Just got a call from Superior-Zincs are ALL gone!!

[zinbaad]

Boat was hauled today & up on a lift for genny installation, just got a call from Rob at Superior that ALL the Zincs are gone, shaft, donunts on tabs & rudders and no block zinc in the stern. Gone, bolts left!! When boat was surveyed back in November I remember seeing all zincs in place, 5" were down to about 4" (didnt recall the block zinc in stern). thats about 5 months ago.
I am not sure if zincs were eatin up to quickly but I am sure going to keep a close eye on them this season.. Might have to switch Marinas?
Any suggestions?
Guess I'll test for stray currents at slip
Wonder how well a Galvanic isolater would really work

[Russell]

Did you happen to tap on the zincs during the survey? As they wear down they sometimes dissolve in a nonuniform manner leaving what looks like a nice piece of zinc but if you touch it it will crumble. I think that is why they say to replace them if they are half gone. If that is not the answer you might benefit from an isolator.

[jcollins]

Unless you just don't like the marina, I wouldn't switch. It can happen at just about any marina. Stray current will do it. Considering there aren't many boats around you this time of year, I would approach the manager. But, the isolater should take care of the problem.

OTOH it could be a zinc thief.

[zinbaad]

Took a ride out to Port Washington to check out Mahalo on the lift. Upon examination
NO BLOCK ZINC or Trim tab zincs were ever installed (anyone else have that prob)
So I will have to drill & install for a new BLOCK and 2 trim tab zincs for sure. The shaft zincs were gone, saw what was called burn marks on shafts. One rudder had a small 1" circle of zinc left. Guess I will have to don my Scuba and do a few checks over the summer (of course OUT of the Marina,,zap zap)
I will check for stray current around slip.
I will do further investigation to Gal Isolater ( some have said some units are worthless)
to Continue

[Carl]

If you have the bennit trim tabs, they make a zinc that goes onto the two bolts that hold the cylinder to the tab. No drilling required and the set comes with new longer bolts. I got mine from boatzincs.com.

[RicM]

A galvanic isolator increased my zinc life about 50%, but that's only one possible cause of zinc erosion. In a marina with lots of boats on shore power 24/7 I would be surprised to see zincs last more that 6-8 months. Many folks that leave their boats in over the winter have an auxilury zinc that they lower overboard when the boat is not leaving the dock for extensive periods of time. You can always add additional zincs. Although you will read about "over zincing" it only applies to wooden boats. You cannot "over zinc" a fiberglass boat.

Here's more than you want to know from our old buddy David Pascoe:
http://marinesurvey.com/yacht/corrosion_2.htm

[jleonard]

Go for a slip with an I/O as your next slip neighbor. All the sray will go to his outdrives.

[zinbaad]

happened to don a mask and take a look at the "New" double shaft zincs, tabs & ruuder zincs installed in april this year....june 28th and already 1/2 gone (2 1/2 months) or more.ggrrrrrrr
going to look into a galvanic isolater.. Any recomendations

[Carl]

Do a little research on the internet and spend the extra bucks for one that "fails safe". You wont be sorry you spent the money for this. It will save you the cost in zincs in one season.