At Global Metal Finishing, we understand we are typically the final vendor to handle your parts. Given the meticulous attention to detail of our team, we often identify issues that may have been missed during the machining or fabrication process. Our team diligently identifies defects upfront to minimize delays, however, some problems may only surface after our metal finishing services are completed. 

To help avoid additional lead times and costs associated with reworking components, we offer guidance on common challenges encountered during our finishing processes:

1. Residues left behind after machining and cleaning
2. Lack of alloy identification
3. Absence of fixturing location requests
4. Surface imperfections

1. Residues Left Behind After Machining and Cleaning

One of the most common issues involves residue left behind during the cleaning and machining processes. These various forms of residue can hinder our finishing processes and potentially damage the material irreparably, necessitating re-machining. Here are some examples we encounter regularly in our facilities:

• Cutting fluid residue: When they aren’t properly removed after machining, cutting fluids can prevent uniform dyeing and cause defects. Even water-soluble cutting fluids can pose a problem, as the water evaporates and leaves behind oils that are difficult to remove.
• Cleaner residue: If chemical cleaners are left on the surface, they can penetrate and corrode the material, leaving behind unwanted patterns that cannot be removed.
• Residue from tape or glue: Residue from tape or glue left on parts prevents the chemicals from reaching the surface uniformly, resulting in irregular coatings.

GMF’s Guidance

• Clean parts immediately after machining and carefully dry all residual cleaning solutions.
• Inform our teams if residue from adhesives may be present on the parts. Our team can then remove these adhesives using solvents like acetone before we begin our metal finishing services. 
• Carefully clean and package parts before storage and transportation. Ensuring parts are oil-free is integral to preventing corrosion and markings. 

2. Lack of Alloy Identification 

Different alloys must be processed differently, as anodic coatings form at different rates. Fortunately, our experts can typically determine alloy once processing has started when this information is not provided (or is inaccurate) in a metal finishing service request. However, this can cause a slight delay in production or, worst case scenario in the rare instance our perceptive team doesn’t recognize this discrepancy, it can lead to quality issues that might require rework.

GMF’s Guidance

Provide our team with the most accurate information regarding alloy selections, especially when your order contains multiple alloys. This will ensure the process matches the alloy.

3. Absence of Fixturing Location Requests

It is critical for us to know upfront if a part has specific areas that do not permit rack marks. Appropriate contact and part positioning are necessary for electrical contact and conductivity, so there will be racking marks (typically small bare spots) somewhere on the part. 

GMF’s Guidance

Inform our team where permissible fixturing spots are located so we can process parts correctly the first time.

4. Surface Imperfections

Certain surface imperfections in the base material such as scratches and pits will still be visible after our finishing processes. Flaws may not be visible until after we begin our anodizing service, and at times, our services might even enhance the appearance of these imperfections. 

GMF’s Guidance

If there are any changes in machining, surface prep, tumbling, etc. we ask that the customer makes us aware as this will likely impact the finish they are accustomed to receiving. Any residue that may have begun etching the raw aluminum or causing pitting or oxidation can be irreversible at times. Typically, we will reach out and alert as there are steps we can take together to try to correct these imperfections such as sending back to the customer for repair or we can attempt bead blasting, vapor honing, or a heavier etch to help even out the surface finish. 

The Global Metal Finishing team is eager to support customers’ quality and aesthetic standards. If you have any questions about suggested protocols, don’t hesitate to reach out.

Request a quote to partner with GMF’s all-star team of metal finishing and color experts.