A guide to abrasive blasting

Abrasive blasting, also known as sand blasting is when a stream of abrasive material is blasted at high pressure against a surface. This turns a rough surface into a smooth surface. The process is used to remove contamination from large surfaces or to prepare outside walls for painting or repair. This article will explain the various types of abrasive blasting which range from high powered industrial to decorative.

DIY

Imagine the effect of sand on pebbles and you will understand the principle behind sand blasting. You can hire a sandblaster from tool hire shops to use yourself. Small sand blasting equipment is ideal for removing loose debris from a wall ready to re-point and paint it. A sandblaster normally usually consists of three different parts; an air compressor, the abrasive and a blaster nozzle. Care should be taken when using blasting sand wet blasting and protective gloves, mask and eye goggles are essential.

Wet blasting

Wet blasting is similar to sand blasting except that water or detergent is added to the sand mix.This creates a lubricating cushion that protects the surface being blasted from excess damage. Surfaces are made extremely clean and particles of the sand from the blaster are less likely to contaminate the blasted surface. Bead blasting Bead blasting uses fine glass beads, which are fired at a high pressure and are less likely to damaging the surface. Bead blasting is primarily used to to remove calcium deposits from swimming pool tiles.

Blasting chambers

An enclosed blasting chamber or room is used when a large item needs to be cleaned on all surfaces. The ideal way for removing rust from wrought iron is, for example to place the item in the Bsat chamber and bead blasting is hurled at high speed across it. This enables the blasting to be done at higher pressure and with minimum risk to the operator.

Decorative

Blasting is also used in decorative etchings and artwork. With glass etchings, for example, the glass is turned semi-opaque by lightly blasting the abrasive across it. This is called 'whiting' or 'snowing' . This is used very effectively to create patterns, images or wording on glass and by speeding or slowing down the speed at which the abrasive is fired, different shades and depths are created. The use of a stencil to protect the glass which remains transparent allows great intricacy of detail.