air conditioner discharge splash

[a64pilot]

Originally Posted by sailormed

At the risk of thread deviation I have to admit that our boat has the same stupid installation. The seawater outlet of the AC is about 2,5 feet above the water. So I intend to lower the thruhull to about 1-2 inch above the water line (and keeping the high loop in the hose). But the years of splashing seawater have left their trace in the form of a crust of salt on the gelcoat.
How do I remove this? Seasalt is pretty resistant to all solvents, acids, etc. Any one has a solution?

An acid, likely Mary Kate’s on and off will work.
It’s not salt, it’s I believe calcium carbonate.
Don’t get it on you, it will burn, but it’s specifically made to clean hulls, I have always used it to remove “tea stains” you get on the bow from tannic water.

[sailormed]

Thanks for your suggestion. I will give acid a try (HCl) first to see if there is a reaction, but I am afraid it is pure NaCl, it looks like white salt on the hull.