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Black Dyed Anodize Fading to Red

Has anyone experienced sulfuric acid anodized, black dyed parts fading to red? These parts house electronic communication equipment and have limited exposure to the elements. The black dyes used are high quality from a prominent supplier. Has anyone experienced black dyes fading to red under any circumstances? Any ideas would be appreciated.

Victor Waldman
- Naugatuck, Connecticut, USA
2000

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First of two simultaneous responses--

Most dye suppliers sell more than one black dye, because they have slightly different applications. They also provide average dye fading ratings.

Normally, a dye with a high fade resistance will fade because it was not sealed properly. UV from florescent lights will promote fading nearly as fast as sunlight will for the same light intensity and duration.

James Watts
- Navarre, Florida
2000

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Second of two simultaneous responses--

Easy one to answer, Victor...your parts are poorly sealed..especially if they haven't been exposed to any of the "elements". Have your anodizer check his seal bath, and if necessary, require him to do a dye stain test on a sample part out of the same lot.

Marc Green
anodizer - Boise, Idaho
2000