Dry Ice Cleaning: Frequently Asked Questions

Arctic Fox Dry Ice Cleaning: FAQs

Here are some answers to frequently asked questions – if your question is not answered or you want to discuss a specific project please do call on 01892 886484 contact us on our contact form.

Dry Ice is the solid form of Carbon Dioxide (CO2). It is also known as Cardice. CO2 is a colourless, tasteless, odorless gas found naturally in our atmosphere.

Dry ice blasting is similar to sand blasting, bead blasting, or soda blasting where a media is accelerated in a pressurized air stream (or other inert gas) to impact and clean a surface.

All other media blasting creates a secondary waste stream – which is more costly to dispose of. Dry ice sublimates (vaporizes) upon impact with the surface. All that remains is the original dislodged contaminant to dispose of which will be cheaper because of the reduced volume. There will be no blast media entrapment issues and often no or minimal dismantling of machinery will be required drastically reducing the amount of downtime.

Unlike other blast media, dry ice has a temperature of -109°F (-78.3°C). Because of the temperature difference between the dry ice particles and the surface being treated, thermal shock occurs, breaking the bond between two dissimilar materials.

Contaminants can be dry, wet, hard or soft. Dry contaminants will break up into small chips and can be swept up or vacuumed. Contaminant particles will become airborne and then fall to the floor to be swept up. Containment is a point that may need to be considered. If the contaminant is wet such as grease or oil, the dry ice blasting stream will move or push the oil or liquid away much like a high pressure water stream would, except that the surface where the contaminant was will be dry and clean. To prevent re-deposition, the operator should work in a methodical way, from the top down.

The dry ice particles disappear back into the atmosphere from whence they came. The removed contaminant is usually washed away by the air stream and does not come directly back but the contaminant particles can ricochet so operatives must wear safety glasses.

Dry ice blasting will not damage the substrate. The size of the dry ice pellets and their velocity can be optimized to remove the contaminant while remaining non-abrasive to the substrate. Dry ice blasting can clean delicate chrome or nickel plated tools, soft aluminium or brass alloys, wire insulation and even circuit boards – all without causing damage. NB when dry ice blasting wood or listed buildings if the surface is softer than the contaminant dry ice blasting may damage the substrate – in these situations a trial is recommended.

Yes. In fact, dry ice blasting cleans faster when the substrate is hot.

Yes, but not dramatically. The amount of cooling depends on the substrate material, the dwell time of the dry ice blast stream, and the dry ice usage.

Generally, no. The temperature change of the surface being cleaned is small and the corresponding tensile stress will be well below the point of what most molds will encounter during normal heat treatment.

Condensation occurs when the temperature of the substrate falls below the dew point. The dew point varies with ambient temperature. When cleaning hot substrates, condensation will rarely occur because the temperature of the surface will stay above the dew point. If condensation does form, it is easily controlled by using heaters, heat lamps or blow off devices.

Yes. CO2 dry ice is safe to use outside – but the noise may be problematical.

Yes, with proper ventilation. Because CO2 is 40% heavier than air, placement of exhaust vents at or near ground level is recommended when blasting in an enclosed area. In an open environment, existing ventilation is sufficient to prevent undue CO2 build up. Even though CO2 is non-poisonous, it does displace oxygen in the atmosphere. In Confined Spaces air monitors may be needed and operatives may need breathing apparatus. Arctic Fox Dry Ice Cleaning can provide this.

One safety issue is to protect workers from moving parts. Our dry ice blasting equipment is designed so that workers do not have access to moving parts without shutting down the system. Another concern is the temperature of the dry ice. At -109°F (-78.3°C), we recommend wearing gloves when coming in contact with the dry ice. Eye and ear protection should be worn at all times.

Yes, if the ventilation is adequate. At Arctic Fox Dry Ice Cleaning our operatives may use breathing apparatus as and when necessary. Our operatives have Confined Space certification.

Between 80 and 120 decibels dependent on how the dry ice blasting equipment is being used. The noise is due to the air volume and velocity – which can be adjusted to suit the application. With appropriate hearing protection, an operator can safely operate the system all day. Those working in the near vicinity should also wear ear protection.

With a dual-hose blast system, the dry ice travels in one hose and the high pressure air in another. They are not mixed until just before they exit the nozzle. Single-hose blast systems mix the high pressure air and the dry ice from the time it leaves the machine. Single-hose systems can at times be the better choice when needing a more aggressive clean.