Prop Shaft Bonding Brush Earthing strap copper version

This unique bonding mechanism has a copper plate (ideal for non rusting and electrical conductivity) unlike a brass strap which has about 4 times less conductivity than copper. The pure copper offers the lowest resistance (which is what is required as you are perhaps only looking at.02 of a volt difference between the electron flow (unprotected) and no flow (protected)) Because the differential that can cause the electrolysis is so low (as mentioned above, just.02 of a volt) it is essential that resistance of the linking between the hull outlets is kept to an absolute minimum, thus copper at all stages.

Even the carbon brushes are the best of Japanese fuji carbon (larger copper content than most other common brands) adding to the low to no resisitance required. This can also help majorly reducing radio frequency noises from other machinery. It has long wearing metallic graphite brush on copper strap.

The anode brush on the end that sits against your propeller shaft (and/or your rudder shaft ) provides a connection from the shaft, with normally an anode that is on the outside of the hull in close proximity to the shaft and ship bonding systems.

Main use is bonding for continuity, to link in with other anodic properties. (zinc or alloy anodes bolting through the hull ) and then linked by heavy guage tinned copper wire (some use 6mm squared) from anode to bonding brush, ideally soldered and attached from anode inside the hull to the bonding brush creating the same voltage at each point.

Be aware in an aluminium boat, any brush sitting on a high reving shaft will emit small amounts of copper over time (brushes are in starter motors, alternators.) so a small saucer size captive area to retain and avoid any dust from the brush can be contained.

Dimensions of copper strap:

Length: 350mm

Width: 18.8mm

Thickness: 3.3mm