WATER BLASTING MEDIA

Hydro blasting machine, water jetting or water blasting are terms commonly used when describing water as the tool to do surface preparation. The use of water is a technique for cleaning surfaces, which relies solely on the energy and force of water striking a surface to achieve its cleaning effect. In principle abrasive is not used in water blasting systems, hence, the problems caused by dust pollution and by the disposal of spent abrasives are eliminated.

SURFACE CONDITION AFTER WATER BLASTING

Flash rust :

When large areas are water blasted, flash rusting which deminish the original surface standard may occur, before painting can be carried out. The degree of flash rusting depends on many factors, such as humidity level, temperature and the length of time the surface is exposed.

Degrees of flash rust :

• Light flash rust : small quantities of light tan-brown rust will partially discolour the original steel surface. The discolouration may be evenly distributed, or in patches, but it will not be heavy enough to mark an object brushed against the areas.

• Medium flash rust : a layer of light tan-brown rust will cover the original steel surface. This layer may be evenly distributed or in patches, but it will be heavy enough to easily mark objects brushed against the areas.

• Heavy flash rust : a heavy layer of dark tan-brown rust will be completely covering the original surface. This layer will be evenly distributed and will easily mark objects brushed against the areas.