Sportsman Insider: Capping The Open 402

The build of the all-new Open 402 continues to take shape inside Sportsman Boats’ factory, and this week’s Insider update shows just how far this flagship has come. Prototyping a boat of this size demands patience, attention to detail, and plenty of problem solving. The job isn’t just turning a computer design into a real boat—it’s also about developing the playbook for the production team so the full build process runs smoothly in the future.

From the bare hull we first saw, the Open 402 has now become a fully rigged and capped boat that’s nearly ready for final assembly.

Building the Molds

Before any part can be produced, the team must first create its mold. This work happens in the mill room on a five-axis router, familiar to those who have watched Behind the Glass. The router cuts a plug, which is then used to form the inverse mold. That mold is carefully freed from the plug with wedges and air, then lifted with the help of a large crane truck. Once supported by its steel frame, the mold can move through the plant where lamination begins.

Gel coat, skin coat, and dry loading for infusion all follow. Once bagged, vacuum lines are attached and resin is infused to yield lightweight, strong parts with an excellent strength-to-weight ratio.

Precision in the Aluminum Shop

While lamination moves ahead, the aluminum shop is busy fabricating the D-tubing frame structure that will support the console, leaning post, and hardtop. This process starts by creating a jig—fiberglass console, leaning post, and hardtop fixtures that guide the aluminum work. With the jig in place, the team can weld the frame with precision and repeatability, ensuring every Open 402 gets the exact same structure built to the highest standard.

The Capping Process

One of the most exciting stages of the build is capping—the moment the hull and deck are joined together. The team begins with a dry cap, setting the two halves together without bonding agents to test fitment. The goal is a snug, even fit all the way around, like a Tupperware lid sealing perfectly into place.

Once adjustments are complete, the real bonding begins. Methyl methacrylate is carefully applied along stringers and bulkheads, avoiding areas where overflow could be visible. The deck is then lowered onto the hull, secured with fasteners along the pinning flange, and cleaned before being permanently united. From this point on, the Open 402 is one boat.

What’s Next

With capping complete, the Open 402 moves rapidly toward final assembly. The team will soon be preparing this flagship model for its public debut at the Fort Lauderdale Boat Show, opening October 29.

The Sportsman Insider continues to give an inside look at how new models come to life. If you’ve missed earlier updates, now’s the perfect time to catch up and watch the Open 402 take shape piece by piece.

If you missed Episode 1 of "The Sportsman Experience" check it out below.