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How to achieve a consistent gun metal grey colour on anodised aluminium

I am trying to achieve a consistent gun-metal grey colour finish on anodised aluminium. Can anyone advise me of an appropriate dye stuff to achieve this colour. I have had some success using Aluminium Black CRO supplied by Clariant although the results are somewhat inconsistent.

Stephen Price
- Bridgend, UK
2002

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Stephen,

It is my experience that inconsistent color is largely caused by inconsistent anodizing/oxide thickness. Alloy, temp, bath chemistry, racking,and rectifier are all sources of this inconsistence. The more consistent you are with how you anodize the more consistent your oxide and therefor, the ease with which you dye your parts. How tight are your anodizing parameters

Drew Nosti, CEF
Anodize USA

Ladson, South Carolina

2002

Easiest method to achieve uniform matte finishing of aluminum parts is to sandblast the parts using either aluminum oxide for matte or glass bead for semi-gloss. Your anodizing parameters must also remain constant.

Wayne McKee
- Mississauga, Ontario, Canada
2002

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Hello there,

We would recommend for a special dying system in grey colour. This type of dye is available in different colour tones. It has the advantage that is resistant against light and will remain consistent. The company can also send you colour shade samples or charts so that you can make up your mind which colour shade is most suitable for you. The company is "Enthone".

I hope you will be successful!

Best regards,

Thomas Vöhse
- Oberkochen, Germany
2002