View Full Version : Mercathode .. + or - ?

Morgan's Cloud
05-01-2012, 12:28 PM
OK , I just need someone to confirm my suspicion .. remember , I've already admitted to not liking to messing around with wiring/electrical.

I finalised the engine room in the Magnum this morning . Checked the zincs in the exhaust manifolds (yeah , those cool Hi-Teks) re-installed the auto extinguisher and put the 2nd battery back in. Both batteries are new and maybe a bit different than the old ones.
The (red) fuse holder wire for the Mercathode goes to the pos side of the battery , right ? The way everything re-locates , the wire didn't quite want to reach the + terminal but I did find an old link thanks to Phil , and that's what it seems to indicate . (And I've left the fuse out so there won't be any battery drain 'till it goes over )

While we're at it .. Is there a general consensus that the Mercathode system really is effective ?

05-01-2012, 03:59 PM
Does this help? See attached doc.

05-01-2012, 04:04 PM
Or even better.....


05-01-2012, 04:31 PM
As I have mentioned before~
All my boats spend 5-6 months each summer sitting in a NJ saltwater boatslip.

My old Formula had an original Mercathode 1 system installed and protected the in water TRS aluminum outdrive parts very well for 10 + years.
My other neighbors, who just use the factory installed zinc annodes, do not fair as near as well with corrosion & electrolytic damage.

I hear later versions of the Mercathode protection system work even much better !

Morgan's Cloud
05-02-2012, 08:09 AM
Thanks tb . The second sample is almost the same as the link I found from an old post. It's just funny how sometimes even when things are 'right' they don't always look to be.
When it comes to electrical I just don't like to take any chances.

As to the effectiveness of the system , I have to admit that under tortuous conditions and with 2 props the B3 has no electrolysis issues so far.
Of course it helps to always be anal with the zincs and their bonding too .

05-02-2012, 03:34 PM
I have mercathode on a B3 and i feel it helps. After the first few seasons there was not the slightest speck of corrosion on the gear case. I am in a fresh water lake but my other boats have not held up as well corrosion wise, so it does something.

05-02-2012, 03:44 PM
The Navy has been using similar, but much larger, electronic cathodic underwater protection systems on their "mothballed" warship fleets in long term storage since the 1940s.

Make sure all battery system electrical connections, & the outdrive's bonding strap systems are in place; and have good clean electrically bonded contact connections.
You can test these connections with a good Volt/ Ohm Test Meter.