My Marina called me this week....

[Olly]

My Marina called me this week. My 2004 Sea Ray 300 is layed up for the winter. They were preparing to service the Bravo 3 outdrives and noticed a substantial amount of electrolysis affecting the exterior of the drives. Luckily they can be cleaned up. The trim tab zincs still have a good amount left to them so they are thinking the boat may not be the problem. Possibly stray current from a nearby vessel. Another possibility is a galvanic isolator problem. I'll have to wait until the spring but any suggestions on where to start identifying the stray current? Thanks

[wingless]

This article shows how to test a galvanic isolator.

https://www.boatingmag.com/testing-galvanic-isolator/

[Olly]

Thanks Wingless. This is helpful. I’ll check this as soon as the snow melts and I can get into the boat!

[Seabuz]

There are little stainless wires that make ground connections on the outdrive. Make sure they’re in place. Mercury sells a kit.

[Olly]

Thanks- I’ll check those

[Drago]

The kit is about $25 and comes with instructions. It will only work if your bonding system is correct to begin with

[270SDASE]

What’s cheaper to replace, new sacrificial anode set (~$100) or an outdrive. Start there and see if corrosion still accelerated thereafter. Agree with Seabiz, make sure you have the critical stainless ground connectors too!