A SPECIALIST VIEW: RICHARD PADISSON, ANGLO SCOT ABRASIVES

For many years, the surefire method for rust removal and surface preparation in classic car restoration has been grit/media-blasting. The process entails an abrasive medium striking the surface of an object in a stream of compressed air. This action effectively removes rust, paint and contamination from even deeply pitted or contoured surfaces. Once extremely expensive, you can now buy cabinets for under £170, and unbranded compressors to suit from £190.

Although dry-grit-blasting is relatively quick and cheap, it does have some drawbacks. There’s a lot of dust produced that isn’t well-controlled by cheaper units, requiring the use of PPE and the exclusion of the unit from clean areas. As the medium strikes the surface, it causes friction and localised heating, which in turn can damage delicate/thin parts. Finally, microscopic amounts of the medium can become embedded in surfaces, making it unsuitable for critical components. Wet-abrasive/media blasting, sometimes called vapourblasting, reduces these negative effects, the medium being held in suspension in water to create a slurry before being blasted using compressed air. There’s no dust or heat, and the medium doesn’t become embedded in the surface. An added benefit is the cushioning effect of the water on the medium, making it ideal for blasting a variety of delicate parts.