For the Navy, surface preparation for ships and boats is an arduous yet critical task. To avoid corrosion and protect the structure of the vessel, existing surfaces must be cleaned of all remnants of prior paint as well as any element, such as salt or sand, that may have gotten underneath. The most difficult aspect of that work involves coating removal in small or awkward spaces and around bolts, seams, and joints. Sandblasting is the current method for paint removal, which is messy, difficult, and not effective in small, hard-to-reach spaces. A CTMA initiative that recently concluded brought Atmospheric Plasma Solutions (APS) together with the team from Norfolk Naval Shipyard (NNSY) for a demonstration of PlasmaBlast®. The goal was to evaluate the technology on profile impact, cleanliness, and adhesion of the new coating.
Working alongside the team in the Technology and Innovation Lab at NNSY, the CTMA demonstration involved comparing the results from abrasive blasting and other currently used removal methods with results from plasma blasting. Testing included:
- A variety of steel test panels coated with commonly used Navy marine coatings that are applied to shipboard substrates
- Evaluations by several shops and trades at the yard
The difference in cleanliness and profile was assessed, and the results of the demonstrations were very well received due to the ease of the PlasmaBlast Technology compared with the sandblasting method. As an added benefit, the demonstration led the participants to consider several new ideas for how this technology could be beneficial beyond the scope of the project.
“It was awesome to see maintainers bring in portions of grip line for us to demonstrate a spot treatment,” says Glenn Astolfi, president of Atmospheric Plasma Solutions. “This was just a demonstration but anytime a technology can make a maintenance job go faster, it means a ship is back out to sea on schedule.”
Another surprising result was to see how well the PlasmaBlast technology removed sodium chloride, or salt, from beneath the coating, compared with other technologies. When salt gets left on and a new coating applied over it, the metal substrate can corrode, and then the new paint or other coating doesn’t adhere well. Other treatments for this situation tend to abrade the metal substrate, but the PlasmaBlast technology causes no abrasion. Furthermore, in studies where PlasmaBlast was used for coating removal, the paint has stayed on up to 20 times longer.
“This project has been a very good collaboration between our technology and inspiration on solving other challenges,” says Astolfi. “It was great to see the enthusiasm from the painters and to watch the maintainers teaching each other on our technology.”
PlasmaBlast will next go through fatigue testing to determine its impact on load-bearing materials and components. Also, APS is working to modify their technology and their training practices and protocols based on feedback from the maintainers.