Good To Know Fiberglass Boat Techniques

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Every contemporary boat builder has their own distinct approach and process to fabricating vessels. Some boat builders use a fiberglass chopper gun to help construct a strand while others just say no. Perhaps the biggest breaking point in the boat-building world centers around the chopper gun, which feeds strands of fiberglass, Kevlar or carbon fiber roving through a device, chops it into manageable bits, combines it with resin and catalysts and permits the operator to spray it directly into a mold to build up what's going to become the ship's hull.


Many builders swear by it, but others eschew its usage and rather, hand-lay layers of cut sheets of woven roving fiberglass fabric down and wet it with resin. In both processes, workers use little rollers to create the material lay flat and eliminate any bubbles which may form. Those using a vacuum process to deliver the resin skip this step because the vacuum cleans out any bubbles.


The Human Error Element

Running a chopper gun isn't a task a builder could give into a new-hire. Typically, its owner is among the most skilled employees in the factory for a fantastic reason. If the chopped mix is used too thin, the hull is poorer and subsequent layers of woven roving can "print-through" or show up under the gelcoat, which is normally among the first objects coated into the hull mold as ship hulls are constructed from the exterior in. If the chop mixture is sprayed too thick, the hull will weigh too much and can negatively impact handling and performance.


Who Uses Chop in the Layup?

Producers who produce large quantities of boats adore the chopper gun because it's a quick way to use resin and fiberglass in one step. This isn't only done on entry ships either.


Everglades Boats, founded by the late Bob Daugherty, an industry-innovator best known for his decades-long job at Boston Whaler, pioneered a unique boat-building process named RAMCAP. Rather than the usual way of pumping liquid foam into voids after the deck is in place for flotation and acoustical dampening, Everglades creates precision foam parts in their molds and puts them along with a moist bed of fiberglass chop that's sprayed evenly into the mold.


The foam they use weights a hefty 6 pounds per cubic foot rather than the more prevalent 2-pound material typically utilized and becomes an essential part of the hull's structure. The chopper gun is then used to seal it and bond fiberglass to the foam. The deck cap is then put on and is put under vacuum for 24 hours, creating a one-piece hull that is incredibly strong.

Builders like Sea-Ray, Ranger and Malibu use the chopper gun to lay down the first layer of fiberglass to get around the pattern of woven roving from showing under the layer of gelcoat.


Resin And Hardening Agents

After layers of woven roving cloth are laid into position and impregnated with resin and hardening agents to build the hull up to its desired depth. Extra layers of chop can be added along with coring material to build up the desired depth of a strand. Chop is easier to use in areas like corners and complex contours in the mold. Hand-laid cloth is typically cut by an automated CNC machine to exacting standards and in the aforementioned hard-to-cover spots, workers can sometimes have too much overlap, wrinkled fabric or not enough protection, which necessitates a patch.


To make sure that the appropriate amount of chop is being delivered, manufacturers like Sea Ray have a digital display that shows the burden of this chop that's being dispersed to allow the operator to meter it into the correct specifications for that particular hull.


Vacuum Infusion Technology In Boat Building

Some companies handle the matter of woven roving print-through differently. It is produced and marketed by the weight per square foot to be used in various applications.


In accordance with Tony Bonadeo,"We love it as the material goes on nice and even." Bonadeo uses the resin-infusion technique for his hulls and bigger parts where all the laminates are laid out dry, bagged and put under vacuum. The resin is then pulled through the fiberglass and other laminates such as Kevlar and carbon dioxide. "This process provides the laminate a far better resin-to-cloth ratio," said Bonadeo. "This makes it stronger and lighter. It will need more forethought and is more costly but the results are worthwhile."


The Intrepid Way: High-End Custom Boat Building

Another high-end builder of custom ships that employs the hand-laid, vacuum-infused resin technique is Intrepid Powerboats, known for its no-compromise approach to boatbuilding. "We started doing it more than 20 decades back," explained Intrepid president Ken Clinton, "and it provides many advantages over the conventional hand-laying process. The problem with the way we used to do it's when you'd apply the resin, any excess had nowhere to go; a boat hull is like a bowl and it just sits there. Now, we lightly paste each piece of fabric -- that is cut and labeled by our Eastman machine -- and put it in place. Then, we bag it, place it under vacuum and the resin is pulled through. With this process, if there is any surplus, it gets removed by the vacuum."


Hand-Laid Fiberglass Issues

Hand-laid hulls are not with their potential issues either, based on Clinton. "It is important that you train your teams to be consistent when it comes to the method of laying all of the material. You shouldn't use a lot of glue between the layers, so see your overlaps, and be careful with the best way to wrap your cloth around some of the tougher contours in your tooling."


Another concern with the vacuum-infusion procedure, based on Clinton, is that the results are hard to inspect properly afterward. "When the infusion is complete, you merely have a visual review possible for anything above the center that is facing you. Anything below the core doesn't have any way of being viewed because of the gel-coated surface on the opposite side. That's what induced me to go the way of an infrared inspection. By warming the part and watching it with the camera, it allows you to see the different densities cooling at various rates. When there is dry material that didn't get wet beneath the center you'll have the ability to see it using the camera since it's less compact and cools at a different rate, therefore, allowing you to be aware that there is an issue"


The main takeaway is that to create a superior fiberglass boat that you require great employees and businesses which pay their employees well. Developing a good work environment and instilling a culture of excellence provides builders a huge leg-up on the competition, regardless of which methods they employ.


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