The fiberglass boat hull
To grasp the Material Monitoring System (MMS) for data acquisition and control that Sea Ray’s engineering team developed, it’s first necessary to understand the process the company uses to create a fiberglass boat hull or other fiberglass part. Parts are formed using a female mold; for Sea Ray’s largest yachts, this mold can be up to 60 feet long, 16 feet wide, and 10 feet deep; a finished yacht hull should weigh 14,000 pounds. The first step in the process is applying a thin layer of mold release compound by hand, which allows pulling the completed hull out of the mold like an ice cube out of a tray. A worker sprays a pigmented resin gel coat inside the mold, which gives the hull its slick surface, deep color and high gloss. The next, and most critical, step is to apply the correct amount of “chop spray” to the part in precise layers. A chopper gun chops fiberglass filaments from a spool into sprayable pieces from 10 to 40 millimeters in length, then combines them with a thermosetting vinyl ester or polyester resin for application to the gel coat. However, without concrete feedback on the amounts of fiberglass and resin being consumed for each area, the quality of the chop spraying process depended in part on an individual worker’s ability to gauge the level of material being applied visually. This made it difficult to ensure that each section of the hull received the exact amount of fiberglass intended for it. Over-spraying not only added to the weight of the hull, but wasted fiberglass and resin.
To grasp the Material Monitoring System (MMS) for data acquisition and control that Sea Ray’s engineering team developed, it’s first necessary to understand the process the company uses to create a fiberglass boat hull or other fiberglass part. Parts are formed using a female mold; for Sea Ray’s largest yachts, this mold can be up to 60 feet long, 16 feet wide, and 10 feet deep; a finished yacht hull should weigh 14,000 pounds. The first step in the process is applying a thin layer of mold release compound by hand, which allows pulling the completed hull out of the mold like an ice cube out of a tray. A worker sprays a pigmented resin gel coat inside the mold, which gives the hull its slick surface, deep color and high gloss. The next, and most critical, step is to apply the correct amount of “chop spray” to the part in precise layers. A chopper gun chops fiberglass filaments from a spool into sprayable pieces from 10 to 40 millimeters in length, then combines them with a thermosetting vinyl ester or polyester resin for application to the gel coat. However, without concrete feedback on the amounts of fiberglass and resin being consumed for each area, the quality of the chop spraying process depended in part on an individual worker’s ability to gauge the level of material being applied visually. This made it difficult to ensure that each section of the hull received the exact amount of fiberglass intended for it. Over-spraying not only added to the weight of the hull, but wasted fiberglass and resin.