Groco BB-2 Seacock Backing Block, 1250-1500, Rigid Plastic Bulkhead Mount

The Groco BB-2 is a rigid plastic backing block designed to reinforce the hull mounting surface behind a seacock or thru-hull fitting, spreading clamping load evenly and preventing the fitting from crushing or working loose against fiberglass or wood hull material over time. It is built for bulkhead mount installation, sitting between the hull interior surface and the seacock or valve body so that the mounting hardware bears against a flat, solid surface rather than an uneven or flexible hull laminate. The block is molded from durable plastic for corrosion resistance in the below-waterline marine environment where metal backing plates would be prone to galvanic and saltwater corrosion.

This backing block is identified as the 1250-1500 size and is intended for use with Groco thru-hull fittings and strainers in that size range. It measures 9 inches by 7 inches, giving it enough surface area to distribute load across the surrounding hull structure at a typical seacock installation point.

Specifications

• Brand: Groco
• Manufacturer Part Number: BB-2
• Product Name: Seacock Backing Block 1250-1500
• Category: Thru Hull Fittings and Strainers
• Material: Plastic
• Special Feature: Rigid
• Mounting Type: Bulkhead Mount
• Dimensions: 9 inches L x 7 inches W
• Weight: 0.26 pounds
• UPC: 742985170148

Frequently Asked Questions

What is the Groco BB-2 backing block used for? The Groco BB-2 is a rigid plastic backing block that mounts behind a seacock or thru-hull fitting to reinforce the hull surface at the mounting point and help spread clamping load evenly.

Is the BB-2 backing block bulkhead mounted? Yes, the BB-2 uses a bulkhead mount configuration, sitting flush against the hull interior surface behind the thru-hull fitting.

What material is the Groco BB-2 made of? It is made of rigid plastic, chosen for corrosion resistance in the below-waterline marine environment.

What are the dimensions of the BB-2 backing block? The Groco BB-2 measures 9 inches long by 7 inches wide.

How much does the Groco BB-2 weigh? The BB-2 backing block weighs 0.26 pounds.

What size thru-hull fitting is the BB-2 designed for? The BB-2 is designated as the 1250-1500 size backing block for use with Groco thru-hull fittings and strainers in that size range.

Does the BB-2 backing block include mounting hardware? The listing for the Groco BB-2 covers the backing block itself; no separate hardware components are specified.

Why does a seacock need a backing block? A backing block like the BB-2 reinforces the hull behind a seacock so the fitting's mounting fasteners bear against a solid, flat surface instead of an uneven or flexible hull laminate, reducing the risk of the fitting working loose or cracking the hull over time.

Is the Groco BB-2 genuine Groco or aftermarket? The BB-2 is a genuine Groco part, identified by the manufacturer part number BB-2.

What category of marine hardware does the BB-2 fall under? The Groco BB-2 is categorized under thru-hull fittings and strainers as a backing block accessory.