Q: Will Dry Ice Blasting Remove Rust?
A: The short answer is NO. We get this question all the time since rust is one of the most common contaminants in any industrial setting. Since Dry Ice Blasting is a NON-ABRASIVE process, it will not profile a metal surface in any way. Surface rust will blast away under higher pressure, but the underlying compromised metal will not be affected at all.
Q: Will Dry Ice Blasting remove paint?
A: Paint is a very general term. Coatings are as dynamic as the surfaces they are applied to. Some can be removed very successfully, and others are not phased. They beauty of Co2 Blasting paints, is that we can clean contamination from painted surfaces without damaging the actual coating. Just call and ask about your particular application, maybe it will be a good fit….and no, it won’t remove the paint from your car with a result that you would be satisfied with.
Q: What is dry ice?
A: Dry Ice is the solid form of Carbon Dioxide (CO2). CO2 is a colorless, tasteless, odorless gas found naturally in our atmosphere.
Q: What is dry ice blasting?
A: Dry ice blasting is similar to sandblasting, 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.
Q: How does the process work?
A: 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 during the process of dry ice blasting. This causes a breakdown of the bond between two dissimilar materials.
Q: What happens to the contaminate?
A: Contaminants can be dry, wet, hard or soft. Dry contaminates will break up into small chips and can be swept up or vacuumed. If the particles are large enough, they do not become airborne. If the contaminate is wet, such as grease or oils, the stream will move or push the liquid away much like a high pressure water stream would, except that the surface where the contaminate was will be dry and clean. To prevent redeposition, the operator should work in a methodical way, from the top down.
Q: Do the contaminates or dry ice pellets ricochet?
A: Upon impact, dry ice pellets sublimate to a gaseous state and therefore dry ice particles typically do not ricochet. The removed contaminant is usually washed away by the blast jet stream and does not come directly back into the blast gun vicinity; however, safety glasses must be worn at all times during the operation of the machine.
Q: Can you use dry ice blasting to clean hot production equipment online?
A: Yes. In fact, dry ice blasting cleans faster when the substrate is hot.
Q: Does dry ice blasting cool the substrate?
A: 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. For example, a 30 inch (76.2 cm) by 30 inch (76.2 cm) rubber mold may have an initial temperature of 325°F (162.8°C). After the tool has been blasted clean (approximately 12 minutes), the temperature of the mold is about 300°F (148.9°C).
Q: Will the temperature drop damage the hot mold?
A: 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.
Q: Will the process create condensation?
A: Condensation occurs when the temperature of the substrate falls below the dew point. The dew point varies with climate and the daily weather patterns. When cleaning hot substrates, condensation will rarely occur because the temperature of the surface will stay above the dew point. If condensation does form, you can control it by using heaters, heat lamps, or blow off devices.
Q: How portable are the dry ice blasting machines?
A: One person can easily roll any of the machines around the plant floor without any special equipment. They fit in service/man elevators and through standard doorways.
Q: Is it safe to use dry ice blasting outside?
A: Yes. CO2 dry ice is safe to use in outdoor blasting applications. In fact, many organizations have given Cold Jet® their stamp of approval for the use of dry ice in outdoor blasting applications, including the California Environmental Protection Agency.
Q: What are the primary safety issues when dry ice blasting?
A: One 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.
Q: How loud is the system?
A: Its loud, so just wear hearing protection.
Q: Is it okay to blast in an enclosed area?
A: 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 buildup.