Oil in My Rudder ?

[Matt sachs]

After scaling off a half inch of coal tar epoxy, faring and layers of paint, I found a drain plug in the bottom of my Rudder. I took it out and about a pint of used motor oil cam out. Was this done only to prevent rust inside?

[SteveT]

I would guess so as there is no other benefit. If you do that it pretty well protects the inside of the rudder from any corrosion. Of course if you do get a problematic weld or other damage in the rudder you will be leaking oil into the sea which is a no-no.

[Hydra]

In the past, rudders of large ships were filled with oil to prevent rust. Now, they are often filled with resin and microballoons.

Alain

[SteveT]

All my ships in the last few years have nothing in the rudder voids at all. When the ship is dry-docked the drain plugs are opened and ideally no water comes out. If there is water in the rudder the yard pressure test the rudder with air to find the source of the leaks then weld it up. Replace the plug and then we forget it for another 5 years.

[Matt sachs]

Thanks. I thought thats all it was. I think I'll put some in and slosh it around then pour it out.