Technical Brief Nov 2016 - Primas Dry Ice Blasting - Is dry ice really a non-abrasive blasting media?
A study published by Clemson University (Molen, Joosten, Beentjes and Megens, 2011, p. 96) found dry ice pellets to be 1.5-2.0 on the Mohs hardness scale.
The Mohs scale is used to characterise mineral hardness through the ability of a harder material to scratch softer material and the softer material not being able to scratch the harder material.
Using Mohs methodology it can be argued that dry ice particles are non-abrasive to all substrates that are harder than dry ice or above 2.0 on the Mohs scale.
The following table places dry ice on the Mohs scale and identifies it as being the softest or least abrasive blasting media.
Notwithstanding the relative softness or non-abrasiveness of dry ice compared to other blasting media it is important to understand that dry ice blasted at a surface using a high pressure stream can cause damage to surfaces and equipment if strict professional practices are not observed.
Primas Dry Ice Blasting continues to refine and augment its technical understanding of specific contaminates, substrates and environmental conditions and how best to safely and effectively dry ice clean when encountering ever changing combinations of these factors.
Molen, R., Joosten, I., Beentjes, T., and Megen, L. 2011 “Dry Ice Blasting for the Conservation Cleaning of Metals.” In Metal 2010: proceedings of the interim meeting of the ICOM-CC Metal Working Group, Charleston, 11 October 2010, pp.96-103. Clemson: Clemson University.
Capability Statement Oct 2016 - Primas Dry Ice Blasting Fire Damaged Heritage Joists and Boards in Perth, WA.
Primas Dry Ice Blasting was instructed by an insurance builder to restore wooden floor joists and boards that had been damaged in a fire. The joists were situated between the basement and ground floor of a three story heritage listed building in King Street, Perth..
The Jarrah floor joists and boards were installed when the building was constructed in the
early twentieth century. The fire, which started in the rear lane, caused charring and smoke
damage to the basement ceiling and ground floor. As the majority of the joists and boards
appeared structurally sound, the insurance builder requested that dry ice cleaning be used to restore these components by removing the charring, soot, smoke damage and odour. The fire had disrupted a busy enterprise which was very keen to begin trading again.
Primas Dry Ice Blasting quickly coordinated with the business owner to complete the fire
restoration work outside of working hours in order to minimise interruption to the business.
The wooden joists and boards were restored using a powerful stream of dry ice.
The charring, soot, smoke damage and odour was efficiently and effectively removed without damaging the Jarrah components. Dry ice blasting slashed the amount of restoration downtime and business interruption and allowed the heritage assets to be saved.