Lesson 19

Card 2.4: Penetrators and Enclosure Sealing

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Format: Teardown + potting practice

Time: 40 min plus cure time

Prerequisites: Card 2.3 (Wire Prep)

Core Question

Every wire that enters the hull is a hole in the boat. A penetrator is how we make that hole a promise instead of a leak. What makes one trustworthy?

Resource (~10 min)

Teardown: pass around a disassembled commercial penetrator. Identify the sealing surfaces, the O-ring, and the potted volume. Where would water try first?
The three sealing strategies: O-ring compression, potting compound, and cable glands. Where each is used on our vehicles and why.

Activity

Pot a practice penetrator: a wire through a fitting, filled with epoxy or potting compound, with proper wire prep (a cleared 2.3 splice sample makes a good insert). Label with your name and the date. After cure, it goes in the dunk tank with a vacuum or pressure assist if available, then gets continuity-checked and inspected.

Clearing This Card

Your potted sample passes the dunk and continuity test, plus a 90-second oral check: “Rank the three sealing strategies by how gracefully they fail, and tell me which failure you would rather have at 4 meters.”

If You Miss This Class

Potting station stays set up for two weeks; cure time means plan ahead. Same tests and check.

Why This Matters

Enclosure floods end seasons. The students cleared on 2.3 and 2.4 are the ones authorized to make and service hull passthroughs on Godzillah and the float.