Powder Coated aluminium windows

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Nick Dardalis

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Powder coated aluminium windows are old or new windows of all types and brands but specifically relating to their colour finish. Polyester powder coating remains the most effective way of colouring aluminium profiles but it also provides essential protection to the aluminium surface itself. Here’s everything you need to know about powder coated aluminium windows, how colours are chosen, how to match them with existing aluminium and other tips and advice.

powder coated aluminium windows in a black colour in a modern house

Powder coated aluminium windows explained

In the UK and around the world, polyester powder coating remains the preferred way of painting and protecting aluminium profiles on windows, doors and commercial glazing products.

The powder coating process of aluminium is a sophisticated one, carried out by specialist “powder coaters” in the UK.  These are companies that specialise in painting bar length aluminium that is then used by the window and door manufacturers to make the finished product. These powder coating companies are strictly monitored, quality assured and have all manner of accreditations and certifications.

As well as companies providing powder coated aluminium windows and doors profiles, the company behind the design of the product may also coat and paint its own profiles.

All of the brands of products via systems companies and reputable independent businesses provide powder coated aluminium windows painted to the highest possible standards.

How powder coating differs from wet paint colouring

Powder coating differs from ‘wet paints’ which typically are solvent-based paints that must fully dry and evaporate.

Powder coated aluminium windows are painted using a dry process with polyester powder, hence the term “powder” coated. In simple terms, an electrical charge is applied to the aluminium bar and the powder is sprayed onto it.  The electrical charge bonds the powder to the aluminium and once applied the powder paint is cured in an oven.

Correctly applied by a specialist applicator, powder coating gives even coverage, a high quality finish and one that should last for at least 15 years. Polyester powder itself is manufactured by Powder Manufacturers.  Some are global companies with significant presence, others are smaller companies.

What you may not know is that powder coating has a reduced impact on the environment as powder coating uses no environmentally harmful solvents.

There are approximately 200 polyester powder coat colours available including matt, gloss, satin, textured, metallic and specialist finishes.

The application and painting on today’s powder coated aluminium windows and doors must be painted by an approved Qualicoat applicator in accordance with the relevant British Standards. Guarantees on the paint finish range from 15-25 years as well as specialist guarantees for marine, coastal, extreme, chlorine and other environments.

the powder coated finish on aluminium windows is available in over 200 colours with differing shades of satin, matt or gloss.
The Powder Coated finish on aluminium windows is available in over 200 colours with differing shades of satin, matt or gloss.

What are the colours used in powder coating?

Powder manufacturers use their own product codes that the window industry uses to specify the correct colour.  Whilst product descriptions are used, with hundreds of colours available, the only simple way of ensuring the right colour is chosen is to use codes.

Presently in the UK, the following powders and references are used with examples of colour :

RAL, such as RAL9910 gloss for white.  This is by far the most commonly used method of powder coating aluminium.

Syntha Pulvin, such as G2L0367 Anthracite Grey.  Syntha Pulving like RAL is widely used but typically in more commercial application rather than residential.  It can colour match with RAL colours.

BS 4800, such as BS08B29 Van Dyke Brown used in many brown patio doors installed for decades. BS4800 is largely used to specify colours of paint for construction and building works. Widely used in local authority work.

BS 381C, such as BS381 538 Post Office Red.  Rarely used in architectural aluminium, BS381C colours are used in ironwork and by the military.

NCS, such as S 0585-Y70R.  Rarely used for aluminium, this is an international colour system used by designers, for production, research and education.  It is a colour matching system using printed cards.

Pantone.  The Pantone Colour Matching System is a colour reproduction system. It is rarely used today in architectural aluminium as it is primarily used in Printing. A typical pantone colour can be “Pantone 300 Blue”

How RAL colours work for powder coated aluminium windows

With RAL paint references being the most common for aluminium windows and doors, the paint product codes have been split into colour groups to make identification easier. Each RAL code signifies the colour “group” in the first number: RAL reference starting with 1 – cream/yellow/beige
RAL reference starting with 2 – orange
RAL reference starting with 3 – reds or pinks
RAL reference starting with 4 – purple colours including violet or lilacs
RAL reference starting with 5 – blue
RAL reference starting with 6 – greens
RAL reference starting with 7 – greys
RAL reference starting with 8 – browns
RAL reference starting with 9 – whites and blacks

Can you match colours from different powder manufacturers?

Assuming you have the original colour reference, theoretically, it is possible to match an existing colour with a new one. There are however exceptions such as:

  • Powder manufacturers work to tolerances so it may not be an exact match
  • If aluminium windows have been exposed to the elements and not routinely cleaned, discolouration will  make matching more difficult
  • Some colours may have been discontinued over time.

Therefore if you have old coloured aluminium windows installed, you are trying to replace a coloured window or are adding coloured windows to your home, the original RAL reference is critical.  This even applies to white or black powder coated windows as there are several shades of each colour available. It is also important to remember that some colours are available in either Satin, Matt or Gloss and some colours are available in all three.  Therefore the colour reference must state the shade, such as RAL 9910 Gloss or RAL 7016 Matt.

What about other colours such as Dulux or Farrow and Ball Colours?

If you are wishing to perfectly match a colour you have seen in other types of paints such as Farrow and Ball, powder manufacturers can match your colour.  Please bear in mind that this will incur additional cost as the powder has to be specially made and formulated.  Any additional cost is calculated on a job by job basis and subject to special quotation.

It is worth bearing in mind that most window companies will probably shy away from doing bespoke colour work, choosing instead to stick to the industry standard colour swatches such as RAL. With over 200 colours available you will probably find a close match to wet paint or interior colour but if you are insistent on matching exactly, contact us and we can help you.

powder coated aluminium windows and yellow origin bifolds in a lounge

Summary and Conclusion

Getting the best powder coated aluminium windows means finding a reputable and experienced installer. They in turn work with the best suppliers having access to better products and a wider choice of colours.

Some companies choose to offer only a limited colour range and for many customers, these shades of white, black, grey or woodgrain finishes serve most projects well. If you’re looking for special colours or want to match something specific get in touch for information on aluminium specialists near you.