Urgent white powder seacocks

[arch007]

All my seacocks are connected by grounding wire

I have white powder appearing at the seacocks.

I have installed galvanic isolator.

It's not sea water leaks

Checked most of wiring

Replaced Marino plug with smart plug

At wits end what to do next

[arch007]

No one?????

[Pete7]

Most of the forum are in the US, so need to give them time, particularly on a work day.

I think that is sea water creeping out through the threads and forming salt crystals.

Pete

[tkeithlu]

Ditto on Pete's analysis. The resolution of the photo is not very good, but it's appearing at the seams where seawater would appear. If the leak is very small, no water appears, and each bit of dampness evaporates leaving the salt behind. With a larger leak it's washed away.

[tkeithlu]

I recommend that you get another cup of coffee and relax. Your boat is not being consumed by galvanic action. Next time it's out of the water, pull your seacocks, grease them and gasket them, and set it right. In the meantime, put a wrench on those nuts and tighten if they are a bit loose.

[Cadence]

I wouldn't be surprise if it was the same as a battery anode? Try pouring a baking soda solution on it and see if it dissolves. yea or nay it might head you in the right direction.

[Wotname]

My WAG is calcium carbonate or zinc chloride

[s/v Jedi]

The last time I saw that it was a bronze screw touching an aluminum bracket. You don’t seem to have anything aluminum there so I think it’s something else.

I would scrape some away, see if it dissolves in water and if so, taste some to see if it’s salt.

[Mike Banks]

You gave the reason in your first sentence.