Priorior of spray painting, a suitable pretreatment is needed and crucial for high quality surface finishing. For metal piece objects, especially for those heavy pieces by welding production, the popular pretreatment solution is shot blasting or sand blasting. Regardless the technologies being used, the sole purpose of both solutions are mean to clean up the surface such as rust, grease or other contaminations. In order to understand better if we should use shot blasting or sand blasting, following we provide a general comparison for quick start.
What’s Shot Blasting?
Shot blasting is a process of propelling abrasive media material with centrifugal or mechanical force. This abrasive treatment method uses a device of high speed spinning wheel to centrifugally accelerate shot-like material and blast it against a surface. Shotblasting is an aggressive abrasive technique that need a strong application force and a denser media material to clean and prepare a surface.
What’s Sand Blasting?
Sand blasting is a process of propelling that abrasive media with compressed air. This cleaning and preparation procedure takes compressed air as a power source and directs a high-pressure stream of abrasive media toward the given surface.
Sand blasting is a proven pre-finishing technique that’s been around for over a hundred years. Sandb lasting equipment has evolved from uncontained, free-spraying streams of sand creating noxious dust clouds to highly sophisticated contained enclosures with precise abrasive stream control. Sand blasting’s media also changed from sand to more user-friendly materials.
The difference
As definition above, the main difference of shot blasting and sand blasting is the abrasive media and energy source. Shot blasting uses bigger and heavier media particles (metal particles) that are mechanically blasted to product surface. Because of this, the surface physical properties will be roughen due to the high speed shot. And because of this, it’s not suitable for those products that are thin.
Unlike shot blasting, sand blasting is more like sanding. The abrasive media is tiny sand like which can make very smooth surface. And because of it’s powered by air pressure, the surface can be quite clean for next stage treatment.
How to choose?
As learnt above, there’s no better for which. All depends the actual workpiece we’re going to blast. Sand blasting is a smoother and less invasive abrasion process with light pressure and soft media materials like organics or glass, you can treat very sensitive surfaces with little risk of accidental damage.
Sand blasting is the ideal solution for cleaning delicate electronic parts or connectors that have corroded. You have many media options with sandblasting such as aluminum oxide that cuts through surface contamination and leaves the undersurface clean but totally intact. For more abrasion with sandblasting, you can step-up to silicon carbide as a media without worrying about over-doing it.
Shot blasting has its place when you require deep abrasive penetration on denser materials. Where sandblasting might be too gentle and time-consuming for treating gears and shafts, shot blasting will quickly prepare thick and heavy surfaces like metal hulls and truck hubs.
Shot blasting lends itself well to coarse abrasion media like steel shot and steel grit. These are heavy-duty media materials that pound into a surface to loosen caked-on rust or baked-on pollution. Shotblasting is actually used for tougher surfaces than what you’d treat by sandblasting.
