Overview

The Lopolight 400-404 is a circular HDPE baseplate that sits between a Lopolight horizontal mount light and the mounting surface. It keeps the light housing from touching metal directly, which helps reduce galvanic corrosion marks and surface wear when the fixture is installed on aluminum, stainless, or painted steel.

This is a non-electrical accessory with 0 mA current draw on both 12VDC and 24VDC systems, and it weighs 2.47 oz (0.07 kg). The light itself is sold separately.

Key features

• HDPE (high density polyethylene) isolation baseplate for Lopolight horizontal mount lights
• Breaks direct contact between an aluminum light housing and a metal mounting surface
• 0 mA current draw at 12VDC and 24VDC
• Lightweight at 2.47 oz (0.07 kg)
• Helps when mounting a horizontal light to a metal hardtop, arch, mast plate, or similar structure

Compatibility and fit

Use this baseplate with Lopolight horizontal mounted lights that call for a circular PE/HDPE spacer under the light. It does not affect wiring or electrical loading; it simply adds an insulating layer between the fixture and the boat.

If your installation uses a separate mounting base or adapter, confirm the baseplate is part of your intended stack-up so fastener length and seating stay correct.

Installation and setup

Dry-fit the baseplate at the mounting location, line up the fastener pattern, and make sure the surface is flat so the light sits evenly. If you bed the assembly, keep fastener holes sealed and avoid trapping water under the light.

Tighten fasteners evenly so the HDPE plate is compressed uniformly, then recheck after the first few runs for any settling.

Use on board

This is a good match for refits where a horizontal mount navigation light is moving onto a metal structure, or when corrosion staining shows up around the base from dissimilar-metal contact. It also helps on boats that see heavy vibration, where metal-to-metal rubbing can scuff finishes over time.

Maintenance and care

Rinse with fresh water during routine washdowns and inspect the mounting area during seasonal checks. If the plate shows deep grooves or deformation from over-tightening, replace it to keep the light properly isolated.