Abrasive blast cleaning uses abrasive media suspended in a high pressure compressed air stream to impact and remove surface coatings from a substrate (base material) in preparation for restoration painting , coating , or refinishing.
Abrasive blast cleaning is used in many cleaning, preparation, and restoration processes to remove paint, rust and general and surface coatings before refinishing or application of corrosion protection in many industries including:
Abrasive blasting of Waste Skips and Bins prior to prime and paint
Abrasive blasting of Refuse Compactor Bodies
Abrasive blasting of Municipal waste vehicle packer plate and carriage plate to prepare for welding and plating
Blast cleaning of excavator components such as booms, dipper arm, buckets, before refinish.
Blast cleaning of Dumpers and site machinery
Blast cleaning has application processes for restoration of prining machinery to remove printing inks from rollers.
Paint removal from Steel substrate
Paint removal from fibreglass using Soda blasting
Light duty sandblasting to remove paint and rust from motorcycle frames
Soda blasting to remove paint from motorcycle fuel tanks prior to refinishing
Soda blasting to remove corrosion from aluminium engine and gearbox casings
Blast cleaning to remove coatings of rust and paint prior to Non Destructive Testing (NDT) and crack detection.
Shot peening to increase metal surface hardness
Blast cleaning of girders before refinishing
Blast cleaning of Wrought ironwork gates and garden furniture
Surface preparation is a key component affecting finish quality and longevity of the final surface coating. (See BS EN ISO 8501-1:2007 Standard for further information on surface preparation of steels
Sa 1 : Light blast cleaning
Sa 2 : Thorough blast cleaning
Sa 2.5 : Very thorough blast cleaning
Sa 3 : Blast cleaning to visual clean steel ).
A clean contaminant free air supply is required from the air compressor used for blast cleaning. Oil and water is seperated from the air stream using filters and pressure seperator vessel.
Dry abrasive blasting may leave traces of dust which may need removal from the surface to be refinished. Level of dust on the surface can be assessed using adhesive dust tape and magnifying lens. Dust can be removed by vacuuming, air blast, brushing, or wipe down.
The surface finish required is determined by many factors including choice of abrasive media for hardness, blast nozzle type and size, air pressure, hardness of the substrate, speed of blasting .
A wide range of grades of granulated abrasives may be used for blast cleaning including Alumina, Chilled Iron, Corn cob, Crushed Glass,garnet, Olivine (olive shells), Walnut Shells, Sodium Bicarbonate,
Hardness of materials can be measured by various processes eg, Rockwell, Vickers, and Mohs. The Mohs scale relates the ability of one harder material to scratch surface of another softer material. Mohs is often used as a reference for abrasive hardness to select abrasive blast media dependant on the required surface finish of the item to be cleaned.
Abrasives are either expendable or recyclable.
Soda Blasting or Soda Blast Cleaning offers low toxicity and is often referred to as a non-destructive cleaning process when compared to traditional sandblasting.
The Soda blast cleaning process utiliises mild abrasive cleaning action of sodium bicarbonate granules suspended in a high pressure airstream. Sodium bicarbonate is blasted at the surface coating to be removed. As the Soda granules impact the material the granules disintegrate removing surface coatings such as corrosion, paint ,oil, and grease, in the surface preparation process allowing layer by layer strip to bare metal or substrate.
The Soda Blast Cleaning Process has many benefits over traditional Dry Abrasive blast processes.
Green vegetation can suffer leaf damage in contact with Sodium compounds.
The traditional 'sandblasting', shotblasting or Dry abrasive blasting process is very effective at removing surface coatings but has disadvantages of dust creation. Crushed aggregates can potentially produce harmful crystalline silica dust which has been proven to cause Silicosis see also link after long term exposure therefore the materials used must be selected carefully and adequate respiratory protection used, combined with dust control .Dry abrasive blasting produces a more aggressive rougher surface finish. The rougher surface finish can provide a good 'key' for refinishing products. Milder abrasives suh as Walnut Shell, Olive Shell may be used .
Water is added either in the blast pot, or to the blast air and abrasive stream to produce an abrasive slurry. Abrasive slurry blasting offers a fast safer dust free blasting method and controllable method of surface coating removal.
Soda slurry blasting produces a smoother surface finish with reduced risk of embedding blast material into the surface, ideal for Aluminium components.
Advantages of Wet blasting include:
Reduced abrasive consumption therefore lower cost
Increased safety by reducing airborne dusts
Superior surface finish
Water added to the blast cleaning process acts as a lubricant reducing friction therefore allowing the blast process to operate at a cooler temperature. Reduced temperature also reduces the risk of distortion, warping and bending of delicate components such as vehicle body panels which can easily happen if sandblasted.
Wet blasting may cause flash rusting of ferrous components though rust inhibitor additives (eg,Holdtight) may be used to reduce the effects of flash rust, or alternatively a light dry blast clean used as a secondary process.
We currently operate Schmidt Axxiom Accustrip blast cleaning machines. Reports from users have claimed that the highly controllable Accublast system will remove a single layer of paint, print from an egg, print from newspaper.
Blast cleaning operations must be carried out in conjunction with safe working procedures: Risk Assessment , Operator Training, COSHH.
All information on this website is provided in good faith but no reliance on accuracy of information should be made for legal purposes.All trademarks and brands are property of their legal owners and used for reference purposes only.