Shotblasting is a means of cleaning steel structures by blowing an abrasive media against the steel using compressed air, or mechanical means to propel the grit. Some of the common materials used for blasting are, steel grit, steel shots, expendable, glass beads (bead blasting), olivine and garnet.
A natural mineral abrasive which contains no free silica, Olivine is particularly good for many light blasting applications.
A hard, durable, low-dusting natural mineral abrasive which is capable of achieving high coverage rates. It has a superior cleaning rate - up to twice the performance of conventional expendable abrasives. Garnet is ideally suited for surface preparation in the fabrication industry.
Steel shot is made from high carbon steel which is tempered to give durability and resistance to fracture. It is used to achieve a standard of SA 2½ - SA3 (white metal appearance) and is excellent in the removal of all millscale, rust and paint.
An expendable synthetic mineral abrasive which is widely favoured for open nozzle blasting applications by virtue of its fast rates.
Blasting with glass beads, as opposed to other abrasives, can be used safely for texturing or producing attractive cosmetic finishes, without damaging the base material.
Standards of Blast Cleaning
ISO 8501-1 is the standard that covers blast cleaning, hand flame and acid cleaning. The chart below represents some of the various grades. Our expert Blasters are equipped to achieve any of these finishes.
|Standard||Method||Description of finish|
|Sa 1, SSPC-SP7||Blast Cleaning||Poorly adhering millscale, rust and old paint and foreign matter are removed. Well adhered contaminants remain|
|Sa 2, SSPC-SP6||Blast Cleaning||
Sa 2, SSPC-SP6 Blast Cleaning Most of the millscale rust and paint etc are removed and any remaining is very well adhered
|Sa 2½, SSPC-SP10||Blast Cleaning||Millscale, rust, paint and foreign matter is removed completely. Any remaining traces are visible only as slight stains or discolouration in the form of spots or stripes.|
|Sa 3, SSPC – SP5||Blast Cleaning||All millscale, rust etc is removed and the surface has a uniform white metal appearance with no shading, stripes, spots of discoloration|
|St 2, SSPC SP–2 SSPC SP-3||Hand or Powertool||Poorly adhering rust, millscale etc are removed, leaving surface contamination that is well adhered|
|St 3, SSPC – SP2 SSPC – SP 3||Hand or Powertool||As for St 2, but the surface now exhibits a metallic sheen arising from the metal substrate|
|F1 SSPC-SP42||Flame||Almost all millscale, rust and other surface contamination is removed leaving only a metallic sheen, but some discoloration due to shading left by remaining contaminants|
|SSPC-SP1||Solvent Cleaning||Solvent cleaning is a method for removing all visible oil, grease, soil, drawing and cutting compounds, and other soluble contaminants from steel surfaces|