It has come to my attention that customers are bit confused about what goes on in the blast booth.
In their defense, I spend a lot of time and energy talking about our pretreatment and powder coating processes, and significantly less time and energy demystifying blasting.
That changes today. Here are a few quick blasting facts you should know before you schedule your next project.
The hot spot is small.
There’s a reason that blasting parts – particularly large parts – takes time: the removal area (or “hot spot” where the blast medium is most concentrated coming out of the hose) is roughly the size of a golf ball. Contrary to popular belief, a larger nozzle doesn’t necessarily speed anything up. In addition to placing too high a demand on the air compressor, wider blast nozzles dilute the medium. Sure, the hot spot is larger, but it’s less efficient at rust removal, meaning the operator has to move slowly. There are no shortcuts in the blasting business.
Overspray is unavoidable.
Customers sometimes ask me to blast one area while avoiding another. That’s not possible. Steel grit powered at 120 psi creates an abrasive cloud – even a cautious operator using the smallest nozzle cannot keep the blast medium from ricocheting elsewhere. The only way to protect an area from overspray is to mask it, which, depending on the part, can range from time-consuming to impossible. It might be helpful to imagine that blasting is like using a fire hose: expect that everything in the vicinity will be drenched.
Blasting requires stamina.
Setting skill and experience aside for a moment, blasting requires a good deal of physical strength. Think back to the fire hose metaphor. Imagine wrangling that amount of force while standing all day, wearing full-body PPE, and contorting your body into weird positions to reach remote areas. It takes operators a long time to build that kind of stamina. If Stan calls in sick, there aren’t too many people at Kaser who can jump in and fill his shoes.
What questions do you have about blasting? Put them in the comments – I’ll answer them in a future blog.