Cruisers Forum
 


Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 11-03-2021, 21:44   #1
Registered User

Join Date: Jun 2019
Posts: 4
Corrosion/electrolysis around engine anodes

I have been noticing over the past 12 months or so an accumulation of "powdery" looking deposits forming around the gasket line of the plates that the engine anodes are fitted to. This is a Yanmar 2QM20, raw water cooled engine. These powdery deposits are only on the joins where the anodes are, not on any other bolt on plates. The anodes will be down to about 40% after 2 years, and this rate of erosion has not changed. I have not altered the electrical system in any way lately; the shaft anode erosion has stayed constant. I am on a swing mooring so no vessels nearby.
The pictures show what the anode looked like when removed. The engine/head metal is still solid with no indication of wasting. The powder is very similar to what you see on the terminals of a battery.
Should I be worried? Or are the anodes doing exactly what they are supposed to do - sacrifice themselves?
The electrolysis/power cleaned off easily, and I fitted a new anode and refitted it all.
Thanks
Michael
Attached Thumbnails
Click image for larger version

Name:	anode2.jpg
Views:	16
Size:	321.7 KB
ID:	234354   Click image for larger version

Name:	anode3.jpg
Views:	11
Size:	355.1 KB
ID:	234355  

Click image for larger version

Name:	anode4.jpg
Views:	11
Size:	213.2 KB
ID:	234356   Click image for larger version

Name:	anode5.jpg
Views:	12
Size:	208.1 KB
ID:	234357  

Click image for larger version

Name:	Anode1.jpg
Views:	8
Size:	388.0 KB
ID:	234358  
Innovator33 is offline   Reply With Quote
Old 14-03-2021, 12:06   #2
Senior Cruiser
 
tkeithlu's Avatar

Cruisers Forum Supporter

Join Date: Feb 2012
Location: Carrabelle, Florida
Boat: Fiberglas shattering 44' steel trawler
Posts: 3,517
Re: Corrosion/electrolysis around engine anodes

"gasket line of the plates that the engine anodes are fitted to."

These anodes are grounded to the engine, right? Assuming that, they are doing their job and you can move on to the next problem. Hey, you noticed and came to ask. It's the owners who don't see such things who need to worry.
__________________
Never let anything mechanical know that you are in a hurry.
tkeithlu is offline   Reply With Quote
Old 14-03-2021, 13:22   #3
Registered User

Join Date: Nov 2014
Posts: 1,314
Re: Corrosion/electrolysis around engine anodes

Often called salt creep, it doesnít seem to hurt anything. Itís probably calcium carbonate precipitating out and leaching thru the gasket surface. You see it on salt water cooled engine blocks, seawater cooled oil coolers, heat exchangers, etc.
DougR is offline   Reply With Quote
Old 16-03-2021, 07:56   #4
Marine Service Provider

Join Date: Sep 2014
Location: Auckland, NZ
Boat: Compass 790 , 7.9 metres or 26 ft
Posts: 2,416
Re: Corrosion/electrolysis around engine anodes

All is normal re anode but your gasket is leaking a tiny amount. Best to use a thin smear of silicone on both faces & let it go off before you install the gasket I have found. Don't know how much your 2QM20 vibrates but if its anything like our YSM8 you need to use threadlocker on the bolts as well.
This method worked for me to stop the salt creep.
If you keep your boat at a dock with fresh water available its a good idea to put a tee & valve in the water intake hose & flush your engine after use to extend anode life if you wish. Probably extends block life & lessens buildup in cooling galleries as well. Use a hose from the tee with into a bucket of fresh water to suck fresh water up into engine whilst its running & water intake seacock is turned off.
Dont forget to shut valve on tee after you have flushed it.

You can probably put a water hose into the tee but you need to get the pressure right I imagine. I havent done it that way.
Compass790 is offline   Reply With Quote
Reply

Tags
corrosion, electrolysis, engine

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Any DIY portable anodes to prevent galvanic corrosion? Joe from ny Electrical: Batteries, Generators & Solar 22 21-04-2021 17:11
Anodes? We Don' Need No Stinkin' Anodes! fstbttms Construction, Maintenance & Refit 11 10-01-2021 09:21
Fiberglass corrosion around anode bolts from electrolysis maybe Ellstrom Electrical: Batteries, Generators & Solar 13 17-08-2019 22:48
Zinc, Anodes, & Electrolysis….Huh? :) Trident50 Construction, Maintenance & Refit 21 04-10-2015 07:12
Corrosion & electrolysis mixing bronze with alu Srah 1953 Propellers & Drive Systems 3 28-11-2012 16:41

Advertise Here


All times are GMT -7. The time now is 15:05.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.