The Marine Corps Corrosion Prevention and Control (CPAC) Program operates Corrosion Repair Facilities (CRFs) throughout the world in locations such as Camp Lejeune, North Carolina; Camp Pendleton, California; Camp Kinser, Okinawa; and Marine Corps Base, Hawaii. In the performance of its mission and in an effort to mitigate the damaging effects of corrosion and extend the useful life of equipment, the CPAC program has partnered with Naval Surface Warfare Center, Carderock Division to identify and research corrosion repair capabilities to make it effective and efficient while complying with environmental and safety regulations.
CRFs are utilized to provide field-level intermediate corrosion mitigation on ground vehicles and tactical support equipment. The main repair process involves surface preparation via abrasive blast followed by application of the Chemical Agent Resistant Coating system. It is a multi-step process and access to the blast booth is a known process constraint.
In an effort to work around the blast booth constraint, the Marine Corps’ CPAC program teamed with the Office of the Secretary of Defense to investigate the benefits of using a portable vacuum blast system. Carderock led the research into the system.
The portable vacuum blast system is a self-contained blast capability in which material is reclaimed at the point of application. This is done utilizing shrouds of bristle material, which prevent the blast abrasive from escaping. The shrouds come in various shapes and sizes to allow for different substrate configurations, such as corners and small crevices. The blast abrasive is then recycled within the system and is available for use.
Due to its ability to prevent loss of abrasive from the blast process and the small quantity (less than 3 cubic feet) of material that is utilized in the system, the portable vacuum blast unit is exempt from the air quality regulations that require abrasive blast operations to be performed within a regulated booth. This opens the door to many possibilities of use for the portable vacuum blast system.
CRFs perform a critical function in extending the life of Marine Corps equipment, and they face the challenge of managing production with space limitation.
“During the corrosion repair process, managing production is like a jigsaw puzzle where you’re trying to move an asset out of one place so you can blast it, and move it to another place to paint it,” Materials Engineer Eric Moffatt said.
One of the most important aspects of this repair process is time. All of the USMC CRFs have a single blast booth capability with multiple paint booths. Therefore, the blast booth often becomes the limiting factor with the amount of production that a CRF can take on. Utilizing the portable vacuum blast system allows the CRF to blast outside of the blast booth – increasing its capacity for throughput.
“With this system, you’re able to keep equipment out of the blast booth and focus on the affected area,” Moffatt said. “This allows efficient production and encourages uninterrupted process flow. Ultimately, this capability can be used on most of the assets that come through a CRF, though it is best suited for small area repairs.”
One major advantage this system offers is the ability to target spot repairs, which saves time and space. Instead of stripping the coating system from an entire asset, the portable vacuum blast system enables CRFs to perform condition-based maintenance when removing coatings.
As a result of this study, the portable vacuum blast system has been deployed for use in all CRFs operated by the Marine Corps.
“The vacuum blast system at II Marine Expeditionary Force (MEF) CRF has been a significant enabler,” II MEF CRF Manager Charles Wolfe said. “During the facility upgrades, in which the blast booth was down for over six weeks, the II MEF CRF used the system extensively. The vacuum blast system allowed II MEF CRF to work on items with localized scaling, flaking, pitting corrosion and areas that would normally require the blast booth. The system significantly mitigated the single point failure of our one and only blast booth.”
Beyond use to promote throughput at the CRFs, USMC CPAC is beginning to realize the full potential of the system for repairs accomplished “on-the-lot.” Recently, the Amphibious Assault Vehicle (AAV) Program Manager approached the CPAC Team for its support of the Common Remotely Operated Weapons Station (CROWS) upgrade for the AAV platform. The portable vacuum blast unit proved to be a force multiplier compared to the use of traditional coating and paint removal tools, which were found to be ineffective/inefficient. Use of the system drastically decreased overall labor costs for the AAV CROWS upgrade versus the use of traditional coatings removal tools by decreasing the time required to remove coatings. So far, the portable vacuum blast system has reduced planned labor hours for a single asset by 62 percent. To put that into perspective, when multiplied by the total number of proposed implementations, over 8,500 labor hours were avoided – equating to more than four years of time.
“Support of the AAV Program was a unique opportunity to showcase the partnership between the USMC and Carderock and employ a new capability that was versatile and increased productivity,” Moffatt said.
The USMC CPAC program continues to look to effectively implement this technology into its repair processes both at the organization and intermediate maintenance activities. Carderock is currently leading an effort to outfit “on-the-lot” capabilities utilizing the portable vacuum blast system as part of a larger effort for enhanced surface preparation and touch up to help decrease corrosion repair backlog.