Zincs Gone this Year

[Blue Stocking]

Exactly,
I was just making a couterpoint to Don's decision in the previous post.
In a glass boat I definitely bond, with heat shrink, No 8 tinned terminals.

[CharlieJ]

I would perfer to replace zincs than have a fitting corrode away like last year where I found a 1-1/4" fitting that was only being held in by some caulking.

With this bit of info, review Post #11...it certainly appears that you experienced a text book example of stray current corrosion. Look at the tank level indicator for the aluminum tank.

Charlie

[goboatingnow]

In a glass boat I definitely bond, with heat shrink, No 8 tinned terminals.

It's worth pointing out that European builders of grp boats do not as a standard practice bond underwater fittings. I agree with the OP there no point in binding on a grp boat it achieves nothing and can actually contribute to corrosion Most us bonding seems to be for safety return then corrosion protection

Dave

[sailorboy1]

Originally Posted by CharlieJ

With this bit of info, review Post #11...it certainly appears that you experienced a text book example of stray current corrosion. Look at the tank level indicator for the aluminum tank.

Charlie

I blamed the thur problem from last year on the boat being in a marina all winter before I got it. But I still decided to unbond the fittings when I fixed the problem. Since I think I then connected the fuel tank ground to the engine instead of to that fitting (which I now are learned was the wrong thing to do anyway and that the fuel tyank never should have been connected to a fitting of a commion ground, but to the keel bolts instead) and the zincs corroded so fast; I am believing a problem related to the fuel tank somehow picking up or sending out a current.

I'll put a meter on that connection sometime during the winter projects.

The more you look at electrical stuff on a boat it confuese you. Impossible to tell what the builder did verse some owner. Probably why people rewire their boats, just so they know where everything goes.

[donradcliffe]

If the keel is lead and there any possibility that the lead is in contact with seawater, you should not connect the keel bolts to ANY ground. Lead is at quite a bit different potential from SS or bronze, and you will create a zinc-eating battery.