Abrasive blasting also known as sandblasting abrasive is the vital media used in the process of cleaning and removing old finishes using specialized machinery. This machine is called sandblaster as it shoots the media down a small nozzle at high speed onto a hard surface removing any rust, paint or grease from an affected area. It is also used to prepare the surface for painting. There are several types of media that are strong, soft, light, and vividly shaped as per your industrial application needs. However, it is highly important to identify only correct media before you come to know where it should be used.
Just as we start the machine, there are some tips that can help us choose the best abrasive medium for our specific blasting usage.
A novice user may not know the resistance of a material he is going to sandblast. In this case a strong media such as steel balls or metal beads projected onto a wooden threshold or a balustrade may put uneven dents to the area and damage the smooth look of the surface. So its always cautious to start with a gentle medium like walnut shells or corn cobs because they won’t cause etching. They are also biodegradable and hence, are the most environmentally-friendly blasting media ever used.
To make for a safer yet strong cleaning results, using glass beads onto your automotive parts or stainless steel surface can be a better option. Glass beads are made of fine soda lime glass that has the least impact on surface and it can be recycled up to 100 times before replacement being a cost effective medium to clean any surface like metal castings and deburring of rough surfaces. So if you like a cheaper option, this is the best.
Harder and tough surfaces like ship decks, heavy industrial surfaces needing scraping and repainting allow for aluminium oxide but moreso, it is finely worked on glass to etch the surface as aluminum oxide is much harder and sharper than glass beads so better know your surface before using it. However, in general cleaning applications too, this media can be applied.
Fiberglass parts are mainly used in the manufacturing of automotive, aerospace and marine products, without etching or stripping and plastic becomes an ideal choice here when you treat your equipments. Applications like fiberglass require gentle treatment and hence require softer media like plastic to remove paint from the surface of fiberglass parts. Using plastic for blasting also results in very low levels of dust.
For faster etching or harder blasting, silicon carbide proves to have an extremely forceful cutting action because it can cut easily through glass, stone or other hard surfaces. It can remove paint from thick and harder metals as well as give a rust-free surface.
If you want to treat your surface somewhat differently somewhat harder in hammerlike action, then using Super-Hard media made from carbon steel is viable. The steel shot is round in shape and is extensively applied for polishing and peening applications. The plane where it is applied offers a more angular shape and sharper texture. However, it can effectively remove rust, paint or scale from harder steel surfaces.
An experienced person knows well where to use which media. Some craftsmen use angular media to scrape and allow for a glazed look while some use a round grit to give sheen to the surface. Sandblasting abrasive media does not necessarily mean blasting by sand as nowadays, more industries are avoiding sand for environmental reasons. Because sand contains silica, it causes serious respiratory illnesses for workers involved in the sandblasting process. It has high moisture so it can also block the air hose or reduce the life of the blasting equipment prematurely. Ergo, sand blasting is a professional work and to start with perfect media, some knowledge is essential.