Zincs for SD 20 Saildrives

[fstbttms]

Originally Posted by rancher44

we were actually cleaning the bottom every month and replaced zinics every other month.

I don't understand- you knew that corrosion of the saildrive was occurring but you did nothing to rectify the situation until it was ruined?

[rancher44]

NO. We did not know the extent of the damage until it penatrated the housing.
We were changing the zinic's and running a trace on all grounds.
It is very complicated and was a real mess . I have the old sail drives and one is ok but needs some repair and the otherris toast

[DougB]

Originally Posted by GordMay

“... The engine and saildrive must be connected to the boat’s bonding system. Yanmar saildrives are equipped with a single sacrificial anode that is mounted between the propeller and the drive output shaft housing. The anode is sized to protect the drive ONLY. In most cases additional sacrificial anodes will need to be added to the boat to properly protect the other metal underwater hardware installed on the boat and protect against overloading the saildrive anode. If a bronze propeller is installed on the saildrive additional sacrificial anodes may be needed to maintain the hull potential within safe limits ...”

See Yanmar's Advisdory ➥ http://us.yanmar.com/media/ext/uploa...0Corrosion.pdf

Ed Sherman also has an excellent article on the subject
➥ Portecting your Saildrive | Cruising World

Thanks for the links, Gord. I found them to be very informative.