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Quality Assessment and Recommendations 

During my internship at Invincible, a vast majority of my time on the manufacturing floor was spent observing the process and seeing which defects would arise and how the build process strayed away from the drawings and lamination schedule provided from the naval architect. I spent a lot of time reading the TDS's of the laminating materials that we use and the drawings provided from naval architects, so I would have a full understanding of the problems that arose during different stages of lamination and assembly.

Voids from Styrene Gassing

The build process at the company when I had arrived had an instance where the laminators would laminate glass over the core during the installation step for the core using a bonding compound that emitted styrene gas when mixed with vinyl ester resin. Laminating over and sealing off the core during its cure process would create voids that would permeate through the kerfs of the core creating excess voids in the part that could easily be mitigated with informing the lamination team and slowing the build process down.

Gelcoat Pre-Release

During the curing process, the resins would shrink causing prerelease of the gelcoat from the mold surface. This is caused from excess laminate plies and their superposition from the reinforcements laid immediately after the skin coat process. To mitigate this defect, the reinforcements for these specific areas would be laid after the application of the first layer of knitted structural glass for the surrounding area to give the skin coat reinforcement before the additional reinforcements were applied.

Demolding Stress Cracking

This is an instance of when gelcoat can crack from an impact during the demolding process. These types of defects that come out of the part are avoidable if the operators are coordinated with the demolding process. Maintenance on the plumbing of the tooling to pressurize the space between the part and the mold helped prevent a rough demold of the parts. Further rigging and lifting considerations were performed and implemented to help mitigate these defects and to further promote safety on the manufacturing floor. 

Voids in the Skin Coat

Skin coat voids are the most common defect in FRP manufacturing as it still occurs between the hand-layup and resin infusion processes. As an effort for continual improvement processes, Invincible kept track of voids in the skin coat to understand where in the build such defects arise. After researching different products, I recommended to the board of engineers to switch to a high performance radius compound made by Arjay Technologies. Data collection of this implementation was performed after the end of the internship, so the benefit from the product switch is unknown. 

Hard Top Evaluation

Construction of FRP parts that require adherence of multiple parts such as hardtops is a very difficult manufacturing process. The challenge is minimizing voids and weight while promoting good adherence without affecting assembly processes further down the production line. Solutions for this challenge were a frequent topic among engineers within Invincible. The process used core bonding compound to adhere the closed cell foam to the part and to also adhere the two finished, trimmed parts together. Without changing the lamination schedule, changing the core bonding compound to a different product that was less viscous and lighter was the easiest solution to implement. After researching, engineering approval, procurement, and implementation of the new core bonding compound, the results were less weight, less voids, and greater ease of lamination. 

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