Offshore Dive Chambers Refurbished with CO2 Blasting
In January 2017, Specialist Painting Group worked with Dri Ice Global to refurbish seven offshore dive chambers aboard a fleet vessel docked in Frederikshavn, Denmark. The project was commissioned by an offshore and marine service provider after localised corrosion and coating breakdown developed inside the chambers.
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The Challenge Inside the Dive Chambers
Offshore dive chambers are enclosed steel vessels used to support diving operations, and the conditions inside them are demanding. Moisture, condensation and the marine environment all attack the coating, and any corrosion must be dealt with to keep the chambers in safe, working order.
The existing coating system had degraded, with localised corrosion inside the confined spaces of the chambers. The tight, enclosed working environment meant traditional surface preparation methods were not viable.
Why High Intensity CO2 Blasting Was Used
To overcome the access problem, SPG used high intensity CO2 blasting to remove existing coatings, corrosion products and surface contaminants. CO2 blasting uses solid carbon dioxide pellets as the blast media. The pellets turn to gas on impact, so there is no spent abrasive to collect from inside the chamber, only the coating and debris that have been removed.
That makes the process well suited to confined spaces, where removing large volumes of grit would be slow and difficult. On the dive chambers, it delivered a thorough and effective clean. Learn more about our high intensity CO2 blasting service.
Applying a Solvent Free Epoxy System
Once the surfaces were properly prepared, SPG applied a two component, solvent free, modified polyamine cured epoxy system. Solvent free coatings release little or no solvent vapour as they cure, which is a significant advantage in enclosed spaces where ventilation is limited.
The result was a durable protective coating that restored the integrity of the dive chambers and returned them to service for the vessel. Find out more about our protective coatings services.
Coating Work in the Offshore and Marine Sector
Offshore and marine assets operate in some of the most corrosive environments there are. Successful coating work depends on choosing preparation methods that suit the space and the vessel’s schedule, and on coatings designed for the conditions. Industry bodies such as the Institute of Corrosion support good practice across the sector.
Planning a Coating Project
Every successful coating project starts with understanding the condition of the existing coating and the steel beneath it. A survey identifies where the coating has failed, how far corrosion has progressed and whether the old system can be overcoated or needs to be removed completely. That information shapes the choice of surface preparation method and the new coating specification.
SPG supports asset owners through each of these stages, from coating inspection and specification advice through to preparation and application. Projects such as the offshore dive chambers show how the right plan, agreed at the outset, keeps work safe, efficient and on programme.
Choosing the Right Surface Preparation Method
No single surface preparation method suits every job. Abrasive blasting, UHP water jetting, mechanical preparation, CO2 blasting and RPR heat induction each have strengths depending on the substrate, the coating being removed and the environment around the work. On the offshore dive chambers, the method was chosen to suit the structure and its setting. Assessing these factors early helps avoid delays and reduces risk once work begins. Where blasting is not practical, we can also advise on UHP water jetting and other methods.
Why Choose SPG
Specialist Painting Group has delivered industrial coating projects since 1997. Our operatives are ICATS certified, and we hold RISQS, SafeContractor, ISO 9001, ISO 45001 and ISO 14001 accreditations, giving clients the competence, safety management and quality systems they expect from a specialist contractor.
Explore the sectors we work in, or contact us to discuss your offshore or marine assets.
