Parts Cleaning Conference
Published

Glass Bead Blasting as Plating Pretreatment

What are the best practices for using blasting in preparation for plating? Angelo Magrone of Bales Metal Surface Solutions discusses the ins and outs of glass bead blasting.

Angelo Magrone, operations manager, Bales Metal Surface Solutions

Share

Q. Should I blast parts before plating? When should I use blasting vs. chemical cleaning?

A.Let’s take a minute and talk about glass bead blasting. Glass bead blasting is a process used for treating the surface of many different materials for cleaning, finishing, or deburring by applying blast media to a surface, using pressurized air to propel it.

When parts are turned or machined, micro cracks and burrs, and other irregularities of the surface can form. Although these irregularities may not affect the plating, they can cause issues when the parts are in service.

Does blasting damage parts?

Glass bead blasting is not the same as sandblasting. Glass beads are round and smooth, not coarse and jagged like sand. While sand will do the job, it wears the surface down and typically takes away the top layer of material. With the glass beads, it is a peening action to improve the surfaces properties, smooth out micro-cracks, tool marks, and micro burs, and reduce micro pores sizes that you see in powdered or cast metals leaving you a smooth burr-free surface to plate.

Where in the process is it best to blast?

Blasting should not take place until all surface contaminants are removed. Oils and grease impede the effectiveness of the peening action, not to mention soil the media making it less effective for future jobs and causing more frequent change-outs.

Resist the urge to put parts right into your plating tanks after the blasting process. The glass beading process can and will break down the beads, causing dust. This dust sticks to the parts, which will need to be blown off with compressed air and cleaned again in your alkaline cleaner. Remember, we still want the parts to be as clean as possible for plating. Skipping this step can cause missed plating, peeling, flaking, and, if gone undetected, premature part failure in the field.

Advantages and disadvantages of glass bead blasting

Media is generally inexpensive, and many types are reusable. Different media grades are available for various applications specifying a brighter or duller finish. Blasting can remove paint, rust, calcium deposits, scale, and other oxidation. One of the more complex soils (soil meaning anything on the substrate that will interfere with the bond, adhesion or uniformity of the finished deposit) is heat scale — bead blasting is a cost-effective process for removing the heat scale. It quickly gets into hard-to-reach areas like keyways, corners and holes. In addition, glass media is recyclable, making it cost-effective and eco-friendly. You can also use it on most metals, including stainless steel.  

It is important to note there are some important considerations. Glass bead blasting needs to be done in a temperature-controlled environment. Hot and humid locations can clump the media, making it unusable. You must always wear gloves after processing parts as fingerprints can and will oxidize on certain materials, causing the need to re-blast. Also, certain materials will oxidize or rust if not processed right away and left in a humid environment.

About the Author

metal finishing

Magrone
Photo Credit: Bales Metal Surface Solutions

Angelo Magrone

Angelo Magrone is operations manager for Bales Metal Surface Solutions. Visit balesusa.com.

Cleaning Technologies Group
Precision Cleaning Solvents
high-performance systems for efficient parts cleaning
Parts Cleaning Conference
Echoflex modular ultrasonic cleaning machines
Gardner Intelligence
The Finishing Industry’s Education and Networking Resource
Metal Pretreatment Technology
Heatmax Heaters ad with immersion heaters
New Acid-Free Bright Nickel Process
Koch Finishing Systems
Heatmax Heaters ad with immersion heaters

Related Content

Ask The Expert

Troubleshooting Alkaline Zinc

One of the most common problems that can arise when plating with alkaline zinc is an imbalance of brightener in the solution. In this helpful Ask the Expert article, Chad Murphy of Columbia Chemical discusses how different zinc metal concentrations and brightener concentrations can impact efficiency.

Read More
basics

Improving Transfer Efficiencies in Coating Operations

There are many methods for addressing electrostatic grounding in metal painting processes, and Tim Ulshafer from Mueller Electric says the best method for your process is a simple and worthwhile exercise.

Read More
Powder Coating

Coating Systems with the Best Long-Term Performance

The best protection against corrosion and UV exposure, says Axalta’s Mike Withers, is electrocoat and a super durable powder coating.

Read More
Powder Coating

Outgassing and Powder Coating Defects

Having trouble with bubbles forming during curing? Verney Denerville of TIGER Drylac discusses proper outgassing procedures. 

Read More

Read Next

Electroplating

Coping With Staffing Shortages

Tom Mastalerz, business development manager at Columbia Chemical, discusses strategies for optimizing operational efficiencies to help combat staffing shortages.

Read More
Ask The Expert

Using Ion Exchange in Trivalent Chromium Systems

Shane Moore of Pavco discusses the role of ion exchange technology in trivalent chromium systems for maintaining a consistent deposit. 

Read More
Ask The Expert

Longer, Cleaner Plating Bath Life

Angelo Magrone of Bales Metal Surface Solutions suggests adding an agitation and filtration system to keep plating pretreatment tanks cleaner, longer.

Read More
Precision cleaning solvents