Dry-ice cleaning uses accelerated carbon-dioxide pellets that sublime on impact, leaving little or no spent abrasive media. It can be valuable where water, grit or secondary waste must be limited. However, it is principally a cleaning method. It does not automatically remove corrosion, create a specified profile or make an existing coating compatible with an intumescent system.
Key points
- Use dry-ice cleaning for suitable contamination and access constraints, not as a universal substitute for abrasion or blasting.
- Survey the steel and existing coatings before selecting the method.
- Carry out trials where the response of contamination or coating is uncertain.
- Complete any separate corrosion removal, abrasion or primer repair required by the system.
How dry-ice cleaning works
Compressed air accelerates solid carbon-dioxide pellets towards the surface. Impact, rapid cooling and expansion as the pellets sublime can loosen selected deposits. Because the medium becomes gas, the principal waste is the material removed from the substrate.
The process still requires controls for noise, airborne contamination, ventilation and carbon-dioxide accumulation. A suitable risk assessment and working method are essential, especially in enclosed areas.
Where it can be useful
Potential uses include removing certain oils, grease, soot, residues and loosely adhered contaminants from robust surfaces. It may help in sensitive environments where water cannot be introduced or where recovering large quantities of blasting media would be difficult.
Results depend on the contaminant, bond, substrate, temperature, equipment and access. A representative trial can establish whether the method produces the required condition without damaging sound coating.
What it does not normally provide
Dry-ice cleaning should not be assumed to remove firmly bonded corrosion or mill scale, nor to create a defined abrasive-blast profile. If the specification requires Sa 2½, that is a blast-cleaning grade assessed under ISO 8501-1 and should not be claimed for a different method.
It also does not confirm that an existing primer is compatible. Product identity and condition remain separate technical questions.
Combining methods
A project may use dry-ice cleaning for contamination followed by mechanical abrasion of selected areas, local corrosion treatment and primer repair. The combined process should be written into the method statement and supported by the coating requirements.
Fire Coatings’ dry-ice cleaning service is proposed only where the trial, substrate and intended coating support its use.
Inspection after cleaning
The cleaned surface should be assessed for residual contamination, coating adhesion, corrosion, damage and any further preparation specified. Inspection should take place before the surface is recontaminated or concealed.
Where cleanliness cannot be judged visually, the project may require an appropriate test or acceptance method. The criteria should be agreed before work begins.
Environmental claims need care
The absence of spent abrasive can reduce one waste stream, but the whole process still uses compressed air and carbon dioxide and produces removed contamination that must be managed. It should therefore be described by its practical characteristics rather than labelled automatically sustainable or environmentally harmless.
Frequently asked questions
Does dry-ice cleaning damage steel?
The process is generally non-abrasive to sound steel, but equipment settings and the condition of existing coatings matter. A trial is appropriate where damage is a concern.
Can dry-ice cleaning remove rust?
It may remove loose material in some circumstances, but it should not be relied on to achieve a defined corrosion-removal or blast-cleaning standard without evidence.
Can intumescent coating be applied immediately afterwards?
Only after the surface has been inspected and any additional preparation, compatibility checks and primer repairs have been completed.
Discuss your project
To assess whether the method suits your site, send photographs, coating information and details of the contamination and access constraints.
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