Abrasive blasting is an umbrella term for both grit blasting and shot blasting. Many interchange the terminology when in fact there is a distinct difference between the two. In basic terms grit blasting involves using angular particle abrasives and shot blasting using smooth spherical particles.
Here we provide a quick guide to the abrasive blasting media commonly or in some cases uncommonly used.
Garnet is a naturally occurring form of aluminium oxide arranged in the almandine form. It is generally regarded as an expendable single use abrasive with a semi-angular form, available in numerous sizing grades dependant on the finish required and provides excellent cleaning results and is the abrasive of choice here at KUE Group.
Aluminium Oxide is a high grade alumina manufactured from bauxite, silica, coke and iron having exceptional hardness, high recyclability and widely used on non-ferrous items so as to avoid impingement or cross contamination, available in differing sizing grades. KUE Group utilise Brown Aluminium Oxide in many differing applications including the industrial blast cleaning of steam turbine components for NDT / NDE.
Glass Bead is a high grade manufactured soda lime producing near perfectly round particles which when used in blasting techniques impart a polished or lustre finish to the surface, again available in varying sizing grades. KUE Group adopt glass beads where specified by the end user and is used in the industrial blast cleaning of gas turbine components for NDT / NDE.
Chilled Iron is a recast fused iron abrasive with tough, aggressive properties and a high recyclability rate when used on ferrous items, widely available in a large range of sizing grades. It is important to note that if the item being treated is non-ferrous to receive subsequent coating, lining or painting then an alternative suitable abrasive should be sought.
J Blast (Expendable)
Expendable abrasive is commonly referred to as J Blast and was introduced in the 1960’s. A single use only material, the many faceted angular grains provide a large number of ‘cutting’ edges.
Steel Shot is a spherical steel media used in peening ferrous castings and fabrications.
Steel Grit is an angular steel abrasive available in numerous sizing grade ranges.
Stone Grit is a calcium silicate synthetic mineral abrasive used widely in the cleaning of stone.
Crushed Glass is a feedstock for glass bead manufacture but graded and used as an independent angular single use only abrasive.
Walnut Shells are just that, graded and crushed walnut shells and used for its low environmental impact.
Bicarbonate of Soda
Sodium Bicarbonate is often used as a ‘soft clean’ option.
Sponge blasting has been developed for use where low dust is required and reducing the need for dust suppression or dust extraction. The principle being that a chosen abrasive i.e. garnet, chilled iron, aluminium oxide or glass bead is encased in a sponge material reducing levels of dust created.
How To Choose The Right Abrasive Media
All abrasives have qualities that make them better suited to some tasks than others. There is no perfect abrasive, only the most applicable material for your application and budget. Our usual advice is not to worry too much about choosing an abrasive media, as it’s something we can handle on your behalf. We work with a range of materials in our grit blasting and wet blasting processes, and will always select the best solution for your project – to achieve the required surface finish in the most cost-effective way. If you’d like to discuss the subject in greater depth please call 01274 721188.