH-neutral liquid hand or dishwashing detergent in warm water to remove dust, salt and other deposits. For stubborn stains use only recommended solvents on the affected area, e.g. Isopropyl alcohol (IPA) or methylated spirits and rinse off with clean water. Do not use other aggressive solvents.
3. Rinse the surfaces with clean fresh water after cleaning to remove all residues.

Warning

Aggressive solvents such as turpentine, white spirits, thinners, citrus based cleaners and other aggressive solvents are harmful to the extended life of the powder coated surface. These solvents should not be used for cleaning purposes
If paint splashes, sealants/mastics or stubborn stains need to be removed use only Isopropyl alcohol (IPA) or methylated spirits and rinse off with clean fresh water.

In some cases, strong solvents recommended for thinning various types of paints and also for cleaning up mastics/sealants are harmful to the extended life of the powder coated surface. These solvents should not be used for cleaning purposes. If paint splashes or sealants/mastics need to be removed then the following solvents can be used safely: Methylated Spirits, Ethyl Alcohol, Isopropanol.

For more information about care and maintenance click here.

Project Suitability – Aluminium

The following table can be used to help identify if Copol is suitable for your project.

Project Suitability – Steel

The following table can be used to help identify if Copol is suitable for your project.

Conditions:

Use the following table which references AS2312.1, SNZ TS 3404 and ISO 9223 to identify the environment, conditions and atmospheric corrosivity categories.

Advice Line

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