Aluminum anodizing is complex because many variables affect the finished product, including the alloy’s purity and the metal’s temper. Therefore, machine shops and metal finishers should work together to understand the desired outcome, allowing the finisher to manage the process and achieve the best possible results. 

One of the benefits of anodization is its ability to produce aesthetically appealing colored parts. However, consistently achieving the same color from one lot to another is far more challenging than many customers realize. 

Even under the most controlled circumstances, external factors could result in your parts being anodized in slightly different shades of the same color. (Yes, this variability even applies to clear finishes, which can be more or less transparent depending on the process used!)

We’ll introduce three critical factors that Global Metal Finishing utilizes that will radically affect the final color of anodized aluminum parts—creating better color consistency.

3 Factors That Ensure the Best Final Color of Anodized Aluminum Parts

1. Water quality

While it’s possible to use municipal tap water for anodized aluminum parts, metal finishers don’t recommend it. During anodization, impurities in tap water can cause the final color not to match the intended color. 

Reverse osmosis (RO) water or deionized (DI) water are better than tap water because they contain fewer impurities and lead to a better finished product.

At Global Metal Finishing, we have invested in a state-of-the-art water system to optimize metal finishing services for our customers. The high quality of our water gives customers greater color consistency.

2. Technology and color

Global Metal Finishing maintains tight controls and process tolerances using modern digital color match technology to ensure batch-to-batch consistency. 

Repeatability is vital for critical color outcomes. Using technology helps us measure tank concentration and the color applied to each part during the coloring process.  

3. Working together to meet the desired color 

Global Metal Finishing offers standard and premium colors and a custom color matching service. When color is critical to the outcome of the finished product, our Technical Team works directly with customers to define acceptable color ranges.  

We can find custom color solutions that produce repeatable color consistency that OEMs and prototype customers trust.      

Ensuring Color Consistency 

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Anodizing complexity and variability are even more significant when parts are color critical. 

Suppose you work with multiple finishing vendors across the same project (such as various components in a subassembly). In that case, the variability of inconsistency increases, and the color consistency of your anodized aluminum parts becomes exponentially more challenging to maintain. 

Working with multiple vendors inevitably yields numerous outcomes. Anodizing is a series of chemical reactions linked by small but necessary decisions. Replicating these small decisions from one shop to the next is simply impossible. 

That’s why one of the best strategies for mitigating color inconsistencies is to consolidate metal finishing vendors. Selecting one metal finisher to anodize all batches of a part or all of your subassemblies ensures better color consistency across every run.

We hope you’ll choose Global Metal Finishing as your trusted partner for metal finishing services, so submit a quote request today, and let’s discuss your color-critical requirements! 

Images are courtesy of https://www.nor-vise.com/ and http://www.alliedprecisionusa.com/