It is not surprising that wet blasting systems have special capabilities when it comes to production of a non-reflective, matte finish on a wide variety of different substrates. This is another case where the unique “scrubbing” action of abrasive media delivered by wet blasting yields very desirable results.
A non-glare or non-specular finish is not only considered by many to be an attractive cosmetic appearance in itself, but there are many types of products where reflectivity may be unacceptable, including optical components, surgical or dental instruments, firearms, and even electrical wire or cable.
Light etching of the surface to produce a matte finish that is low in roughness may be specified as a pre-treatment for anodizing, blackening or other chemical finishes, and certain coating or bonding processes require similar surface conditions. With wet blast finishing, the measured roughness values will depend on the screen size of the abrasive grit, but also on the volume and pressure of compressed air that is injected into the abrasive slurry inside the wet blast gun. Wet blasting systems are capable of delivering a high volume of extremely fine abrasive blasting media, including microabrasive powders.
This lab testing video clearly shows the effect of injecting air into the mixture of media and water, as well as the speed with which the wet blasting system removes surface contaminants and produces a clean, non-reflective finish.
The greater the amount of air in the blast stream and the greater the velocity with which the air-dispersed slurry is delivered, the less the buffering effect of the liquid and the greater the contact between the abrasive and the substrate during the wet blasting process.
To appreciate the finishing power of wet blasting, consider the sheer volume of media that can be delivered to the surface. Take the example of a multiple gun wet blast system with a 50 gallon slurry hopper charged with 50 pounds of aluminum oxide grit. If it is fitted with a pump that feeds 50 gallons of slurry per minute to the blast guns, an impressive 50 pounds of abrasive will be making contact with target surfaces every minute the wet blasting system is in operation!
If you want to evaluate wet blasting for your matte finishing requirements, one of the best places to start is Guyson’s engineering test lab. Contact us to discuss your components and the surface condition you desire, as well as the flow of work at that stage of processing, and we will help you make arrangements for shipment of your test samples and plan to fit the trials into our lab schedule.