Groco BB-1 Bronze Backing Block for 3/4 and 1 Inch Seacocks

The Groco BB-1 is a bronze backing block designed to reinforce and support 3/4 inch and 1 inch seacocks at the hull or bulkhead. Installed behind the seacock body, the backing block spreads mounting loads across a wider area of the mounting surface, reducing stress concentration on the hull laminate or bulkhead material and helping the seacock installation resist vibration, impact, and the ongoing strain of thru-hull plumbing. Bronze construction gives the block strong corrosion resistance in salt and fresh water environments, matching the service life expected of the bronze seacocks and fittings it supports.

The BB-1 is intended for bulkhead mount applications and is sized to fit both 3/4 inch and 1 inch seacock installations, making it a practical stocking item for boat builders, riggers, and owners performing seacock replacement or new below-the-waterline plumbing installs. Its flat block profile allows it to sit directly against the mounting surface, distributing clamping and bolt-through loads evenly beneath the seacock flange.

Specifications

• Brand: Groco
• Manufacturer Part Number: BB-1
• Material: Bronze
• Product Dimensions: 9 inches L x 7 inches W
• Mounting Type: Bulkhead Mount
• Fitment: 3/4 inch and 1 inch seacocks
• Weight: 0.18125 pounds

Frequently Asked Questions

What is the Groco BB-1 backing block used for? The Groco BB-1 is a bronze backing block that reinforces the mounting point of a seacock, spreading load across the hull or bulkhead surface behind the seacock body.

What seacock sizes does the BB-1 fit? The BB-1 is sized for 3/4 inch and 1 inch seacocks.

What material is the BB-1 backing block made from? Bronze, which provides strong corrosion resistance for below-the-waterline marine use.

What are the dimensions of the BB-1 backing block? The BB-1 measures 9 inches long by 7 inches wide.

How much does the Groco BB-1 weigh? The BB-1 backing block weighs 0.18125 pounds.

How is the BB-1 backing block mounted? It is a bulkhead mount block, installed flat against the mounting surface behind the seacock.

Is the BB-1 sold as a single piece? Yes, the Groco BB-1 is supplied as one bronze backing block.

Will the BB-1 work with any brand of seacock? The BB-1 is sized for 3/4 inch and 1 inch seacock installations generally; check that your seacock's mounting footprint matches the block's 9 inch by 7 inch dimensions before ordering.

Why use a backing block with a seacock instead of mounting directly to the hull? A backing block like the BB-1 distributes clamping and bolt loads over a larger area, reducing stress on the hull or bulkhead compared to mounting a seacock directly against an unreinforced surface.

Is the BB-1 suitable for both saltwater and freshwater boats? Yes, its bronze construction resists corrosion in both saltwater and freshwater environments.