Is all glass bead the same?
And how does this picture relate?
Not all glass bead is destined for use in a blast machine. Dana-Ridge sells Potters Ballotini Impact spheres that are graded by size and designed for use in wet and dry blast units. They are made from soda-lime glass so they don’t contain the harmful ‘free silica’ that can cause long term health issues.
There have been instances where customers have found cheaper alternatives only to discover they are not the bargain they had expected.
There are differing uses for glass bead which can include things like road markings. The beads have good reflectivity, so they can be useful for highlighting safety markings to vehicles on dark roads at night. In these situations, there is little concern for the size of the individual beads or any impurities that may find their way in to the mix. They are added to paint, epoxy etc and tend to be fixed in place once set.
In order to make the spheres as reflective as possible and to help with bonding they sometimes have additives, known as ‘coupling agents’, included for that purpose. These additives can contaminate the media in blasting applications and may cause issues with whatever you are processing.
Due to the variety of uses a product like glass bead has, another important consideration is grading. This is the process of separating beads into different sizes. Different sizes give different finishes in both the wet and dry forms of blasting (wet will achieve much longer media life and a far superior finish). When using for purposes other than blasting it often doesn’t matter so much and even the quality producers will have products available that are a mix of sizes.
In blasting these mixed grades won’t allow you to ‘dial-in’ to what you ultimately want to achieve, ie. a quality surface finish done in a timely manner.
The advantage of larger bead, with its ability to remove coatings quickly and create greater peening effects will be compromised by the small bead. The small bead that usually has the advantage of creating a brighter surface finish and smaller peening effect will be compromised by the large. All in all, the cheaper bead can affect processing time AND quality of finish.
In other words, the worst of all worlds.
In one instance a customer had found cheap glass bead from another supplier, only to discover to his dismay that it dissolved completely in water!
Dana-Ridge supplies a variety of glass bead sizes in 25kg bags. The bead is of high quality, safe clean and well suited for blasting and as with everything at Dana-Ridge, we stand behind the products we sell.