How a Wet / Vapour Blast Machine Works


To understand what wet or vapour blasting is and where you would use it please see our blog: Wet / Vapour Blasting – What Is It And Why Should You Consider Using It?

Below we describe how a wet or vapour blast machine works:

  • The recirculating high volume flow of water and media are wet blast machine image stripnormally contained within a sealed blast cabinet, built in Stainless Steel or GRP.
  • At the heart of the system is a specially designed pump (A), which can handle and transport the water/ media mix (slurry).
  • The pump transports the water / media mix to the process blast nozzle (B) to be directed onto the target areas of the parts being treated.
  • The process mix (slurry) ratio is controlled (C) and process requirements normally with a range between 15% and 25% of media particulate by volume.
  • With a further addition of a compressed air supply, added at the blast nozzle, additional controlled acceleration can be introduced producing a gentle yet extremely dense blast stream (caution should be noted though that too much air can degrade the performance).
  • A bypass pipe diverts a proportion of the water media mixture, that was on its way to the blast nozzle from the pump, back to the sump (D) to ensure continuous agitation which is vital for suspending media in water and for the consistency of the slurry.
  • Water in the system lubricates, washes and eliminates dust.

Additionally, by adding surfactants, inhibitor and/or degreasing agents to the water / media mix (slurry) oil and grease can be completely removed.

To further enhance the process an indirect heater can be added to the process water/ media mix, to make sure that in a manual application, even on the coldest of days the process is comfortable for the operator.

At the rinse stage, finer particulate is carried over a weir or placed through a cyclone. These finer particulates are required to be reclassified and appropriately recirculated or else they are removed from the process. Cyclones are again employed to perform this task.

Today, wet blast machines and equipment are designed with the latest in house Rősler 3D / CAD capabilities and can be designed and manufactured to suit customers precise requirements and include process control and monitoring. They can also be linked and integrated into an automatic manufacturing line, complete with process quality control and measurement.

Examples of the various parameters that Rősler look to control include:

  • Air pressure and volume
  • Drying
  • Filtration
  • Nozzle angle and range
  • Media ratio / concentration
  • Process speed
  • Rinsing
  • Slurry pressure
  • Water temperature
  • Water pH
  • Water conductivity
  • Water treatment, particulate / centrifugal cutting oil separation and / or removal

When combined, these parameters make a wet / vapour blast process system one of the most controlled available and can be included as a total turn key installation.

Components can be processed individually or in mass form, employing; manual cabinet/s, automatic process cabinets, table type, satellite, barrel type and/or continuous through flow installations. These can be complimented by volume / weight control chargers as well as pick and place robotic handling systems for loading, processing and unloading in a seamless operation.


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Haydn Kitchen New APost written by
Haydn Kitchen
Shot Blasting Technical Manager




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