Grit Blasting : Definition, Objectives, Materials and Equipment
This article is about Grit Blasting. In this article we will learn the basic of Grit Blasting. Starting from its definition, then its objectives, its materials, its equipment and then finally its procedure.
What is Grit Blasting?
Grit blasting is a process by which abrasive particles are made to impinge on a component to clean or modify its surface properties.
Particles range from walnut shells (relatively soft), through various sands, to silicon carbide, alumina or emery particles, depending on the application.
Methods of propelling the particles also vary and include entrainment in compressed air, liquid (usually water) or vapour (usually steam) streams, and mechanical projection methods (e.g. rotating paddles).
Grit blasting is used to remove sand and scale in the fettling of castings, and for dressing of stampings and billets, etc. It is often used to prepare surfaces before welding (removal of scale, rust or paint), and afterwards to improve the adhesion of coatings (e.g. paint, or galvanising).
The impact of the grit on the metal surface puts the surface layer into compression, and this effect can be beneficial, for example, in reducing stress corrosion cracking in aluminium alloys.
Grit Blasting Equipment
One of the most popular equipment is Clarke CSB20B Heavy Duty Blast Cabinet. We can see the picture of the equipment below :
This Equipment has these following features :
- Uses aluminium oxide for cleaning steel or glass beads for cleaning aluminium.
- High visibility & protective top viewing screen.
- Low voltage (12V) internal light with mains transformer plug.
- Can be used with in conjunction with a vacuum extractor.
- Includes extra filter for cleaner exhaust.
- Air consumption – minimum 10cfm at 8bar.
- Dimensions (LxWxH) 580 x 480 x 490 mm.
Grit Blasting Procedure
The procedure can be learned by watching the following video.
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