Old Capac system

[luckydave215]

I just completed a 2 week haul today, going in for bottom paint soda blasting and the rest of the usual stuff. 15 boat bucks in all.
For the last month or so, I've been noticing some corrosion that looked to me like electrolysis (my starboard main strainer basket was attacked) so of course I spent time while the boat was on the hard buzzing out all the bonding (all fine) sleuthing out any possible current leak, and checking out my Capac impressed current system.
After fooling around with the Capac for two days - during which I discovered many poor connections in the system - I decided to just ditch the old thing and convert to a bonded plate zinc on the transom (just like every other boat on the west coast uses)
I'm still using shaft and rudder zincs, shaft wipers make iffy contact, and the ground path through the oil films separating the parts in the gearboxes is high resistance. The rudder zincs are probably good for nothing considering the bonding system, but aren't hurting anything.
Has anyone else converted?

 

[REBrueckner]

Some stainless steel strainer baskets will exhibit corrosion even when all else is ok. I suspect it due to impurities withinin the SS alloy and if that is the case, replacing the basket will solve the problem. No form of corrosion protection will prevent it, not even a zinc sitting in the strainer basket.

 

[luckydave215]

It wasn't just that strainer, there were "something's going on" indications such as white fuzz on the outside of the strainers all over the boat, the engine zincs were almost gone, and at haul the bottom paint was burned away around most of the underwater metal, the port shaft zinc was gone altogether, and the starboard was not far behind. My diver had inspected them 30 days before and saw nothing unusual.
No pink bronze or metal wastage thankfully, I got to it in time. My first guess before investigation was my that new slip neighbor had some "loose juice".
Anyhow, it was definitely time for Sherlock Holmes to get to work.

 

[habanero]

Dave,

I added a 6x12 plate on the transom and bonded the main bonding system to it. I still use shaft zinc. It's been about 8 months on this plate and still no signs for a change-out. Shafts go quicker.

Mike
55C "Habanero"

 

[spcoolin]

Paint blistering off around underwater machinery is generally an indication of Too Much zinc...Yes you can over zinc...

Steve~

 

[Ross Macdonald]

Dave..I've got the plate connected to the bonding system along with shaft collars..1 on each shaft, buttons on the rudders, small buttons on the kelp cutters for the stabs and a cone zinc on the thruster. Seems to work well. Plate lasts about 6 months, collars a little less. Moving around to 5 different marinas in Mexico last year, some areas were hotter than others. Ross

 

[Daybreak]

Dave,

I thought the white fuzz was salt from water seepage, not a bonding issue. I have a couple areas that have some crystals on them, two on my starboard main next to the heat exchanger and one on the port shaft dripless. Zincs are good. By the way, I took Daybreak off the market-O happy Day!

Ben