How to Produce a Visual Blasted Finish
Q. Can you recommend a process that can give a visual blasted finish?
Q. We are vibratory finishing an aluminum part and then blasting it to achieve a uniform pre-anodized finish. Can you recommend a process that can give a visual blasted finish in our vibratory machine to eliminate the blasting process?
A. Vibratory finishing can produce a visual finish very close to the tight patterned satin reflective blasted finish. Certain vibratory medias, compounds and machines are required.
The high-energy centrifugal barrel works best, but vibratory machines also get close.
The two types of medias that work best in obtaining a blasted finish are a random shape 10- to 16-grit ceramic aluminum oxide media, or a smaller ¼ " to 3/8" polyester plastic cone or pyramid-shaped preformed media.
The random media works the best with both vibratory and centrifugal barrel machines and tends to lodge in holes. The smaller, pre-formed polyester media also works in a centrifugal barrel and vibratory processes. The vibratory compounds affect different surface brightness.
Originally published in the January 2017 issue.
The correct peripheral speed is an important consideration in getting the right results from your buffing operation. A buff that is turning too fast or too slow may result in damage to the buff or to the workpiece.
Choice of equipment, media and compounds has a major impact on your finishing applications.
Precision shot peening brings an entirely new concept to the field of microabrasive blasting, and it is complementary to its larger cousin. Using glass bead media, several companies have been shot peening for years with microabrasive blasting technology.