New York Sea Grant's
Marina Pollution Prevention Web Site

Section 2: Painting & Fiberglass Repair - Abrasive Blasting:
Plastic Media Blasting

Plastic Media Blasting

• Different paint removal technologies can be used as BMPs to eliminate or, at least, contain paint chips and dust associated with hull preparation activities. Special equipment, products or procedures can also help reduce the amount of waste material generated and ensure it does not get into the environment.
  
  New abrasive hull blasting technologies utilize a process to reclaim and reuse media made of plastic. In this procedure, the boat must be completely enclosed to trap the media and paint waste. The collected mixture is fed into specialized equipment (located in the truck in the photograph) which through a sifting process separates most of the paint dust and chips from the media, which can then be reused. In addition to containing paint dust and chips, this process can significantly reduce the amount of material that has to be disposed of when stripping a hull. For example, the plastic media stripping of a 19-foot boat produced a total of 200 pounds of waste and media. The equipment recovered 185 pounds reusable media (containing a small amount of paint), leaving only 15 pounds of paint for disposal.
  
  
  Planning Considerations
  
  
• Specialized equipment and training is required for plastic media blasting.
  
  
• In some areas companies have mobile equipment and will perform this service on site for a set fee.
  
  
• Containment of dust and other debris and recovery of the media can considerably reduce clean up and disposal costs.
  
  
• Since the media can not remove anything harder than itself, these techniques may not be effective for preparing all surfaces. For instance, plastic media may not remove corrosion or barnacles from props, shafts, or rudders. However, it will remove paint without damaging sound gel coat, rubber, chrome or glass surfaces.
  
  
• Some softer media may not work well on very durable, pliable paints (like coal tar epoxies). Paint around edges may have to be removed by hand. Sanding is usually required before painting a blasted hull.
  
  
• Care should be taken when blasting boats that have damaged or blistered gel coats since blasting may open blisters or voids that have to be filled before painting. Even sound gel coat may contain small voids that may have to be filled after blasting.
  
  Cost
  
  Equipment costs for a blasting system that incorporates media recovery and reclamation start at $25,000, not including training or the media. In New York, contractors with their own mobile equipment will blast hulls with plastic media on site for approximately $17 to $18 per foot, where length is calculated as the length of the boat at the waterline plus one-half the beam. (Approximate cost for blasting a "typical" 30-foot power boat is about $630.) Discounts may be available for volume work.