Freeman Marine Deck Rings & Coamings (2400 Series)

Welcome to Bövik Marin AB – authorized distributor of genuine deck rings and coamings for Freeman Marine cast deck hatches. The coaming forms the essential structural foundation for completely flush, watertight deck integration across commercial vessels, workboats, and motor yachts.

Freeman deck coamings are engineered in three distinct metallurgies to match the host hull structure. Coamings are either welded directly flush into metal decks or through-bolted into composite, fiberglass (GRP), or timber working decks.

💡 Relocating an existing Freeman hatch onboard?

If you already have a complete Freeman hatch and plan to relocate it to a new deck position during a refit, we strongly recommend ordering a new replacement deck ring rather than attempting to cut out the existing coaming. Cutting or burning out a welded coaming, grinding away weld seams, and prepping it for re-welding is extremely labor-intensive — and severe thermal stress inevitably leads to heat warpage (distortion). A warped coaming destroys planar alignment, preventing the hatch from sealing watertight. A brand-new factory coaming saves costly yard labor and guarantees an immediate, reliable watertight seal.

Select coaming based on host deck material:

1. Aluminum Rings » For direct welding into aluminum decks or pre-drilled bolt-through installation on composite, fiberglass (GRP), and timber decks. Ideal for: Aluminum hulls, patrol craft, workboats & GRP decks.

2. Steel Rings » Heavy-duty weld-in steel coamings for commercial steel decks. Treated for optimal structural weldability. Ideal for: Trawlers, tugs, work barges & commercial steel hulls.

3. Stainless Steel Rings » Marine-grade stainless weld-in coamings for specialized environments demanding superior corrosion defense. Ideal for: Chemical tankers, research vessels & bespoke yachts.

Technical Guide: The Critical Role of the Deck Coaming

The deck ring (coaming) forms the structural interface between the vessel's hull and the Freeman hatch assembly. For the quick-acting dogging mechanism to operate effortlessly and seat the gasket with uniform compression, the coaming must remain perfectly planar and free from torsional warping.

1. Specifying the Right Profile: Compression vs. Knife-Edge

Freeman manufactures coamings in two structurally distinct formats that are not interchangeable:

Compression Seal Coamings: Feature a flat raised spigot without a perimeter trough. Requires zero drain plumbing and is ideal for working decks where simple washdown is prioritized.
Knife-Edge Seal Coamings: Incorporate a machined knife-edge rim flanked by a deep perimeter drainage gutter and drain spigot. Deck overspill is captured and routed overboard before the hatch is opened in heavy seas.

2. Installation Methodologies: Welding vs. Bolting

Weld-in Installation (Aluminum, Steel & Stainless): The ring is fitted into the deck cutout and fully welded topside and underside. Welding precautions: To prevent thermal distortion, coamings should be tack-welded in a staggered cross-pattern and joined using short, balanced passes with interpass cooling. Keeping the cover dogged in place or using a rigid jig during welding preserves planar accuracy.
Bolt-in Installation (Aluminum Rings Only): For hulls constructed from fiberglass (GRP), sandwich composites, or timber, Freeman aluminum coamings are installed using through-bolts, marine elastomeric sealant (e.g., Sikaflex 291i), and Tef-Gel barrier paste on fasteners to eliminate galvanic corrosion between stainless hardware and the aluminum flange.

3. Hinged vs. Lift-out Coaming Geometry

If your hatch is hinged (suffix -H or -HK), the coaming incorporates integrated mounting lugs to secure the heavy-duty marine hinge pins. Ensure you specify whether the replacement ring is for a lift-out cover or a hinged assembly when placing orders.

Need Cutout Dimensions, Welding Schedules, or Commercial Quotations?

Bövik Marin AB assists shipbuilders, naval architects, and refit yards with manufacturer CAD templates and certified installation guidance. Contact us for commercial pricing or project inquiries.
Email: info@bovikmarin.se | Phone: +46 (0)31 29 00 75